We can help you

This can be found at the top right of the home page under: Request access

You are only one step away from your online account! Please observe the following note: You can only register for the online shop with a valid Schiessl customer number. In this case, click on "Request access" in the navigation bar on the right and select the tab "I am already a Schiessl customer". Request access using your customer number and company details.

We will promptly arrange for the activation of your individual prices and send you your login details. You may start usingonline shop in the meantime. So do not hesitate to acquaint yourself with our products. When you have found the product you are interested in, you will be able to request a quote straight away. Please also note that, as wholesalers, we can only provide access to the online shop to commercial customers associated with the industry.

Are you a new customer and do not yet have a customer number? In this case, please use "New customer application".

Feel free to contact us if you have any questions!

You can reach us by telephone at the following number:
+43 662 455 777-0

or in writing by email at:
office@schiessl.at

At the top of the gray menu bar you will find a globe symbol and next to it the country in which you are currently located. To change the country, click the icon and select the appropriate country.

This is found under: My account > My data

The following fields can be modified here:

Password
You can set a new password here.

Personal data
Quickly and easily change your personal data such as name, telephone number or email address as well as your company data such as company name, department and position. You can also upload your company logo.

Data for quote mode
Here you can manage data relating to your company such as your website address, your terms and conditions as well as payment terms and bank information. You can also maintain your introductory and closing texts so that these are automatically filled in when creating an offer. Further information about creating offers for customers can be found under “Create offer for end customer”.

This is found under: My account => Manage your own employees

It's a shame you want to leave us.

To delete your customer account please contact us at the following number:
+43 662 455 777-0

or in writing by email at:
office@schiessl.at

Kindly let us know what we can do better.

If you would like to delete a user, you can do so via the user management"Manage your own employees". Search for the relevant user and the user will be removed by clicking on the recycle bin icon to the right. More information on this topic can be found under"Manage users".

To switch between the gross or net view, click on the eye icon in the gray menu bar at the top left or go to the "My account" area and select "Activate quotation mode" or “Disable offer mode“.

This can be found at the top right of the home page under: Login

To log in, enter your email address and password.

This is found under: Login > Forgot password

Have you forgotten your password? No problem! Simply enter your registered email address. We will send you an email with a link to change your password. Please also check your spam folder if you have not received the email and contact our customer service otherwise.

You can reach us by telephone at the following number:
+43 662 455 777-0

or in writing by email at:
office@schiessl.at

To ensure that you can use our website at any time and anywhere, we have created a platform-independent system to guarantee availability on all end devices.

Only on older versions that go back over 5 years, the compatibility is limited. This can lead to unexpected problems.

This is found under: Company

Would you like to learn more about us? Explore our company page.

Have fun browsing!

At the top right next to the account settings you will find a bell symbol . All news will be displayed in summary.

This is found under: My account > Shopping carts

You can add a product to the shopping cart directly in the product overview, as well as on every detail page of the product. By clicking on the "Add to shopping cart"button, the following window opens: "Please select amount and cart". You can add the product to an existing shopping cart, create a new shopping cart and manage your shopping carts by clicking on "My shopping carts".

This is found under: My account > Favourites

You will find a list of your wish lists here. You can search and filter according to wishlist. You can rename, duplicate or delete individual wish lists here.

If you are in a wish list, you can add or delete products manually. You can also download the DATANORM of the complete wish list here.

This is found under: My account > Shopping carts

A fully featured shopping cart

Your shopping cart does not just contain the products you add to it, you can also configure the following areas:

  • Reference number
  • Supplier
  • Invoice address
  • Delivery and pick-up options


All products in the shopping cart are listed further below. You can also see the order number, description, quantity, as well as the price, subtotal and total price. The DATANORM is also available for download.

It is now possible to orders directly, to send an enquiry, to create a customer quote or to transfer the shopping cart to an employee. More information on managing employees can be found in "Manage users".

This is found under: My account > Open quotes

To request a quote, select "Shopping carts" in the upper right area. A drop-down window appears with an overview of your shopping carts. You can also manage these in the "My account" section. Select the relevant project. Once you are in your project, you can click on the ““Send enquiry”button to request an offer. The request will be forwarded to the relevant sales representative, who will process your quote and get in touch with you as quickly as possible.

You will find an overview of your requests under the "Open quotes” tab. All expired quotes are greyed out - these can be restored if necessary. Quotes that are about to expire are displayed in yellow. Orders can be searched, filtered and sorted.

To mark your product as your favorite, click on the star icon on the right corner of the product overview or in the detailed view. Then the window  "Select wish list"  appears. There you can put the product in an already existing list, create a new wish list or manage them by clicking on  “My wish lists” . Your lists can also be managed in the “My Account” area.

This is found under: My account > My orders

A differentiation is made between the following statuses:

  • Order created
  • Processing
  • Goods partially delivered
  • Goods completely delivered
  • Invoiced
  • Completed
     

The status is shown in the order overview as well as in the detailed view.

This is found under: My account > My orders

You will find an overview of your orders here. Here you can see the order date, order number, reference number, order value and order status for each order. You can search, filter and sort orders.

Clicking on the order number of an order will take you to the detailed view. This is where you will find a list of all the products that you have ordered and if required, you can re-order individual products or place the entire order again.

Once the order is placed, the delivery note, invoice and GAEB x97 are available for download here.

This is found under: My account > Manage your own employees

You will find a list of all your created users. There is a pencil icon to the right of each employee. Click this to edit an employee. Personal data, the password as well as the permissions can be changed.

The following permissions can be assigned:

  • View prices
  • Show net prices
  • Show discounts
  • Inventory
  • Process orders view
  • Submit / Review reports
  • Download invoices
  • Download delivery notes

This is found under: My account > Manage your own employees

Do you want several of your employees to have access to our online shop? Simply setup your employees as users yourself. You can even set which functions are visible for which employee. This practical setting allows you to configure your customer account for the different roles in your company. Click on "New user" to create a new employee and assign them the desired rights for the Schiessl Online Shop.

This is found under: My account > Manage your own employees

To delete a user, select the recycle bin icon to the right of the employee you wish to delete. Clicking on the recycle bin will delete the corresponding user.

You will find a number of filter options to the left of your search result for products in the online shop. The filters are adapted to the product range in order to make the selection easier for you. You can, for example, filter by manufacturer, availability, dimensions or properties.

Reset filter
Do you no longer wish to narrow down your search results? You can then deactivate all filters with the "Clear all" button.

You can easily reach your desired product area in the online shop via our product navigation.

To do so, click on "Products" in the main menu on the home page. A menu will now open with the 12 main categories and our offers. Each of the main categories contains further subcategories. Clicking on a product area will show you all matching items from the online shop.

You can then narrow down your search results with various filters (seeFilter functions).

Search suggestions
As you enter your search term, a number of search hits will be suggested to you. These are sorted by categories and provide you with a quick overview of content that matches your search query.

Search results
The search results are also divided into categories so that you can find what you are looking for more quickly. They are displayed in different tabs.

Choose from the headings:

  • Products
  • News
  • Locations
  • Further articles


If a tab is not displayed, there is no search result in the corresponding category. 

This is found under: Service => Request catalogue

Registered professional customers can order our catalogues free of charge!
Simply fill out the order form to receive the printed version of a product catalogue and we will arrange for dispatch immediately. Please state which catalogue you require and the quantity. These will then be sent to the address registered with us. Please specify a different delivery address in the message if you have one.

Order our new free catalogue now. You will find the order form here.

Have fun browsing!

You can clearly see whether a product is in stock or has to be ordered first with the stock information in the detailed view of a product. The product overview features a colour system with symbols to inform you whether your desired quantity is available.

Warehouse information
The type of availability is stated for each product.

There are 3 different types of items:

  • Items from the stocked range: Items in stock
    You are shown how many units are available in which stores.
  • Order item: Delivery item
    Delivery is made on request.
  • Item is not in stock:  Item not available
    A product is no longer available or is only available in a bundle with
    matching products.
     

You can search, filter and sort quotes. Click on the respective item number to obtain the corresponding inventory information. This means you always know immediately whether the product is in our stocked range, whether it has to be ordered first or whether it is no longer available.

This is found under: Downloads

In the "Downloads" section you will find brochures as well as:

  • Promotions
  • Sales
  • Brochures and flyers
  • Datanorm
  • Information
  • Refrigerant reports
  • Catalogues
  • Price lists

This is found under: Company > Schiessl Logo

Our logo is available for download in various formats:

  • eps
  • jpeg
  • png
  • pdf

You will find all information about the product in the detailed view. You will find the gross and net prices next to the product image. These are only visible when you are logged in. This is because the prices have been individually adjusted for you. The quantity and availability are also indicated.

The following sections can be found in the detailed view:

  • Description
  • Scope of delivery
  • Accessories / replacement parts
  • Performance data
  • Downloads (safety data sheets, REACH, RoHS, WEEE...)
  • Alternatives
  • Technical data
  • DATANORM downloads
  • Customers also bought
  • Recently viewed products

High pressure switch in outdoor unit (F12)

 

Preconditions for fault message:

A pressure of 45 bar or higher has been detected by the high pressure switch for an outdoor unit operating in heating or cooling mode.

 

Causes:

1. Dust deposits on the heat exchanger of the outdoor unit

2. Air side short circuit in outdoor unit

3. Faulty circulating pump

4. Insufficient water flow in the system

5. Improper seal in the system

6. Service valve closed

7. Expansion valve or filter blocked

8. Too much refrigerant in the system

9. Faulty high pressure sensor and switch on outdoor unit

10. Faulty circuit board on outdoor unit

 

Fault detection:

Occurs 4x within 20 minutes

 

Further information can be found in this PDF.

Compressor rotation fault (F14)

 

Preconditions for fault message:

The position detection circuit in the compressor has recorded an incorrect speed.

 

Causes:

1. Compressor not connected

2. Faulty outdoor unit circuit board (main board)

3. Faulty compressor

 

Fault detection:

Occurs 4x within 20 minutes Further information can be found in this PDF.

 

Further information can be found in this PDF.

DC fan motor on outdoor unit blocked (F15)

 

Preconditions for fault message:

The speed detected by the hall generator on the fan motor was not between 50 and 2550 min-1.

 

Causes:

1. Shut-off following a short circuit in the fan motor coil.

2. Shut-off due to a broken fan motor coil.

3. Shut-off due to a broken wire to the fan motor.

4. Shut-off due to faulty hall generators in fan motor.

5. Disruption due to faulty board in outdoor unit.

 

Fault detection:

Occurs 2x within 30 minutes.

 

Further information can be found in this PDF.

Excessive power draw (F16)

 

Preconditions for fault message:

The transformer (CT) has detected excessive power draw (27.9 A) by the outdoor unit board in cooling or heating mode.

 

Causes:

1. Too much refrigerant in the system

2. Faulty outdoor unit board (main board)

 

Fault detection:

Occurs 3x within 20 minutes.

 

Further information can be found in this PDF.

Compressor overheat protection (F20)

 

Preconditions for fault message:

The compressor temperature sensor has detected that the compressor casing is above 112 °C in cooling or heating mode.

 

Causes:

1. Faulty compressor temperature sensor

2. Service valve closed

3. Insufficient refrigerant (leak)

4. Expansion valve or filter blocked

5. Faulty outdoor unit circuit board (main board)

6. Faulty compressor

 

Fault detection:

Occurs 4x within 30 minutes

 

Further information can be found in this PDF.

Power transistor module overheat protection (F22)

 

Preconditions for fault message:

The temperature sensor for the transistor module of the outdoor unit has detected a temperature above 112 °C in cooling or heating mode.

 

Causes:

1. Faulty fan motor on the outdoor unit

2. Faulty outdoor unit board (main board)

 

Fault detection:

Occurs 3x within 30 minutes.

 

Further information can be found in this PDF.

Excess current output (F23)

 

Preconditions for fault message:

An output current above 40.1 A ±5.0 A (UD07 to 09CE) or 44.7 A ±5.0 A (UD12 to 16CE) in cooling or heating mode has been measured on the main board of the outdoor unit.

 

Causes:

1. Faulty outdoor unit circuit board (main board)

2. Faulty compressor

 

Fault detection:

The fault persists for at least 7 seconds.

 

Further information can be found in this PDF.

Problem in refrigeration circuit (F24)

 

Preconditions for fault message:

1. In cooling and heating modes, the compressor frequency is higher than the rated frequency.

2. In cooling and heating modes, the operating current is between 0.65 and 1.65 A.

3. In cooling and heating modes, the difference between the water inlet temperature and the fluid temperature of the indoor unit<5 K.

4. In cooling and heating modes, the difference between the water inlet temperature and the fluid temperature of the indoor unit<5 K.

 

Causes:

1. Faulty water inlet temperature sensor or fluid temperature sensor in the indoor unit

2. Service valve closed

3. Insufficient refrigerant (leak)

4. Expansion valve or filter blocked

5. Faulty outdoor unit circuit board (main board)

6. Poor compressor performance

 

Fault detection:

Occurs 2x within 20 minutes.

 

Further information can be found in this PDF.

Problem with switch valve (F25)

 

Preconditions for fault message:

1. In heating mode, the pipe temperature in the indoor unit is below 0 °C with thermostats active.

2. In cooling mode, the pipe temperature in the indoor unit is above 45 °C thermostats active.

 

Causes:

1. Sensor error

2. Faulty connection

3. Faulty outdoor unit circuit board (power board or main board)

4. Faulty switch valve

 

Fault detection:

Occurs 4x within 30 minutes.

 

Further information can be found in this PDF.

High pressure fault in outdoor unit (F27)

 

Preconditions for fault message:

The high pressure switch in the outdoor unit remains open when the compressor is shut off.

 

Causes:

1. Faulty connection

2. Faulty switch

3. Faulty board in outdoor unit (main board)

 

Fault detection:

The fault persists for at least 1 minute.

 

Further information can be found in this PDF.

Fault with water outlet temperature sensor 2 in indoor device (F30)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature values from the water outlet temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in indoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Fault with external temperature sensor (F36)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature valves from the external temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in outdoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Fault with water inlet temperature sensor in indoor unit (F37)

 

Preconditions for fault alert:

When starting and during cooling or heating operation, the measured temperature values from the water inlet temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in indoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Fault with hot gas temperature sensor in outdoor unit (F40)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature valves from the hot gas temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in outdoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Inverter controller fault (PFC, F41)

 

Preconditions for fault message:

In cooling and heating modes, the PFC breaker measures an unusually high DC voltage on the main board of the outdoor unit.

 

Causes:

1. Excess power supply voltage

2. Unequal resistances in the compressor coils

3. Faulty circuit board on outdoor unit

 

Fault detection:

Occurs 4x within 10 minutes

 

Further information can be found in this PDF.

 

Fault with heat exchanger temperature sensor in outdoor unit (F42)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature values from the heat exchanger temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in outdoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Fault with defrosting temperature sensor in outdoor unit (F43)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature values from the defrosting temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in outdoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Fault with water outlet temperature sensor in indoor device (F45)

 

Prerequisites for fault alert:

When starting and during cooling or heating operation, the measured temperature values from the water outlet temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in indoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Transformer in outdoor unit is open (F46)

 

Preconditions for fault message:

A transformer (CT) has been determined to be defective if the operating frequency of the compressor (≥ rated frequency) and the transformer’s measured power draw (less than 0.65 A) do not match for a period of 20 seconds.

 

Causes:

1. Transformer is faulty

2. Faulty outdoor unit circuit board (main board)

3. Faulty compressor

 

Fault detection:

Occurs 3x within 20 minutes

 

Further information can be found in this PDF.

Fault with evaporator outlet temperature sensor in outdoor unit (F48)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature values from the evaporator outlet temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in outdoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Fault with bypass outlet temperature sensor in outdoor unit (F49)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature values from the bypass outlet temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in outdoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

High pressure protection during cooling in outdoor unit (F95)

 

Preconditions for fault message:

A pressure of 40 bar or higher has been detected by the high pressure sensor in the outdoor unit.

 

Causes:

1. Dust deposits on the heat exchanger of the outdoor unit

2. Air side short circuit in outdoor unit

3. Two-way service valve closed

4. Faulty fan motor on the outdoor unit

5. Expansion valve or filter blocked

6. Too much refrigerant in the system

7. Faulty high pressure sensor in outdoor unit

8. Faulty board in outdoor unit (main board)

 

Further information can be found in this PDF.

 

 

Unsuitable unit performance (H12)

 

Preconditions for the fault message:

When starting the cooling and heating operation, the outdoor unit checks the performance combination of indoor and outdoor unit for reliability.

 

Causes:

1. Incorrect models connected to each other

2. Incorrect indoor and/or outdoor unit circuit boards (main boards) used

3. Faulty circuit board in indoor/outdoor unit circuit boards

 

Fault detection:

Incorrect measurement for at least 90 seconds.

 

Further information can be found in this PDF.

Fault with compressor temperature sensor (H15)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature values from the compressor temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in outdoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Fault with fluid temperature sensor in indoor unit (H23)

 

Preconditions for fault message:

When starting and during cooling or heating operation, the measured temperature values from the fluid temperature sensor in the indoor unit are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in indoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Sun sensor malfunction (H28):

 

Preconditions for the fault message:

Error code continues for more than 5 seconds.

 

Causes:

1. Faulty connection

2. Solar sensor defective

3. Faulty inner sub-board

 

CAUTION:

For safety reasons and to avoid component failure, always switch off the power supply before removing and connecting the component

 

Detection of the fault:

  1. Check connection at CN207.
  2. Measure the resistance of the sensor matching characteristic
  3. Change the inner sub-board

Swimming pool sensor malfunction (H28):

 

Preconditions for the fault message:

Error code continues for more than 5 seconds.

 

Causes:

1. Faulty connection

2. Pool sensor defective

3. Faulty inner sub-board

 

CAUTION:

For safety reasons and to avoid component failure, always switch off the power supply before removing and connecting the component

 

Detection of the fault:

  1. Check connection at CN204.
  2. Measure the resistance of the sensor matching characteristic
  3. Change the inner sub-board

 

Buffer tank sensor malfunction (H28):

 

Preconditions for the fault message:

Error code continues for more than 5 seconds.

 

Causes:

1. Faulty connector

2. Buffer tank sensor defective

3. Faulty inner sub-board

 

CAUTION:

For safety reasons and to avoid component failure, always switch off the power supply before removing and connecting the component

 

Detection of the fault:

  1. Check connection at CN205.
  2. Remove sensor from sub-board Measure resistance of sensor and compare with characteristic
  3. Change the inner sub-board

Brand code does not match (H38):

 

 

Causes:

1. Internal and external brands do not match.

 

Detection of the fault:

  1. Check the brand of indoor and outdoor unit; both Panasonic?

    Change outdoor unit circuit board

Low pressure compressor protection (H42)

 

Preconditions for fault message:

In heating mode and after the compressor has been operating for 5 minutes, the pipe temperature sensor in the outdoor unit measures a temperature below -29 °C or above 26 °C.

 

Causes:

1. Dust deposits on the heat exchanger of the outdoor unit

2. Air side short circuit in outdoor unit

3. Two-way service valve partially closed

4. Faulty fan motor on the outdoor unit

5. Insufficient refrigerant (leak)

6. Expansion valve or filter blocked

7. Defective pipe temperature sensor in outdoor unit

8. Faulty board in outdoor unit (main board)

 

 

Further information can be found in this PDF.

 

 Zone 1 sensor malfunction (H43):

 

Preconditions for the fault message:

Error code continues for more than 5 seconds.

 

Causes:

1. Faulty connection

2. Buffer tank sensor defective

3. Faulty inner sub-board

 

CAUTION:

For safety reasons and to avoid component failure, always switch off the power supply before you remove and connect the component

 

Detection of the fault:

  1. Check the connection of the connector to switch off

  2. Check the connector of the sub-circuit board of zone 1 - the circuit board the resistance of the sensor characteristic curve of zone 1

  3. Change circuit board

Zone 2 sensor malfunction (H44):

 

Preconditions for the fault message:

Error code continues for more than 5 seconds.

 

Causes:

1.Faulty connection

2. Remove from sub-board, check sensor properties. Test measurement resistance

3. Faulty inner sub-board

 

CAUTION:

For safety reasons and to avoid component failure, always switch off the power supply before removing and connecting the component Detection of the fault:

 

Switch off the power

  1. supply test plug connection.

  2. Disconnect from the sub-board, check sensor properties. Test measurement resistance

  3. Change circuit board

Fault on the water-side flow monitor (H62)

 

Preconditions for the fault message:

During cooling and heating operation, the water flow is monitored by the flow monitor in the indoor unit in order to detect an interruption in the flow.

 

Causes:

1. Faulty circulating pump

2. Improper seal in the system

3. Faulty connection

4. Faulty flow monitor

5. Faulty circuit board in indoor unit (main board)

 

Fault detection:

The fault persists for 10 seconds (no monitoring for 9 minutes after compressor start-up or restart)

 

Further information can be found in this PDF.

Defective low pressure sensor in outdoor unit (H63)

 

Preconditions for fault message:

When in heating mode, the output signal from the low pressure sensor in the outdoor units gives a value of 0 or 5 V DC.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty circuit board on outdoor unit

 

Fault detection:

Occurs 4x within 20 minutes

 

Further information can be found in this PDF.

Defective high pressure sensor in outdoor unit (H64)

 

Preconditions for fault message:

When in heating or cooling mode, the output signal from the high pressure sensor in the outdoor units gives a value of 0 or 5 V DC.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty circuit board on outdoor unit

 

Fault detection:

Occurs 4x within 20 minutes

 

Further information can be found in this PDF.

Incorrect water circulation in defrost mode 2 (H65)

 

Preconditions for the fault message:

During the defrost process (defrost mode 2) and during the defrost, water flow through the heat exchanger was determined.

Cause:

1. Unwanted water flow through the heat exchanger of the heat pump, possibly caused by an external circulation pump

2. Defective flow switch

3. Defective circulating pump in the indoor unit

4. Defective motherboard

 

Detection of the fault:

Water malfunction continues> 10 seconds.

 

Fault overload protection of the indoor unit electric heating element (H70)

 

Preconditions for fault message:

While the indoor unit electric heating element is switched on, there is no voltage on the indoor unit electric heating element or the overload protection is open.

 

Causes:

1. Incorrect connection of the power supply

2. Faulty connection

3. Faulty overload protection of the indoor unit electric heating element.

4. Faulty circuit board in outdoor unit (main board)

 

Fault detection:

The fault persists for at least 60 seconds.

 

Further information can be found in this PDF.

Fault in the hot water tank temperature sensor (H72)

 

Preconditions for fault message:

If the parameter for the tank connection is set to YES, the temperature values measured by the hot water tank temperature sensor are checked for plausibility.

 

Causes:

1. Faulty connection

2. Sensor error

3. Faulty board in indoor unit (main board)

 

Fault detection:

Incorrect measurement value for at least 5 seconds.

 

Further information can be found in this PDF.

Fault in data transmission with the control panel of the indoor unit (H76)

 

Preconditions for fault message:

In standby, in cooling and in heating mode if there is a fault in the indoor unit control panel

 

Causes:

1. Faulty connections

2. Faulty control panel

3. Faulty circuit board in outdoor unit (main board)

 

Further information can be found in this PDF.

 

Faulty communication between indoor and outdoor units (H90)

 

Preconditions for fault message

In cooling or heating mode, it is checked whether signals received from the outdoor unit are correct during data transmission.

 

Causes:

1. Faulty outdoor unit circuit board (main board)

2. Faulty indoor unit circuit board (main board)

3. Faulty connection between indoor and outdoor units

4. Damaged cabling between indoor and outdoor units

5. Incorrect data transmission due to incorrect waveform of the power supply

 

Detection of the fault:

The fault is present after 1 minute of operation

 

For more information, see this PDF.

Fault overload protection of the indoor unit electric heating element (H91)

 

Preconditions for fault message:

While the hot water electric heating element is switched on, there is no voltage across the hot water electric heating element or the overload protection is open.

 

Causes:

1. Faulty connection

2. Faulty hot water electric heating element overload protection.

3. Faulty circuit board in indoor unit (main board)

 

Fault detection:

The fault persists for at least 60 seconds.

 

Further information can be found in this PDF.

Power supply indoor/outdoor unit faulty (H95)

 

Preconditions for fault message:

The power supply is monitored by the indoor/outdoor unit communication

 

Causes:

1. Insufficient power supply

2. Faulty board in outdoor unit (power supply or main board)

 

Further information can be found in this PDF.

 

High pressure fault in heating mode (H98)

 

Preconditions for fault message:

in heating mode, a pressure of 40 bar or higher has been detected by the high pressure sensor in the outdoor unit.

 

Causes:

1. Faulty circulating pump

2. Insufficient water flow in the system

3. Improper seal in the system

4. Service valve closed

5. Expansion valve or filter blocked

6. Too much refrigerant in the system

7. Faulty high pressure sensor in outdoor unit

8. Faulty board in outdoor unit (main board)

 

Further information can be found in this PDF.

 

Frost protection in the indoor unit

 

Preconditions for the fault message:

During the frost protection control in cooling mode, the refrigerant temperature in the indoor unit drops below 0°C

 

Cause:

1. Faulty circulating pump

2. Insufficient water flow in the system

3. Improper seal in the system

4. Two-way service valve partially closed

5. Expansion valve or filter blocked

6. Insufficient refrigerant (leak)

7. Faulty fluid temperature sensor

8. Faulty circuit board in outdoor unit (main board)

 

Further information can be found in this PDF.

 

With the infrared remote control:
In the event of a fault, the unit is automatically switched off and the timer LED flashes. The error is stored in memory. The type of fault can be determined using the self-diagnosis function and the fault codes:

  1. Press the self-diagnosis button (CHECK) on the remote control for more than 5 seconds to switch on the self-diagnosis mode. The remote control then displays "- -". (No signal has yet been transmitted to the indoor unit, ie there is no beep and the POWER LED does not light up.)
  2. Press the TIMER up or down button, the code "H00" appears (no malfunction) and a signal is sent to the indoor unit.
  3. Press the TIMERup again down. Each time the button is pressed, a new fault code is displayed and sent to the indoor unit.
  4. If the fault code sent matches the actual fault in the unit, the POWER LED lights up for 30 seconds and it sounds
    a 4 second beep. If the fault code does not match, the POWER LED lights up for 0.5 seconds and there is no beep.
  5. If no button is pressed on the remote control for 30 seconds, or if you press the CHECK button again for 5 seconds, the self-diagnosis mode is switched off again. The LED goes out when the device is switched off or the AUTObutton on the unit is pressed.

With the cable remote control (CZ-RD52CP):
In the event of a fault, the device is automatically switched off and the mode LED is OFF. The OFF indicator also does not appear on the remote control. The error code can be read using the remote control as follows:

  1. Press the self-diagnosis button (CHECK) on the remote control for more than 5 seconds to switch on the self-diagnosis mode. The remote control then displays "- -".
  2. Press the TIMER up or down key, the code "H00" appears (no fault).
  3. Press the TIMERup or down key again. Each time the button is pressed, a new fault code is displayed and sent to the indoor unit.
  4. If the fault code sent matches the actual fault in the unit, the POWER LED stays lit up.
  5. If no button is pressed on the remote control for 30 seconds, or if you press the CHECKbutton again for 5 seconds, the self-diagnosis mode is switched off again.

F11 Fault when switching between cooling and heating cycle
 

Preconditions: 4 times in 20 minutes

Check priority:

  1. Switchover valve
  2. Valve coil

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty outdoor unit circuit board.
  4. Faulty switchover valve.

To check and remedy see picture.

F17 Not running indoor unit frost protection

Preconditions:
Only for multi-split inverter systems

Priority check:

  1.  Expansion valve is leaking
  2. Pipe temperature sensor of the indoor unit

Possible causes:

  1. Faulty expansion valve.
  2. Faulty line temperature sensor.
  3. Faulty outdoor unit circuit board.

To check and remedy see figure.

F90 Power factor control

Preconditions:
4 times in 20 minutes

Check priority: Power factor control voltage

  1. DC voltage spike due to voltage supply fluctuation.
  2. DC voltage spike due to compressor malfunction or unequal winding resistance.
  3. Faulty outdoor unit fan.
  4. Faulty compressor.
  5. Faulty PFC circuit of the outdoor unit circuit board.
  6. Faulty choke coil.

For checking and rectification see picture.

F91 Cooling circuit fault

Preconditions: 2 times in 20 minutes

Check priority: No refrigerant (-way valve closed)

  1. Lack of refrigerant (leakage).
  2. Low compression of the compressor.
  3. Service valve closed.
  4. Incorrect measured value of the line temperature sensor or the intake temperature sensor in the indoor unit.
  5. Outdoor unit board.

To check and rectify see picture.

F93 Incorrect compressor rpm

Preconditions:
4 times in 20 minutes

Check priority:

  1. Lack of refrigerant (leakage).
  2. Low compression of the compressor.
  3. Service valve closed.
  4. Incorrect measured value of the line temperature sensor or the intake temperature sensor in the indoor unit.
  5. Outdoor unit board.

To check and rectify see picture.

 

F94: High pressure pressostat in the outdoor unit has triggered

Preconditions: 4 times in 20 minutes

Check priority:

  1. Switch valve
  2. Valve coil
  3. High pressure pressostat
  4. Condenser fan

Possible causes:

  1. Short circuit of the warm blown air.
  2. Outdoor unit fan motor defective.
  3. Line temperature sensor in the outdoor unit defective.
  4. Outdoor unit board defective.

F95 High pressure protection in cooling mode

Preconditions: 4 times in 20 minutes

Check priority:

  1. Short circuit of the warm blown air.
  2. Outdoor unit fan motor defective.
  3. Line temperature sensor in the outdoor unit defective.
  4. Outdoor unit board defective.

To check and remedy see picture.

F96 Compressor overheat protection
 

Preconditions: 4 times in 20 minutes

Check priority:

  1. Refrigerant shortage
  2. Compressor

Possible causes:

  1. Refrigerant shortage (leakage).
  2. Incorrect measured value of the compressor or hot gas temperature sensor.
  3. Pipe kinked or service valve (s) half closed.

F96 Power transistor module overheat protection


Priority check:

  1. Insufficient heat dissipation from the outdoor unit.
  2. Excess refrigerant.
  3. Power transistor defective.
  4. Service valve closed.

To check and remedy see picture.

F98 Protection against excessive total operating current

Preconditions:
3 times in 20 minutes

Check priority:

  1. Refrigerant excess
  2. Insufficient heat emission

Possible causes:

  1. Overcurrent due to compressor malfunction.
  2. Overcurrent due to defective outdoor unit circuit board.
  3. Overcurrent due to defective inverter
  4. Condenser circuit.
  5. Overcurrent due to excessive refrigerant charge

For checking and rectification see picture.

F99 Direct current spikes in outdoor unit

Preconditions:
7 times in a row

Priority check:

  1. Outdoor unit circuit board
  2. Power transistor (IPM)
  3. Compressor

Possible causes:

  1. Compressor fault
  2. Defective power transistor module
  3. Defective outdoor unit board

To check and rectify see figure.

 Fault codes of the multi-split inverter systems using the LEDs on the circuit board of the outdoor units CU-3E23CBPG and CU-4E27CBPG

LED:

 

Note:
Turn the power off, then on. If the green LED A lights up permanently, the outdoor unit circuit board is defective.
 

ATTENTION
For safety reasons and to prevent damage to components, always disconnect the power supply before disconnecting and reconnecting a component.

 

H00 No fault

H11: Communication fault between indoor and outdoor units

Precondition: >1 min after commissioning
Emergency mode: Only recirculated air

to be checked:

  1. Cable connections internal and external as well as circuit boards on indoor/outdoor units

Possible causes:

  1. Faulty expansion valve.
  2. Faulty line temperature sensor.
  3. Faulty outdoor unit circuit board

Check and rectify see figure.

H12: Unsuitable performances of indoor and outdoor units

Priority check: Occurs only with multi systems

Possible causes:

  1. Incorrect models connected to each other.
  2. Wrong indoor and/or outdoor unit circuit boards used
  3. Indoor or outdoor unit circuits board defective.
  4. Incorrect wiring between indoor and outdoor unit.
  5. Data transmission line No. 3 between indoor and outdoor unit interrupted.

For checking and rectification see figure.

 

 

H14: Indoor unit intake temperature sensor

Requirement:
5 seconds long
Priority check: Room temperature sensor (defective or not connected)
 

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

H15: Compressor temperature fault

Requirement:
5 seconds long
Priority check: Room temperature sensor (defective or not connected)
 

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

H16: Transformer in outdoor unit is open

Priority check:
Circuit board in the outdoor unit power transistor module (IPM) compressor defective (compressor too low)

Possible causes:

  1. Refrigerant deficiency.
  2. Transformer defective.
  3. Outdoor unit circuit board defective.
  4. Compressor defective (low compression).

For checking and rectification see picture.

H19: Indoor unit ventilator module blocked

Preconditions: 7 times in series
 

Priority check:

  1. Circuit board in the outdoor unit
  2. Power transistor module
  3. Compressor defective

Possible causes:

  1. Faulty motor connection on the circuit board.
  2. Defective fan motor.
  3. Faulty indoor unit circuit board.
  4. Fan motor mechanically blocked.

For checking and rectification see figure.

H21: Float switch in the indoor unit

Priority check: Float switch

Possible causes:

  1. Condensate pump clogged or no slope
  2. Faulty condensate pump (CN-DRMTR).
  3. Float switch not connected (CN-TH2, connections 1 and 2 for cassettes and CN-FSW, Connections 1 and 3 for duct units).
  4. Float switch defective (blocked in the open position).
  5. Faulty indoor unit ciruit board.
  6. Fan motor mechanically blocked.

To check and remedy see figure.

 

H23: Indoor unit heat exchanger sensor

Preconditions: 5 seconds long
Emergency mode: Operation with fixed compressor operating frequency and fixed fan speed (only cooling)

Priority check: Heat exchanger temperature sensor (defective not connected)

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

H24 Indoor unit heat exchanger sensor 2
 

Requirement: 5 seconds long

Priority check: Heat exchanger temperature sensor (defective not connected)

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

H25 E-ion power module malfunction

Priority check:

  1. Circuit board indoor unit
  2. e-ion power module

Possible causes:

  1. Faulty e-ion module (high-voltage generator for positive charging of the filters).
  2. Faulty circuit board.
  3. Faulty connection or wiring (open or short-circuited).

For checking and rectification see figure.

H26 Air ioniser fault


Priority check:

  1. Indoor unit circuit board
  2. Ioniser

Possible causes:

  1. Faulty air ioniser circuit.
  2. Faulty plug connection.
  3. Faulty circuit board.

To check and rectify see picture.

H27 Outside air temperature sensor

Precondition: 5 seconds long
Emergency mode: Operation with fixed compressor operating frequency and fixed fan speed (only cooling)

Priority check: Outside air temperature sensor (defective not connected)

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

H28 Outdoor unit heat exchanger sensor

Precondition: 5 seconds long
Emergency mode: Operation with fixed compressor operating frequency and fixed fan speed (only cooling)

Priority check: Outdoor unit heat exchanger temperature sensor (defective not connected)

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

H30: Hot gas temperature sensor

Precondition: 5 seconds long

Priority check: Hot gas temperature sensor

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

 

H32 Hot gas temperature sensor 2
 

Requirement: 5 seconds, only for multi-split inverter systems

Priority check: Hot gas temperature sensor 2

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

H33 Indoor unit/Outdoor unit connected incorrectly

Priority check: 
Power supply indoor unit/outdoor unit

Possible causes:

  1. Wrong power supply (<160 V AC).
  2. Incorrect indoor or outdoor unit circuit boards
  3. (EEPROM empty or corrupt).

To check and remedy see picture.

H34 Heat sink temperature sensor in the outdoor unit

Preconditions:
2 seconds, only for multi-split inverter systems

Priority check: Heat sink temperature sensor in the outdoor unit (defective or not connected)

Possible causes:

  1. Faulty connection.
  2. Sensor fault.
  3. Faulty circuit board.

To check and rectify see figure.

H35 Condensate pump
 

Priority check: Condensate pump, condensate line

Possible causes:

  1. Float switch blocked.
  2. Connection plug of the float switch.
  3. Fall of the condensate drain or riser too high.
  4. Faulty condensate pump.

To check and rectify see figure.

H36 Suction gas temperature sensor in the outdoor unit

Preconditions:
2 seconds, only for multi-split inverter systems

Priority check:  Suction gas temperature sensor in the outdoor unit (defective or not connected)

To check and rectify see figure.

H37 Fluid temperature sensor in the outdoor unit

Preconditions:
2 seconds, only for multi-split inverter systems

Priority check: Fluid temperature sensor in the outdoor unit (defective or not connected)

To check and rectify see figure.

H38 Incorrect indoor unit/outdoor unit combination

Priority check:
Please contact one of our technicians

H39 Faulty operation of indoor unit

Preconditions: Only for multi-split inverter systems

Priority check:

  1. Wrong line connections
  2. Wrong wiring between indoor and outdoor unit

To check and rectify see figure.

H41 Incorrect wiring or piping (only CU-2E)

Preconditions: Only CU-2E15

Wiring or piping between indoor and outdoor unit incorrect.

  • At outside temperatures above 5°C, the line temperature of an indoor unit that is not supplied by the outdoor unit drops by over 20 K to 5°C or less 3 minutes after the compressor starts.
  • The suction gas temperature of an indoor unit that is not supplied with power by the outdoor unit drops by over 5 K to 5°C or less 3 minutes after the compressor starts.


Priority check: 

  • Assembly error: Lines to the indoor units interchanged

Detection of the fault

  • When starting up after switching on the power supply 3 minutes after starting the forced cooling mode.

H50: Indoor unit ventilation fan motor

Preconditions:

  1. AC-Robot only (CS-XE9 / 12EKE)
  2. 7 times in a row

Priority check:

  1. Circuit board indoor unit
  2. Ventilation fan motor
  3. Ventilation hose

To check and rectify see figure.

H51 Filter cleaner blocked

Preconditions: 2 times in a row Only AC-Robot CS-XE9 / 12EKE
Priority check: Filter cleaner (suction nozzle)

To check and rectify see figure.

 

H52 Malfunction of the filter cleaning system limit switches

Preconditions
AC-Robot only (CS-XE9 / 12EKE)

Priority check:

  1. Limit switch
  2. Indoor unit circuit board

To check and remedy see picture

 

 

 

H58 Gas sensor malfunction

Preconditions:
Unsuitable output signal from the gas sensor (5 V DC or 0 V DC).


Priority check:

  • Faulty gas sensor
  • Faulty connection
  • Faulty circuit board

Detection of the fault

  • The gas sensor emits a signal Vg of 5 or 0 V for 6 hours.

For checking and rectificationsee picture.

 

 

 

 

H97 Outdoor unit fan motor blocked

Preconditions:

  • Loss of the fan motor synchronization signal.
  • A speed greater than 2550 min-1 or less than 50 min-1 is determined.


Priority check:

  • Faulty fan motor.
  • Faulty outdoor unit circuit board

Detection of the fault

  • If it is determined 3 times within 60 minutes or 2 times within 30 minutes that the motor speed and
  • control signal were out of synchronisation 5 times in succession, this error message appears, and the device is switched off.

 

To check and rectify see figure.

 

     H98 High pressure protection indoor unit

    Preconditions: In heating mode, the heat exchanger temperature of the indoor unit is more than 60°C.
    Please note: The fault code is not displayed (TIMER LED does not flash), but it is saved in the EEPROM.


    Priority check:

    1. Dirty air filter in the indoor unit.
    2. Dust build-up on the evaporator.
    3. Air-side short circuit.
    4. Incorrect measured value of the line temperature sensor.
    5. Incorrect measured value due to faulty indoor unit circuit board.
    6. Outside temperature too high.
    7. Outdoor unit fan.
    8. Excess refrigerant.

    Detection of the fault

    In the heating mode, the line temperature of the indoor unit is more than 60°C.

    To check and rectify see figure.

     

      H99 Frost protection indoor unit

      Preconditions: Frost protection is activated if the line temperature of the indoor unit is below a certain value for too long (HKEW: 2°C).

      Possible causes:

      1. Dirty air filter in the indoor unit.
      2. Dust deposit on the evaporator.
      3. Short circuit on the air side.
      4. Incorrect measured value of the line temperature sensor.
      5. Incorrect measured value due to faulty indoor unit circuit board.

      For checking and rectification see picture.

      Meaning of the faultOutdoor unit could not receive communication signals from the indoor unit
      Preconditions      Outdoor unit cannot receive communication signals from the indoor unit
      Possible causes
      1. The power supply to the indoor unit was switched off after the first communication
      2. An interruption or short circuit occurred in the control line between the units after the initial communication was completed
      Check as a priorityCheck the power supply on the indoor and outdoor units and the control lines between the units.
      Example-
      NotesThis alarm is recognised after the initial communication is complete. For this reason, it does not occur if the connector is not connected, the terminal unit is not set, or other problems have occurred before the initial communication is completed. If the initial communication has not been completed, alarm E04 occurs.


       

      Meaning of the faultThe automatic start of the address setting is not permitted.
      PreconditionsThe automatic address setting was started when the automatic address setting was carried out on another outdoor unit in the same connection.
      Possible causes

      The automatic address setting is carried out on another outdoor unit.

      Priority checkThis alarm is not displayed on the remote control. Therefore, check the blinking on the outdoor unit circuit board.
      CorrectionThen restart the automatic address setting. Wait for the automatic address setting on the outdoor unit on which it is currently being performed to complete.
      Example
      Note
      Meaning of the faultAlarm for automatic address setting (too few units)
      Alarm conditions

      The number of indoor units was too few when the automatic address setting was carried out.

      Probable cause
      1. The number of indoor units that were set on the outdoor unit circuit board using the indoor unit quantity setting switch (S004, S005) is higher than the set number.
      2. The control lines between the units are interrupted.
      Priority check
      1. Refer to the maintenance material for the test run and check the number of indoor units set SW (S004, S005).
      2. Check the control lines between the units on the indoor and outdoor units.
      Correction

      After you adjust the quantity of the indoor unit or the wiring between the control units, carry out the automatic address setting again.

      Example
      Note2 way exchange control

      Meaning of the fault Alarm for automatic address setting (too many units)
      Alarm conditions
      • The number of indoor units was too high when the automatic address setting was carried out.
      • After the initial communication, an unrecognised unit was recognised.
      Probable cause
      • The number of indoor units that were set on the outdoor unit circuit board using the indoor unit volume setting switch (S004, S005) is less than the set number.
      • The control lines between the units are incorrectly wired.
      Check
      1. Refer to the maintenance material for the test run and check the number of indoor units set.
      2. Check the control lines between the units on the indoor and outdoor units.
      CorrectionAfter you adjust the quantity of the indoor unit or the wiring between the control units, carry out the automatic address setting again.
      Meaning of the faultNo indoor units with automatic address setting.
      PreconditionsNo indoor units were recognised with the automatic address setting
      Possible causes
      1. The control lines between the units from the outdoor unit to the indoor units have been interrupted.
      2. Serial port 1 (CN001) is not connected to the outdoor unit.
      3. The power supply is switched off on all indoor units in the system.
      Priority check
      1. Check if the control lines between the units from the outdoor unit to the indoor units are interrupted.
      2. Check whether the serial connector 1 (CN001) is disconnected from the outdoor unit.
      3. Check the power supply on the indoor units.
      Correction Reconnect the control cable between the units from the outdoor unit to the indoor unit.
      Example
      NotePosition of the CN001 serial connector to 2 pin

      Meaning of the faultOutdoor unit (INV) was unable to receive communication from another outdoor unit (constant speed).
      ConditionsAfter the first communication, communication from an outdoor unit was stopped.
      Possible causes
      1. After the first communication was completed, the control wiring between the main and secondary outdoor units was interrupted.
      2. After the first communication was completed, the power supply to the outdoor unit was turned off.
      Meaning of the faultMeaning of the error Error when setting the address of the outdoor unit (duplication).
      Preconditionswere received five times or more times through communication over the main sub-control wiring of the outdoor unit that has the same address as this unit.
      Possible causesThe device number is set incorrectly.
      Priority checkCheck the unit number again.
      Correction
      Example
      NoteRestoration after this alarm is automatic (if there is no communication with the same address for 3 minutes).
      Meaning of the faultMismatch in the quantity of outdoor units.
      PreconditionsAfter the power initialisation, the set number of outdoor units did not match the number of outdoor units for 3 minutes or more which were recognised on the main-secondary control line of the outdoor unit.
      Possible causes.
      1. The outdoor unit quantity is set incorrectly.
      2. The main-secondary control wiring of the outdoor unit is interrupted.
      Priority check.
      1. Recheck the outdoor unit quantity settings.
      2. Check the wiring of the main and sub control of the outdoor unit.
      Correction
      1. Correct the incorrect quantity setting of the outdoor unit.
      2. Repair the main-secondary control cable of the outdoor unit.
      Example
      Note

      Restoration after this alarm is automatic (if the set outdoor unit quantity matches the number of outdoor units recognised by the main-secondary control wiring of the outdoor unit).

      Meaning of the faultOutdoor unit could not receive communication from the outdoor unit (main unit)
      PreconditionsCommunication of the outdoor unit from the outdoor unit (main unit) was interrupted for at least 3 minutes.
      Possible causes
      1. After the first communication processes were completed, the main auxiliary control line of the outdoor unit was interrupted.
      2. After the first communication was completed, the RC connector was removed. (3) The power supply on the outdoor unit (main unit) is switched off.
      Priority check
      1. Check the wiring of the main and secondary control of the outdoor unit.
      2. Check the RC connections.
      3. Check power supply to the outdoor unit (main unit).
      Correction
      1. Repair the main sub control cables of the outdoor unit.
      2. Correct the RC connector.
      3. Turn on the outdoor unit (main unit).
      Meaning of the faultCommunication error between two microcomputers on the control circuit board
      Preconditions
      Possible causes

      It happens:

      • An error occurred when rewriting the microcomputer
      • If the device is switched off while rewriting the microcomputer.
      • When the wiring between the circuit board and the ROM burner is not connected.
      Priority check
      1. Rewrite the microcomputer.
      2. Switch on again
      CorrectionReplace the control circuit board
      Meaning of the faultCompressor 1 Fault in the outlet temperature sensor
      Preconditions
      1. Discharge temp. of 100°C or higher was found 20 minutes or more after the compressor stopped.
      2. Discharge temp. of 70°C or higher was found after all compressors were stopped for 60 minutes or longer.
      3. A / D step is 10 steps or less (short circuit).

       

      Possible causes
      1. Malfunction of the sensor Malfunction of the sensor element The sensor wiring is partially disconnected, which leads to increased electrical resistance. This alarm does not occur if the wiring is broken or the plug is not connected to the outdoor unit PCB.
      2. Wiring crossed or installation error The outlet temperature sensor of this compressor is connected to the outlet pipe of the other compressor. The connector for the outlet temperature sensor of the problematic compressor is connected to the PCB connector of the outdoor unit for the other compressor.
      3. PCB error of the outdoor unit
      4. The check valve on the outlet pipe of this compressor is wet.
      5. A short circuit in the air around the outdoor unit has increased the ambient temperature of the outdoor unit and the cooling effects after the compressor was switched off.
      6. There is a cause that leads to a P03, P17 or P02 alarm.
      7. Electrical noise
      Priority check

      1. Sensor malfunction and outdoor unit circuit board failure
      Problem:

          Always shows a high temperature.
          When monitoring software or other means of monitoring are used, the discharge temperature sometimes fluctuates suddenly and erratically.
          In some cases, the exact temperature may not be known even if monitoring software is used.


      Test:

          Wiggle the sensor and check if the error persists.
          Check whether the connector is partially disconnected from the circuit board.
          • An F04 alarm is not triggered if the connector is completely removed (circuit is open).
          If the cause is still uncertain, check the following to determine if a sensor or PCB error has occurred.
          Step 1:
          Connect the other compressor discharge sensor, or a discharge sensor that did not have an F04 alarm, to the connector for that compressor on the circuit board. Measure the temperature at the same point (in a place with small temperature fluctuations) and check whether there is a temperature difference.
          Difference → A circuit board or sensor error is possible.
          No difference → Circuit board and sensor are normal.
          Step 2:
          If a malfunction was detected in stage 1, connect the faulty compressor sensor to the other compressor connector on the circuit board or to the circuit board connector of a unit that did not have an F04 alarm. Measure the temperature at the same point (in a place with small temperature fluctuations) and check whether there is a temperature difference.
          Difference → Sensor error.
          No difference → PCB error.
          • It is advisable to have an outlet temperature sensor at hand at this time.

      2. Crossed wiring or installation error
      Trouble:

      Although the other compressor is operating and this compressor is stopped, the outlet temperature of the other compressor does not rise and the outlet temperature of this compressor increases.
      • The outlet temperature remains high immediately after the compressor stops. Wait some time after the compressor stops and observe.


      Although the other compressor is operating and this compressor is stopped, the outlet temperature of the other compressor does not rise and the outlet temperature of this compressor increases.
      • The outlet temperature remains high immediately after the compressor stops. Wait some time after the compressor stops and observe.

      Check:

      Check for wiring and installation errors.

      3. Leakage at the outlet pipe check valve
      Trouble:

      Although the other compressor is operating and this compressor is stopped, the outlet temperature of this compressor rises along with the temperature of the other compressor.

      4. The ambient temperature around the outdoor unit, when it is stopped, is 43°C or more.

      5. If after checking the above items the cause is still unknown, it is possible that electrical noise is the cause of the problem. It is necessary to provide a line filter or take other countermeasures against noise.

      Correction
      1.     Replace the sensor.
      2.     Replace the outdoor unit circuit board.
      3.     Carry out noise protection measures.
      4.     Repair refrigerant hose.
      5.     Adjust the amount of refrigerant.
      6.     Rectify the error.
      ExampleSensor wiring is partially cut.
      NoteThis alarm does not indicate that the sensor is not connected. To avoid overheating during operation, the outdoor units in this system do not allow a compressor to start unless the outlet temperature decreases while the compressor is stopped. If a malfunction of the sensor leads to the continuous detection of a high outlet temperature, the compressor may stop for no apparent reason. The purpose of this alarm is to make it easier to identify the problem in this case.
      Meaning of the faultCompressor 2 Fault on the outlet temperature sensor
      Preconditions
      1. Discharge temp. of 100°C or higher was found 20 minutes or more after the compressor stopped.
      2. of 70°C or higher was found after all the compressors were stopped for 60 minutes or longer.
      3. A / D step is 10 steps or less (short circuit).

       

      Possible causes
      1. Malfunction of the sensor Malfunction of the sensor element The sensor wiring is partially disconnected, which leads to increased electrical resistance. This alarm does not occur if the wiring is broken or the plug is not connected to the outdoor unit PCB.
      2. Wiring crossed or installation error The outlet temperature sensor of this compressor is connected to the outlet pipe of the other compressor. The connector for the outlet temperature sensor of the problematic compressor is connected to the PCB connector of the outdoor unit for the other compressor.
      3. PCB error of the outdoor unit
      4. The check valve on the outlet pipe of this compressor is wet.
      5. A short circuit in the air around the outdoor unit has increased the ambient temperature of the outdoor unit and the cooling effects after the compressor was switched off.
      6. There is a cause that leads to a P03, P17 or P02 alarm.
      7. Electrical noise
      Priority check

      1. Sensor malfunction and outdoor unit circuit board failure
      Problem:

          Always shows a high temperature.
          When monitoring software or other means of monitoring are used, the discharge temperature sometimes fluctuates suddenly and erratically.
          In some cases, the exact temperature may not be known even if monitoring software is used.


      Test:

          Wiggle the sensor and check if the error persists.
          Check whether the connector is partially disconnected from the circuit board.
          • An F04 alarm is not triggered if the connector is completely removed (circuit is open).
          If the cause is still uncertain, check the following to determine if a sensor or PCB error has occurred.
          Step 1:
          Connect the other compressor discharge sensor, or a discharge sensor that did not have an F04 alarm, to the connector for that compressor on the circuit board. Measure the temperature at the same point (in a place with small temperature fluctuations) and check whether there is a temperature difference.
          Difference → A circuit board or sensor error is possible.
          No difference → Circuit board and sensor are normal.
          Step 2:
          If a malfunction was detected in stage 1, connect the faulty compressor sensor to the other compressor connector on the circuit board or to the circuit board connector of a unit that did not have an F04 alarm. Measure the temperature at the same point (in a place with small temperature fluctuations) and check whether there is a temperature difference.
          Difference → Sensor error.
          No difference → PCB error.
          • It is advisable to have an outlet temperature sensor at hand at this time.

      2. Crossed wiring or installation error
      Trouble:

      Although the other compressor is operating and this compressor is stopped, the outlet temperature of the other compressor does not rise and the outlet temperature of this compressor increases.
      • The outlet temperature remains high immediately after the compressor stops. Wait some time after the compressor stops and observe.


      Although the other compressor is operating and this compressor is stopped, the outlet temperature of the other compressor does not rise and the outlet temperature of this compressor increases.
      • The outlet temperature remains high immediately after the compressor stops. Wait some time after the compressor stops and observe.

      Check:

      Check for wiring and installation errors.

      3. Leakage at the outlet pipe check valve
      Trouble:

      Although the other compressor is operating and this compressor is stopped, the outlet temperature of this compressor rises along with the temperature of the other compressor.

      4. The ambient temperature around the outdoor unit, when it is stopped, is 43°C or more.

      5. If after checking the above items the cause is still unknown, it is possible that electrical noise is the cause of the problem. It is necessary to provide a line filter or take other countermeasures against noise.

      Correction
      1.     Replace the sensor.
      2.     Replace the outdoor unit circuit board.
      3.     Carry out noise protection measures.
      4.     Repair refrigerant hose.
      5.     Adjust the amount of refrigerant.
      6.     Rectify the error.
      ExampleSensor wiring is partially cut.
      NoteThis alarm does not indicate that the sensor is not connected. To avoid overheating during operation, the outdoor units in this system do not allow a compressor to start unless the outlet temperature decreases while the compressor is stopped. If a malfunction of the sensor leads to the continuous detection of a high outlet temperature, the compressor may stop for no apparent reason. The purpose of this alarm is to make it easier to identify the problem in this case.
      Meaning of the faultGas temperature sensor fault on the outdoor heat exchanger 1
      Preconditions
      1. A / D step is 10 steps or less (short circuit).
      2. A / D step is 1014 steps or more (open circuit).
      Possible causes
      1. Sensor malfunction (including connector)
      2. PCB fault
      Priority check
      1. Measure sensor resistance. Check whether the sensor is functioning normally.
      2. Use a remote control or PC monitor to check the temperature detected by the microcomputer.
      Meaning of the faultGas temperature sensor fault on the outdoor heat exchanger 1
      Preconditions
      1. A / D step is 10 steps or less (short circuit).
      2. A / D step is 1014 steps or more (open circuit).
      Possible causes
      1. Sensor malfunction (including connector)
      2. PCB fault
      Priority check
      1. Measure sensor resistance. Check whether the sensor is functioning normally.
      2. Use a remote control or PC monitor to check the temperature detected by the microcomputer.
      Meaning of the faultProblem with the outside air temperature sensor
      Preconditions
      1. A / D step is 10 steps or less (short circuit).
      2. A / D step is 1014 steps or more (open circuit).
      Possible causes
      1. Sensor malfunction (including connector)
      2. PCB fault
      Priority check
      1. Measure sensor resistance. Check whether the sensor is functioning normally.
      2. Use a remote control or PC monitor to check the temperature detected by the microcomputer.
      Meaning of the faultCompressor intake temperature sensor defective
      Preconditions
      1. A / D step is 10 steps or less (short circuit).
      2. A / D step is 1014 steps or more (open circuit).
      Possible causes
      1. Sensor malfunction (including connector)
      2. PCB fault
      Priority check
      1. Measure sensor resistance. Check whether the sensor is functioning normally.
      2. Use a remote control or PC monitor to check the temperature detected by the microcomputer.
      Meaning of the faultHigh pressure sensor fault (abnormal increase in high pressure) (In some cases, this cannot be attributed to a malfunction of the high pressure sensor.)
      Preconditions
      Preconditions
      • High pressure SW activated even though the detected pressure was lower (3.03 MPa or less) than the high pressure SW activation pressure: Undershift
      • High pressure SW could not be activated even though the detected pressure was higher (3.43 MPa or higher)) than the high pressure SW activation pressure: Overthrust
      • The saturation temperature at the detected pressure is continuously 5°C or more below the highest internal temperature E1 for 30 minutes.
      • High pressure sensor not connected or open circuit.
      Possible causes
      1. High pressure sensor malfunction
      2. Error connecting the connector to the PCB of the outdoor unit
      3. Opening of the service valve failed
      4. Blocked hose
      5. Valve leakage
      6. Overloading
      7. Circuit board fault of the outdoor unit
      8. Electrical noise
      Priority check

      1. High pressure sensor failure

      •     Check the sensor resistance value. (Use a tester and measure the resistance between sensor # 1 and # 3)
      •     A resistance less than 10 kΩ indicates a short circuit or other problem.
      •     A resistance of 10 kΩ - 200 kΩ is normal. A resistance of more than 200 kΩ indicates a disconnection or other malfunction.
      •     Connect a pressure gauge to the high pressure outlet and check whether the value displayed by the monitoring software has changed and whether the pressure gauge pressure deviates significantly.
      •     During heating, check whether the temperature is below the highest temperature of the indoor unit E1.

          * The pressure detected by the high pressure sensor is the highest pressure in the system. Therefore, the converted saturation temperature during heating will never be lower than the internal E1 temperature. During cooling, this temperature is never lower than the outdoor unit fluid temperature.

       

      2. The service valve cannot be opened, the hoses are blocked, the valve is leaking and it is overloaded.
      In all of these cases, an alarm occurs when there are rapid pressure fluctuations and the tracking of the detected pressure is poor.

      • Check the opening/closing status of the valve.
      • Check whether the hose is blocked.    To check for blocking, disconnect the high pressure sensor from the circuit board and check that the high pressure switch is activated.
      • Check the valve for leaks and overload.
      • If a valve leak or overload occurs, refrigerant is likely to collect in the outdoor or indoor units, which leads to a sudden increase in pressure at start-up, which occurs before the refrigerant is discharged into the heat exchanger.

          * The representative valves to be checked are the fluid valves and the mechanical valves.

      3. Outdoor unit PCB failure

      • The check points are the same as in the case of a malfunction of the high pressure sensor.
        A normal PCB is needed to determine if the problem is a PCB fault or malfunction of the pressure sensor. If an abnormality in the high pressure sensor malfunction is found in the test pieces, replace the circuit board and check it again.

            The problem has been solved: Outdoor unit circuit board error
            The fault is not eliminated: High pressure sensor fault

      Correction

      1. Replace the high pressure sensor.
      Caution:
      Because a Schrader type valve is used to connect the high pressure sensor, it can be removed and replaced. However, the high pressure sensor can easily be damaged by high voltage. So take precautions regarding static electricity.

      2. Replace the circuit boards.

      3. Correct the points where problems occur in the refrigeration circuit.

          Correct areas where blockages or leaks have occurred.
          Remove refrigerant if overloaded. (Set refrigerant amount).
          ∗ Instructions regarding overloading
          Be sure to connect the pressure gauge to the high pressure outlet when checking for overload.
          While cooling:
          The following does not apply when the outside air temperature is low or when the fan speed is limited. When both compressor 1 and compressor 2 are operating and fan mode is 14 (maximum fan speed), the high pressure saturation temperature should be approximately 15°C above the outside air temperature. If it is 5°C or more above this level, it is possible that an overload has occurred.
          While heating:
          In an indoor unit, the refrigerant flow is poor (E1 temperature and outlet temperature are low), and the mechanical valve of this unit is on 3

      ExampleThis alarm can occur when the service valve is closed or when there is a valve leak (especially from the mechanical valve).
      Note
      Meaning of the fault

      Problem with the low pressure sensor

       

      Preconditions
      1. A / D step is 10 steps or less (short circuit).
      2. A / D step is 1014 steps or more (open circuit).
      Possible causes
      1. Sensor malfunction (including connector)
      2. PCB fault
      Priority check
      1. Measure sensor resistance. Check whether the sensor is functioning normally.
      2. Use a remote control or PC monitor to check the temperature detected by the microcomputer.
      Meaning of the faultCompressor 3 Fault on the outlet temperature sensor
      Preconditions
      1. Discharge temp. of 100°C or higher was found 20 minutes or more after the compressor stopped.
      2. Discharge temperature of 70°C or higher was found after all the compressors were stopped for 60 minutes or longer.
      3. A / D step is 10 steps or less (short circuit).

       

      Possible causes
      1. Malfunction of the sensor Malfunction of the sensor element The sensor wiring is partially disconnected, which leads to increased electrical resistance. This alarm does not occur if the wiring is broken or the plug is not connected to the outdoor unit PCB.
      2. Wiring crossed or installation error The outlet temperature sensor of this compressor is connected to the outlet pipe of the other compressor. The connector for the outlet temperature sensor of the problematic compressor is connected to the PCB connector of the outdoor unit for the other compressor.
      3. PCB error of the outdoor unit
      4. The check valve on the outlet pipe of this compressor is wet.
      5. A short circuit in the air around the outdoor unit has increased the ambient temperature of the outdoor unit and the cooling effects after the compressor was switched off.
      6. There is a cause that leads to a P03, P17 or P02 alarm.
      7. Electrical noise
      Priority check

      1. Sensor malfunction and outdoor unit circuit board failure
      Problem:

          Always shows a high temperature.
          When monitoring software or other means of monitoring are used, the discharge temperature sometimes fluctuates suddenly and erratically.
          In some cases, the exact temperature may not be known even if monitoring software is used.


      Test:

          Wiggle the sensor and check if the error persists.
          Check whether the connector is partially disconnected from the circuit board.
          • An F04 alarm is not triggered if the connector is completely removed (circuit is open).
          If the cause is still uncertain, check the following to determine if a sensor or PCB error has occurred.
          Step 1:
          Connect the other compressor discharge sensor, or a discharge sensor that did not have an F04 alarm, to the connector for that compressor on the circuit board. Measure the temperature at the same point (in a place with small temperature fluctuations) and check whether there is a temperature difference.
          Difference → A circuit board or sensor error is possible.
          No difference → Circuit board and sensor are normal.
          Step 2:
          If a malfunction was detected in stage 1, connect the faulty compressor sensor to the other compressor connector on the circuit board or to the circuit board connector of a unit that did not have an F04 alarm. Measure the temperature at the same point (in a place with small temperature fluctuations) and check whether there is a temperature difference.
          Difference → Sensor error.
          No difference → PCB error.
          • It is advisable to have an outlet temperature sensor at hand at this time.

      2. Crossed wiring or installation error
      Trouble:

      Although the other compressor is operating and this compressor is stopped, the outlet temperature of the other compressor does not rise and the outlet temperature of this compressor increases.
      • The outlet temperature remains high immediately after the compressor stops. Wait some time after the compressor stops and observe.


      Although the other compressor is operating and this compressor is stopped, the outlet temperature of the other compressor does not rise and the outlet temperature of this compressor increases.
      • The outlet temperature remains high immediately after the compressor stops. Wait some time after the compressor stops and observe.

      Check:

      Check for wiring and installation errors.

      3. Leakage at the outlet pipe check valve
      Trouble:

      Although the other compressor is operating and this compressor is stopped, the outlet temperature of this compressor rises along with the temperature of the other compressor.

      4. The ambient temperature around the outdoor unit, when it is stopped, is 43°C or more.

      5. If after checking the above items the cause is still unknown, it is possible that electrical noise is the cause of the problem. It is necessary to provide a line filter or take other countermeasures against noise.

      Correction
      1.     Replace the sensor.
      2.     Replace the outdoor unit circuit board.
      3.     Carry out noise protection measures.
      4.     Repair refrigerant hose.
      5.     Adjust the amount of refrigerant.
      6.     Rectify the error.
      ExampleSensor wiring is partially cut.
      NoteThis alarm does not indicate that the sensor is not connected. To avoid overheating during operation, the outdoor units in this system do not allow a compressor to start unless the outlet temperature decreases while the compressor is stopped. If a malfunction of the sensor leads to the continuous detection of a high outlet temperature, the compressor may stop for no apparent reason. The purpose of this alarm is to make it easier to identify the problem in this case.
      Meaning of the faultGas temperature sensor fault on the outdoor heat exchanger 2
      Preconditions
      1. A / D step is 10 steps or less (short circuit).
      2. A / D step is 1014 steps or more (open circuit).
      Possible causes
      1. Sensor malfunction (including connector)
      2. PCB fault
      Priority check
      1. Measure sensor resistance. Check whether the sensor is functioning normally.
      2. Use a remote control or PC monitor to check the temperature detected by the microcomputer.
      Meaning of the faultFluid temperature sensor fault on the outdoor heat exchanger 2
      Preconditions
      1. A / D step is 10 steps or less (short circuit).
      2. A / D step is 1014 steps or more (open circuit).
      Possible causes
      1. Sensor malfunction (including connector)
      2. PCB fault
      Priority check
      1. Measure sensor resistance. Check whether the sensor is functioning normally.
      2. Use a remote control or PC monitor to check the temperature detected by the microcomputer.
      Meaning of the faultDefault of the solid-state memory (EEPROM) of the outdoor unit
      preconditions
      1. Solid-state memory is not available during the power initialisation.
      2. The read values do not match after writing into the solid-state memory.
      Possible causes
      1. The memory was not inserted after the board was replaced.
      2. The lifespan of the solid-state memory has been reached.
      3. The solid-state memory is incorrectly installed (incorrect direction, bent pins, etc.).
      Priority checkCheck the solid-state memory on the circuit board.
      Meaning of the errorCT sensor of compressor 1 not connected or short-circuited
      PreconditionsThe current value at compressor 1 was 18 A or less- No current is detected, even though the compressor is in operation
      Possible causes
      1. Current transformer circuit failure (including cable break etc.)
      2. Connector of the transformer circuit removed
      3. Missing phase to which the transformer circuit is connected.
      4. This current transformer circuit is connected to the connection of the other current transformer circuit.
      5. PCB error
      6. Electrical noise
      Priority check

      1. CT circuit failure, PCB failure

      Problem: The current value during compressor operation is below the threshold.

      Check:
      • Make sure that the plug is not removed
      • Check the continuity of the transformer circuit.
      • Install a normal transformer instead of this transformer and check it. If current is detected, the circuit board can be judged to be OK.
      → Transformer is faulty
      • Check whether current flows in the phase to which the current transformer circuit is connected. Test voltage and current.

      2. Crossed wiring or installation error

      Problem: If the compressor is stopped, the actual value on the other compressor is high.
      ☆ If this type of condition occurs, the recording of the occupancy has priority.

      3. If after checking the above items the cause is still unknown, it is possible that the noise is the cause of the problem. It is necessary to connect a PC or other instrument

       

      Correction
      1. Replace the transformer circuit.
      2. Replace the outdoor unit board.
      3. Rectify the problem.
      Example
      1. The connector was not inserted after the board has been replaced.
      NoteUse a normal transformer to help determine whether the problem is a circuit board fault or a transformer fault.
      Meaning of the faultDischarge temperature sensor of compressor 1 not connected
      Preconditions
      • This alarm occurs if the temperature sensor of the discharge sensor is not inserted in the sensor holder of the tube or if the sensor itself is malfunctioning as a cut wire.
      • At an outside air temperature of 10°C or higher: An alarm is triggered if the temperature detected by the outlet sensor has changed by less than 2°C, if the compressor has been in operation for 10 minutes immediately after starting.
      • If the outside air temperature is below 10°C: An alarm is triggered if the temperature detected by the outlet sensor has changed by less than 2°C, if the compressor has been in operation for 30 minutes immediately after starting.
      Possible causes
      1. The detector for the temperature of the discharge sensor is not inserted into the sensor holder of the tube.
      2. The discharge sensor itself has a malfunction other than a cut wire.
      Priority check
      1. Make sure that sufficient heat-conductive putty is applied.
      2. Remove the discharge sensor from the sensor holder and expose the sensor to outside air for about 5 minutes. Make sure that the temperature detected by the sensor adapts to the outside air temperature. (However, the sensor cannot detect temperatures at or below 0°C.)
      Correction
      1.  Place the sensor in the holder and apply sufficient heat-conductive putty.
      2.  If the sensor is defective, replace it.
      Example
      Note

      The outlet temperature sensor is generally a sensor designed to accurately detect high temperatures. Therefore, the temperature is not accurately measured when the temperature at the measuring point is 20°C or less.

      Alarm meaning

      Low pressure switch activated

      Alarm conditions

      During A / C operation, a message is issued when the low pressure sensor installed on parts with constant low pressure continuously detects a pressure of 0.05 MPa or less or an instantaneous pressure of 0.02 MPa or less for 2 minutes. (These values represent an unusually low pressure that can damage the compressor.)
      However, the alarm does not occur in the first two cases where the procedure described above is carried out. At these times, the outdoor unit is stopped and the conditions are monitored. The alarm occurs when the above operation is performed for the fifth time. The first four times before the alarm occurs are called "pre-shutdown". If the low pressure sensor detects a pressure of 0.15 MPa or more for 3 minutes of continuous operation after the pre-shutdown occurs, the pre-shutdown counter is reset to 0.
      If the low pressure sensor continuously detects a pressure of 0.16 MPa or less for 30 minutes when the compressor is stopped, an alarm is triggered immediately (no pre-shutdown).

      Possible causes

      The vacuum in the air conditioning system has dropped to a level that no longer occurs under normal conditions.

      1. The absolute amount of gas in the system is too low (due to insufficient refrigerant charge or leakage).
      2. The refrigerant has accumulated in the circuit and has not returned to the compressor. The refrigerant has accumulated in a one-way flow location and cannot escape. The high pressure level is low, which leads to poor refrigerant flow in the circuit. (A lower high pressure leads to a smaller difference between low pressure and high pressure, which may not be sufficient to cause the refrigerant flow.)
      3. The refrigerant circuit is closed and the refrigerant has not returned to the compressor. In some cases, moisture that enters the refrigerant circuit can freeze at places with low pressure and the resulting ice can block the circuit.

      ☆ When the alarm occurs when there is sufficient refrigerant in the system ((1) and (3)), the liquid refrigerant has definitely accumulated somewhere in the system. Liquid refrigerant generally accumulates in high pressure locations. In this case, the high pressure gradually increases (but cannot increase if the location where the liquid accumulates is sufficiently large). Depending on the refrigerant saturation temperature, it can also accumulate in places with low pressure. In this case, it is unlikely that the high pressure will increase.

      Priority check:
      1. Check whether the service valve is open.
      2. Make sure that none of the valves (solenoid valves, mechanical valves) in the main refrigerant circuit are closed due to a malfunction.
      3. Make sure that no foreign matter or water has entered the refrigerant circuit.
      4. Make sure that the valve leakage on a stopped secondary unit does not result in the accumulation of refrigerant in this secondary unit
      5. Make sure that no refrigerant leaks.
      Correction
      1. If a valve fault has occurred, the valve generally needs to be replaced.
      2. If a foreign body or moisture has got into the circuit, install a strainer or a dry core (depending on the degree of the problem).
      3. If refrigerant enters the stopped secondary unit, it is likely that a valve leak has occurred. The valve must be replaced.
      Meaning of the faultFault (open circuit) on the oil sensor (connection) to compressor 1
      Preconditions

      This alarm occurs when a plug connection (pins 1 and 2 for compressor 1) is open.

      Possible causesPlug may be disconnected
      Check as a priorityCheck whether the plug is firmly connected.
      Correction
      1. Connect the plug.
      2. Correct the connection at pins 1 and 2.
      Meaning of the fault

      Overcurrent alarm for compressor 2 with constant rpm

      Preconditions

      During operation, the compressor current exceeded 12 A for at least 30 seconds. However, if this alarm goes off 4 seconds after the compressor starts it will not be recognised

      During operation, the compressor current has exceeded 14 A for at least 4 seconds. However, this alarm is not recognised 2 seconds after the compressor has started

      Possible causes
      1. Compressor failure (blocked or partially blocked)
      2. Transformer fault (including cable break)
      3. Missing power phase
      4. Low voltage
      5. PCB- Error
      Priority check

      1. Compressor failure (partially locked)

      Problem: The current value during operation considerably exceeds the value specified above.

      Test: If the current for each phase is measured with a clamp meter or similar instrument, check that the current value for all phases is not high. If MG has been switched on (caution), make sure that no compressor noises occur or that the compressor does not run with a groaning noise.

      2. CT circuit failure, PCB failure

      Check:
      • Check for bad plug contact.
      • Check the continuity of the transformer circuit.
      • Install a normal transformer instead of this transformer and check it. If current is detected, the board can be fixed.
      → Transformer is faulty
      • Check whether current flows in the phase to which the current transformer circuit is connected.
      → Test voltage and current.

      3. Missing power phase

      problem: This alarm mainly occurs when the T phase is missing. If the R phase or S phase is missing, transformer or PCB continuity problems arise. However, this may not apply in the event of a missing phase caused by a magnetic SW error.

      Check: There is a possibility of a magnetic SW error. Therefore, check the phase voltage in a location as close as possible to the compressor.

      4. Low voltage

      problem: In most cases, this occurs when another constant speed compressor (including compressors in other units) or another unit is started. This also occurs when the power cables are extremely long.

      Test: Check the voltage between the individual phases. However, if this occurs when starting other units or compressors, an oscilloscope is required.

      5. PCB error

      Test: Ensure that the current value measured with the clamp meter is not below the value measured with the PC or the remote control

      6. If after checking the above items the cause is still unknown, it is possible that noise is the cause of the problem. It is necessary to connect a PC or other instrument

      Correction:

      Replace the compressor.
      Replace the transformer circuit.
      Repair electrical circuit.
      Adjust the primary-side power. Repair the power cable.
      Replace the outdoor unit circuit board.
      Rectify the error.
      * In the event of a compressor failure, measures are likely to be taken to remedy the cause of the compressor failure (e.g., fluid jam) to prevent recurrence. Make sure that there is no cause for the compressor blocking.

      Meaning of the error

      Current alarm for compressor with constant speed and 2 locks

       

      Preconditions

      During operation, the compressor current exceeded 12 A for at least 30 seconds. However, this alarm is not recognised 4 seconds after the compressor has started

      Possible causes
      1. Compressor failure (blocked or partially blocked)
      2. Transformer fault (including cable break)
      3. Missing power phase
      4. Low voltage
      5. PCB- Error
      Priority check

      1. Compressor failure (partially locked)

      Problem: The current value during operation considerably exceeds the value specified above.

      Test: If the current for each phase is measured with a clamp meter or similar instrument, check that the current value for all phases is not high. If MG has been switched on (caution), make sure that no compressor noises occur or that the compressor does not run with a groaning noise.

      2. CT circuit failure, PCB failure

      Check:
      • Check for bad plug contact.
      • Check the continuity of the transformer circuit.
      • Install a normal transformer instead of this transformer and check it. If current is detected, the board can be fixed.
      → Transformer is faulty
      • Check whether current flows in the phase to which the current transformer circuit is connected.
      → Test voltage and current.

      3. Missing power phase

      problem: This alarm mainly occurs when the T phase is missing. If the R phase or S phase is missing, transformer or PCB continuity problems arise. However, this may not apply in the event of a missing phase caused by a magnetic SW error.

      Check: There is a possibility of a magnetic SW error. Therefore, check the phase voltage in a location as close as possible to the compressor.

      4. Low voltage

      problem: In most cases, this occurs when another constant speed compressor (including compressors in other units) or another unit is started. This also occurs when the power cables are extremely long.

      Test: Check the voltage between the individual phases. However, if this occurs when starting other units or compressors, an oscilloscope is required.

      5. PCB error

      Test: Ensure that the current value measured with the clamp meter is not below the value measured with the PC or the remote control.

      6. If after checking the above items the cause is still unknown, it is possible that noise is the cause of the problem. It is necessary to connect a PC or other instrument

      Correction:

      Replace the compressor.
      Replace the transformer circuit.
      Repair electrical circuit.
      Adjust the primary-side power. Repair the power cable.
      Replace the outdoor unit circuit board.
      Rectify the error.
      * In the event of a compressor failure, measures are likely to be taken to remedy the cause of the compressor failure (e.g., fluid jam) to prevent recurrence. Make sure that there is no cause for the compressor blocking.

      Meaning of the faultCT sensor for compressor 2 not connected or short-circuited
      ConditionsThe current value at compressor 2 was 2 A or less. No current is detected even though the compressor is in operation
      Possible causes
      1. Transformer circuit failure (including cable break etc.)
      2. Current transformer circuit connector disconnected
      3. Missing phase to which the current transformer circuit is connected
      4. This transformer circuit is connected to the connection of the other current transformer circuit.
      5. PCB error
      6. Electric noise
      Priority check

      1. CT circuit failure, PCB failure

      Problem: The current value during compressor operation is below the threshold.

      Check:
      • Make sure that the plug is not removed
      • Check the continuity of the transformer circuit.
      • Install a normal transformer instead of this transformer and check it. If current is detected, the circuit board can be judged to be OK.
      → Transformer is faulty
      • Check whether current flows in the phase to which the current transformer circuit is connected. Test voltage and current.

      2. Crossed wiring or installation error

      Problem: If the compressor is stopped, the actual value on the other compressor is high.
      ☆ If this type of condition occurs, the recording of the occupancy has priority.

      3. If after checking the above items the cause is still unknown, it is possible that the noise is the cause of the problem. It is necessary to connect a PC or other instrument

       

      Correction
      1. Replace the transformer circuit.
      2. Replace the outdoor unit board.
      3. Rectify the problem.
      Example
      1. The connector was not inserted after the board has been replaced.
      NoteUse a normal transformer to help determine whether the problem is a circuit board fault or a transformer fault.
      Meaning of the faultDischarge temperature sensor of compressor 2 not connected
      Preconditions
      • This alarm occurs if the temperature sensor of the discharge sensor is not inserted in the sensor holder of the tube or if the sensor itself is malfunctioning as a cut wire.
      • At an outside air temperature of 10°C or higher: An alarm is triggered if the temperature detected by the outlet sensor has changed by less than 2°C, if the compressor has been in operation for 10 minutes immediately after starting.
      • If the outside air temperature is below 10°C: An alarm is triggered if the temperature detected by the outlet sensor has changed by less than 2°C, if the compressor has been in operation for 30 minutes immediately after starting.
      Possible causes
      1. The detector for the temperature of the discharge sensor is not inserted into the sensor holder of the tube.
      2. The discharge sensor itself has a malfunction other than a cut wire.
      Priority check
      1. Make sure that sufficient heat-conductive putty is applied.
      2. Remove the discharge sensor from the sensor holder and expose the sensor to outside air for about 5 minutes. Make sure that the temperature detected by the sensor adapts to the outside air temperature. (However, the sensor cannot detect temperatures at or below 0°C.)
      Correction
      1.  Place the sensor in the holder and apply sufficient heat-conductive putty.
      2.  If the sensor is defective, replace it.
      Example
      Note

      The outlet temperature sensor is generally a sensor designed to accurately detect high temperatures. Therefore, the temperature is not accurately measured when the temperature at the measuring point is 20°C or less.

      Meaning of the fault

      Overcurrent alarm for compressor 3 with constant rpm

      Preconditions

      During operation, the compressor current exceeded 12 A for at least 30 seconds. However, if this alarm goes off 4 seconds after the compressor starts it will not be recognised

      During operation, the compressor current has exceeded 14 A for at least 4 seconds. However, this alarm is not recognised 2 seconds after the compressor has started

      Possible causes
      1. Compressor failure (blocked or partially blocked)
      2. Transformer fault (including cable break)
      3. Missing power phase
      4. Low voltage
      5. PCB- Error
      Priority check

      1. Compressor failure (partially locked)

      Problem: The current value during operation considerably exceeds the value specified above.

      Test: If the current for each phase is measured with a clamp meter or similar instrument, check that the current value for all phases is not high. If MG has been switched on (caution), make sure that no compressor noises occur or that the compressor does not run with a groaning noise.

      2. CT circuit failure, PCB failure

      Check:
      • Check for bad plug contact.
      • Check the continuity of the transformer circuit.
      • Install a normal transformer instead of this transformer and check it. If current is detected, the board can be fixed.
      → Transformer is faulty
      • Check whether current flows in the phase to which the current transformer circuit is connected.
      → Test voltage and current.

      3. Missing power phase

      problem: This alarm mainly occurs when the T phase is missing. If the R phase or S phase is missing, transformer or PCB continuity problems arise. However, this may not apply in the event of a missing phase caused by a magnetic SW error.

      Check: There is a possibility of a magnetic SW error. Therefore, check the phase voltage in a location as close as possible to the compressor.

      4. Low voltage

      problem: In most cases, this occurs when another constant speed compressor (including compressors in other units) or another unit is started. This also occurs when the power cables are extremely long.

      Test: Check the voltage between the individual phases. However, if this occurs when starting other units or compressors, an oscilloscope is required.

      5. PCB error

      Test: Ensure that the current value measured with the clamp meter is not below the value measured with the PC or the remote control

      6. If after checking the above items the cause is still unknown, it is possible that noise is the cause of the problem. It is necessary to connect a PC or other instrument

      Correction:

      Replace the compressor.
      Replace the transformer circuit.
      Repair electrical circuit.
      Adjust the primary-side power. Repair the power cable.
      Replace the outdoor unit circuit board.
      Rectify the error.
      * In the event of a compressor failure, measures are likely to be taken to remedy the cause of the compressor failure (e.g., fluid jam) to prevent recurrence. Make sure that there is no cause for the compressor blocking.

      Meaning of the fault

      Compressor with constant speed 3 blocks the current alarm

       

      Preconditions

      During operation, the compressor current has exceeded 14 A for at least 4 seconds. However, this alarm is not recognised 2 seconds after the compressor has started

      Possible causes
      1. Compressor failure (blocked or partially blocked)
      2. Transformer fault (including cable break)
      3. Missing power phase
      4. Low voltage
      5. PCB- Error
      Priority check

      1. Compressor failure (partially locked)

      Problem: The current value during operation considerably exceeds the value specified above.

      Test: If the current for each phase is measured with a clamp meter or similar instrument, check that the current value for all phases is not high. If MG has been switched on (caution), make sure that no compressor noises occur or that the compressor does not run with a groaning noise.

      2. CT circuit failure, PCB failure

      Check:
      • Check for bad plug contact.
      • Check the continuity of the transformer circuit.
      • Install a normal transformer instead of this transformer and check it. If current is detected, the board can be fixed.
      → Transformer is faulty
      • Check whether current flows in the phase to which the current transformer circuit is connected.
      → Test voltage and current.

      3. Missing power phase

      problem: This alarm mainly occurs when the T phase is missing. If the R phase or S phase is missing, transformer or PCB continuity problems arise. However, this may not apply in the event of a missing phase caused by a magnetic SW error.

      Check: There is a possibility of a magnetic SW error. Therefore, check the phase voltage in a location as close as possible to the compressor.

      4. Low voltage

      problem: In most cases, this occurs when another constant speed compressor (including compressors in other units) or another unit is started. This also occurs when the power cables are extremely long.

      Test: Check the voltage between the individual phases. However, if this occurs when starting other units or compressors, an oscilloscope is required.

      5. PCB error

      Test: Ensure that the current value measured with the clamp meter is not below the value measured with the PC or the remote control.

      6. If after checking the above items the cause is still unknown, it is possible that noise is the cause of the problem. It is necessary to connect a PC or other instrument

      Correction:

      Replace the compressor.
      Replace the transformer circuit.
      Repair electrical circuit.
      Adjust the primary-side power. Repair the power cable.
      Replace the outdoor unit circuit board.
      Rectify the error.
      * In the event of a compressor failure, measures are likely to be taken to remedy the cause of the compressor failure (e.g., fluid jam) to prevent recurrence. Make sure that there is no cause for the compressor blocking.

      Meaning of the faultCT sensor for compressor 3 not connected or short-circuited
      ConditionsThe current value at compressor 3 was 2 A or less. No current is detected even though the compressor is in operation
      Possible causes
      1. Transformer circuit failure (including cable break etc.)
      2. Current transformer circuit connector disconnected
      3. Missing phase to which the current transformer circuit is connected
      4. This transformer circuit is connected to the connection of the other current transformer circuit.
      5. PCB error
      6. Electric noise
      Priority check

      1. CT circuit failure, PCB failure

      Problem: The current value during compressor operation is below the threshold.

      Check:
      • Make sure that the plug is not removed
      • Check the continuity of the transformer circuit.
      • Install a normal transformer instead of this transformer and check it. If current is detected, the circuit board can be judged to be OK.
      → Transformer is faulty
      • Check whether current flows in the phase to which the current transformer circuit is connected. Test voltage and current.

      2. Crossed wiring or installation error

      Problem: If the compressor is stopped, the actual value on the other compressor is high.
      ☆ If this type of condition occurs, the recording of the occupancy has priority.

      3. If after checking the above items the cause is still unknown, it is possible that the noise is the cause of the problem. It is necessary to connect a PC or other instrument

       

      Correction
      1. Replace the transformer circuit.
      2. Replace the outdoor unit board.
      3. Rectify the problem.
      Example
      1. The connector was not inserted after the board has been replaced.
      NoteUse a normal transformer to help determine whether the problem is a circuit board fault or a transformer fault.
      Meaning of the faultDischarge temperature sensor of compressor 3 not connected
      Preconditions
      • This alarm occurs if the temperature sensor of the discharge sensor is not inserted in the sensor holder of the tube or if the sensor itself is malfunctioning as a cut wire.
      • At an outside air temperature of 10°C or higher: An alarm is triggered if the temperature detected by the outlet sensor has changed by less than 2°C, if the compressor has been in operation for 10 minutes immediately after starting.
      • If the outside air temperature is below 10°C: An alarm is triggered if the temperature detected by the outlet sensor has changed by less than 2°C, if the compressor has been in operation for 30 minutes immediately after starting.
      Possible causes
      1. The detector for the temperature of the discharge sensor is not inserted into the sensor holder of the tube.
      2. The discharge sensor itself has a malfunction other than a cut wire.
      Priority check
      1. Make sure that sufficient heat-conductive putty is applied.
      2. Remove the discharge sensor from the sensor holder and expose the sensor to outside air for about 5 minutes. Make sure that the temperature detected by the sensor adapts to the outside air temperature. (However, the sensor cannot detect temperatures at or below 0°C.)
      Correction
      1.  Place the sensor in the holder and apply sufficient heat-conductive putty.
      2.  If the sensor is defective, replace it.
      Example
      Note

      The outlet temperature sensor is generally a sensor designed to accurately detect high temperatures. Therefore, the temperature is not accurately measured when the temperature at the measuring point is 20°C or less.

      Meaning of the faultFault (open circuit) on the oil sensor (connection) to compressor 2
      Preconditions

      This alarm occurs when a plug connection (pins 4 and 5 for compressor 2) is open.

      Possible causesPlug may be disconnected
      Priority checkCheck whether the plug is firmly connected.
      Correction
      1. Connect the plug.
      2. Correct the connection at pins 4 and 5.
      Meaning of the faultFault (open circuit) on the oil sensor (connection) to compressor 3
      Preconditions

      This alarm occurs when a plug connection (pins 7 and 8 for compressor 3) is open.

      Possible causesPlug may be disconnected
      Priority checkCheck whether the plug is firmly connected.
      Correction
      1. Connect the plug.
      2. Correct the connection at pins 7 and 8.
      Meaning of the faultHIC malfunction detector
      PreconditionsThis alarm occurs when the microcomputer detects an error signal (indicating an abnormal HIC temperature or other problems) from the HIC.
      The HIC assesses the current and the temperature and outputs the error signal. In general, this indicates problems with the HIC itself.
      Possible causesOvercurrent in the HIC circuit and the resulting abnormal warming caused by a HIC error
      Priority check

      Check the power and connection cables. If the wiring and connections are normal, use a tester to measure the resistance between the HIC performance of the compressor (HIC +) and ground (HIC–).
      In the event of a short circuit, there is a HIC fault.

      CorrectionIf a HIC fault is found, replace the circuit board.
      Example
      NoteSwitch The power supply and check the continuity of HIC + and HIC– on the HIC board.
      Meaning of the faultDouble system address outdoors
      Possible causesIncorrect address settings of the outdoor system
      Priority check

      Check the settings of the system address again

      CorrectionCorrect the system address settings.
      Example
      NoteRestoration after this alarm is automatic (if the communication containing the same address as this device is not received 3 minutes after detection).
      Meaning of the faultCapacity of the outdoor unit not set
      PreconditionsThe capacity of the outdoor unit has not been set or the setting is not permitted by the system.
      Possible causesThis alarm occurs because the capacity has not been set.
      Priority checkCheck if code 81 is incorrect. Use the remote control to maintain the outdoor unit and set it properly.
      * After changing the setting, make sure that you reset both the indoor and outdoor voltage.
      Correction
      1. Connect the connector.
      2. Correct the connection on pins 4 and 5.
      Example
      NoteThe remote control for servicing the outdoor unit is required to set the capacity in the EEPROM of the outdoor unit.
      Meaning of the faultOutdoor unit model not matching
      PreconditionsThis alarm occurs when a device other than a refrigerant R410A model is connected.
      Probable cause
      Possible causes
      1. A unit with R407C refrigerant or a model R22 unit was accidentally connected.
      2. The connected unit is correct, but the refrigerant type setting in the outdoor unit's EEPROM (item code 80) is incorrect.
      Priority check
      1. Check the refrigerant type on the connected device.
      2. Use the remote control to service the outdoor unit and check the refrigerant type with item number 80. If the setting is incorrect, change it in R410A.
      Correction
      Example
      NoteThe remote controller for maintenance of the outdoor unit is required to set the refrigerant type in the EEPROM of the outdoor unit.
      Meaning of the fault4-way valve actuation error
      PreconditionsWhile heating (Comp. ON), the highest detected temperature on a heat exchanger of the outdoor unit (EXG 1, EXG 2, EXL 1 or EXL 2) was 20°C or more above the outside air temperature (air temp.) continuously for 5 minutes or longer or the recorded intake temperature (SCT) was 20°C or more above the outside air temperature continuously for 5 minutes or longer.
      Possible causes
      1. A unit with R407C refrigerant or a model R22 unit was accidentally connected. The 4-way valve connector (20S CN022) has been disconnected from the control board.
      2. The 4-way valve circuit is blocked (fault).
      Priority check
      1. Check the 4-way valve connector (20S CN022).
      2. If the connector is OK, check the 4-way valve wiring and PCB circuit.
      CorrectionIf the connector is normal, correct or replace the problem locations.
      Alarm meaning

      The thermal protection of the compressor is activated. (trigger only and no alarm)

      Preconditions

      If the current is not detected for 4 seconds after the compressor is switched on.

      Possible causes

      Activation state of the thermal protection of the compressor (the voltage between phase L and N is more than 260 V or less than 160 V)

      Priority check
      1. Check the compressor at constant speed.
      2. Check the transformer
      Correction
      • Switch off the compressor at constant speed for 60 minutes and cool the thermostat.
      • Replace defective parts with new ones.
      Meaning of the faultProblems with compressor 1 outlet temperature
      PreconditionsThe temperature is 106°C or more and there was a stop before triggering. The alarm occurs when the stop occurs more than once before triggering. However, the flow counter is cleared if the compressor runs continuously for a certain period of time.
      Possible causes
      1. Blockage of the liquid valve capillaries
      2. Insufficient amount of refrigerant (including problems due to insufficient initial charge and gas leakage)
      3. Blocking of low-pressure parts through the penetration of foreign bodies (moisture, scale, etc.)
      4. Crossing (hose or circuit board connector) with the other compressor thermistor
      5. Malfunction of the expansion valve
      6. Accumulation of refrigerant on stopped outdoor units
      7. Sensor for compressor discharge defective
      8. PCB- Error (A / D conversion error)
      9. Electrical noise
      Priority check

      1. Capillary blockage

      problem: The compressor outlet temperature does not drop even if the liquid valve is switched on.

      If the fluid valve is in operation and the liquid valve is switched on, check whether the secondary side of the liquid capillaries is cold.

      2. Too little refrigerant

      problem: The fluid effect is bad

      Test: Check whether or not the superheat temperature drops when the mechanical valve of the evaporator is opened to 300 pulses or more (after checking for foreign matter).

      3. Contamination by foreign bodies

      Problem: The effectiveness of the fluid valve is poor

      Control: Make sure that there is no difference in condensation or frost conditions between the primary and secondary tubes of the strainer.

      4. Crossed thermistor

      problem: The outlet temperature of the other compressor is high, although only this compressor is in operation. When the liquid valve turns on, the outlet temperature of the other compressor drops.

      5. Accumulation of refrigerant in stopped outdoor units

      Problem:
      • The system is OK when all outdoor units are in operation. However, when a certain outdoor unit is stopped, symptoms of insufficient gas appear.
      • Condensation or frost are visible up to the top of the battery of the stopped outdoor unit.
      • After stopping an outdoor unit, there is a sound when refrigerant flows into an outdoor unit that has been stopped for a long time.
      • If an outdoor unit starts after a long rest, the start is accompanied by strong vibrations.

      Check:
      Representative parts are the liquid capillaries (the secondary side of the capillaries is cool during cooling operation), the mechanical valve, the mechanical valve bypass check valve (refrigerant flow noise can be heard and stops when the liquid valve is closed) and the hot gas defrost valve (if the secondary valve side is still hot after a long period of time, be careful not to confuse the transferred heat with a valve failure.)
      Ice grows on the lower parts of some heat exchangers for outdoor units, but not on others.
      • Because this problem can also occur with outdoor units with a high operating speed under conditions with insufficient gas, caution should be exercised.

      6. Sensor defective

      Test:
      • This alarm is likely to occur when the wiring is partially broken. (It is difficult to identify even if the continuity is checked.) The detected discharge temperature is high.
      • Although such conditions rarely occur, a P02 alarm is likely when the detected discharge temperature is low.
      • Replace the sensor with another discharge sensor and compare the temperature conditions.

      7. If the cause is not known after checking the above points, it is possible that the electrical noise is the cause of the fault.

      Correction
      1. Replace the sensor.
      2. Replace the outdoor unit circuit board.
      3. Correct the problem areas.
      Example

      All probable causes

      Note

      Works continuously for a set period of time. Shows 2.5 minutes or more for an inverter unit and 30 seconds or more for a constant speed compressor

      Meaning of the faultHigh pressure switch activated.
      Preconditions

      The operation of the electronic circuit in the high pressure switch can short-circuit the connection depending on the pressure. The terminal is short-circuited at a pressure of 3.3 MPa or more. As soon as the connection is short-circuited, it remains in this state until the pressure drops below 2.6 MPa.

      Possible causes
      1. Failure of the check valve in the pressure pipe of the compressor.
      2. The service valve is closed.
      3. Blockage of the outdoor heat exchanger when cooling down.
      4. An air short in the outdoor unit during cooling.
      5. Failure of the outdoor fan during cooling.
      6. Blockage of the air filter in the indoor unit during heating.
      7. Air short in the indoor unit during heating.
      8. Failure of the indoor fan when heating.
      9. Blockage of the refrigerant circuit.
      10. Failure of the mechanical valve.
      11. Failure of the solenoid valve set.
      12. Refrigerant has been over filled.
      13. Failure of the high pressure switch.
      Check as a priority.

      1. Make sure that the high pressure switch connector is correctly connected.
      2. When the high pressure switch is properly connected, connect a high pressure manometer to the high pressure outlet and monitor the pressure during operation to check the pressure when the high pressure switch is activated. The check valve is likely to fail if the pressure is less than 3.3 MPa. The following describes tests that must be carried out at high pressure.
      3. While cooling down, check if the heat exchanger of the outdoor unit is clogged. Remove any material that prevents ventilation.
      4. While cooling, check whether there is an air short in the outdoor unit. The system works normally unless the temperature around the outdoor unit is too high.
      5. While cooling down, check whether the outdoor fan is defective. Check whether the screws securing the fan are loose and that the fan connector on the outdoor unit PCB is properly connected.
      6. While heating, check whether the air filters in the indoor unit are blocked. If it is blocked, clean the filter.
      7. While heating, check whether there is an air short in the indoor unit. The system works normally unless the temperature around the outdoor unit is too high.
      8. While heating, check whether the indoor fan is defective.
      9. Check if the refrigerant circuit is blocked. Check that all service valves are closed. Check whether the welds are blocked.
      10. Check whether the mechanical valve is defective. Check if the mechanical valves cause rattling when resetting the power supply. Since the mechanical valve in the indoor unit is in a place that makes it difficult to test by ear, use an electrical device for testing. Check that the mechanical valve connector pin on the board outputs 4V. Also check that the coil resistance of the mechanical valve is several tens Ω.
      11. Check whether the solenoid valve set is defective. Removing a coil that is switched on results in a clicking sound. Removing a coil that is not switched on also does not result in such a sound.
      12. Check whether the refrigerant has been over charged. Too much refrigerant has been charged when the subcooling temperature of the condenser is 15°C or higher.

      CorrectionReplace damaged components and correct the amount of refrigerant charged
      Meaning of the faultReverse phase (or missing phase) detected.
      PreconditionsThis alarm occurs when an inverted phase or a missing phase is detected in phases L1-L2-L3-N.
      Possible causesPhase reversal or missing phase in phases L1-L2-L3-N.
      Priority checkThe wiring on the power terminal plate.
      CorrectionChange phases and plug in again. Check if the result is in order
      Meaning of the faultO2 sensor operation
      Preconditions
      1. A fault is evaluated if the outdoor unit receives the O2 alarm signal generated by the indoor unit.
      2. If the EEPROM setting of the indoor unit (item code 0B) is set to 0001, the EXCT input short-circuited.
      Possible causes

      Priority check

      1. System configuration
               1-1 Is an O2 sensor being used?
               If yes, see 3-1.
               If no, see 2-1.
             
            2-1 Internal EEPROM setting
               Is the EEPROM setting, item code 0B, on the internal control card set to 0001?
               If yes, see 3-1 after changing.
               If no, see 4-1.
             
            3-1 EXCT wiring
               Is the EXCT socket (cable) short-circuited?
               If yes, change the wiring.
               If no, see 4-1.
                                                              
            Internal control card
               4-1 Is the alarm triggered when the EXCT connector (cable) is disconnected and the power supply is reset?
               If yes, see 4-3.
               If not, see 4-2.

        4-2 See what happens because there is no error.

               4-3 Internal control card defective → replace card

       

       

      Meaning of the faultOvercurrent alarm for compressor 1 (INV).
      Conditions

      This alarm occurs when a current fault or a current detection fault occurs (when a fault judgment current is detected in the primary or secondary current or if an instantaneous secondary current of 18 A * or higher is detected).
      * Changed to output errors due to current regardless of the frequency of the inverter.
        In addition to this there are 6 HP and 10 HP compressors.

          If more than the overcurrent values in the primary and secondary current specified in the table have been determined.

          Primary secondary
            6 HP compressors 18 A 18 A
          10 HP Compressors 21 A 21 A

          If more than the current values specified in the table are immediately detected in the secondary current.

          Second
            6 HP compressors 28 A
          10 HP compressors 36 A

      Possible causes

      There is a strong possibility of a compressor failure. An alarm for current detection problems occurs when it is determined that no current is flowing after the start (DCCT is damaged). In this case, the cause is a DCCT error.

      Priority checkCheck the power and connector wiring.
      CorrectionIt is possible to solve this problem by limiting the maximum frequency.

       

       

      Meaning of the faultProblems with compressor 2 outlet temperature
      PreconditionsThe temperature is 106°C or more and there was a stop before triggering. The alarm occurs when the stop occurs more than once before triggering. However, the flow counter is cleared if the compressor runs continuously for a certain period of time.
      Possible causes
      1. Blockage of the liquid valve capillaries
      2. Insufficient amount of refrigerant (including problems due to insufficient initial charge and gas leakage)
      3. Blocking of low-pressure parts through the penetration of foreign bodies (moisture, scale, etc.)
      4. Crossing (hose or circuit board connector) with the other compressor thermistor
      5. Malfunction of the expansion valve
      6. Accumulation of refrigerant on stopped outdoor units
      7. Sensor for compressor discharge defective
      8. PCB- Error (A / D conversion error)
      9. Electrical noise
      Priority check

      1. Capillary blockage

      problem: The compressor outlet temperature does not drop even if the liquid valve is switched on.

      If the fluid valve is in operation and the liquid valve is switched on, check whether the secondary side of the liquid capillaries is cold.

      2. Too little refrigerant

      problem: The fluid effect is bad

      Test: Check whether or not the superheat temperature drops when the mechanical valve of the evaporator is opened to 300 pulses or more (after checking for foreign matter).

      3. Contamination by foreign bodies

      Problem: The effectiveness of the fluid valve is poor

      Control: Make sure that there is no difference in condensation or frost conditions between the primary and secondary tubes of the strainer.

      4. Crossed thermistor

      problem: The outlet temperature of the other compressor is high, although only this compressor is in operation. When the liquid valve turns on, the outlet temperature of the other compressor drops.

      5. Accumulation of refrigerant in stopped outdoor units

      Problem:
      • The system is OK when all outdoor units are in operation. However, when a certain outdoor unit is stopped, symptoms of insufficient gas appear.
      • Condensation or frost are visible up to the top of the battery of the stopped outdoor unit.
      • After stopping an outdoor unit, there is a sound when refrigerant flows into an outdoor unit that has been stopped for a long time.
      • If an outdoor unit starts after a long rest, the start is accompanied by strong vibrations.

      Check:
      Representative parts are the liquid capillaries (the secondary side of the capillaries is cool during cooling operation), the mechanical valve, the mechanical valve bypass check valve (refrigerant flow noise can be heard and stops when the liquid valve is closed) and the hot gas defrost valve (if the secondary valve side is still hot after a long period of time, be careful not to confuse the transferred heat with a valve failure.)
      Ice grows on the lower parts of some heat exchangers for outdoor units, but not on others.
      • Because this problem can also occur with outdoor units with a high operating speed under conditions with insufficient gas, caution should be exercised.

      6. Sensor defective

      Test:
      • This alarm is likely to occur when the wiring is partially broken. (It is difficult to identify even if the continuity is checked.) The detected discharge temperature is high.
      • Although such conditions rarely occur, a P02 alarm is likely when the detected discharge temperature is low.
      • Replace the sensor with another discharge sensor and compare the temperature conditions.

      7. If the cause is not known after checking the above points, it is possible that the electrical noise is the cause of the fault.

      Correction
      1. Replace the sensor.
      2. Replace the outdoor unit circuit board.
      3. Correct the problem areas.
      Example

      All probable causes

      Note

      Works continuously for a set period of time. Shows 2.5 minutes or more for an inverter unit and 30 seconds or more for a constant speed compressor

      Meaning of the faultProblems with compressor 3 outlet temperature
      PreconditionsThe temperature is 106°C or more and there was a stop before triggering. The alarm occurs when the stop occurs more than once before triggering. However, the flow counter is cleared if the compressor runs continuously for a certain period of time.
      Possible causes
      1. Blockage of the liquid valve capillaries
      2. Insufficient amount of refrigerant (including problems due to insufficient initial charge and gas leakage)
      3. Blocking of low-pressure parts through the penetration of foreign bodies (moisture, scale, etc.)
      4. Crossing (hose or circuit board connector) with the other compressor thermistor
      5. Malfunction of the expansion valve
      6. Accumulation of refrigerant on stopped outdoor units
      7. Sensor for compressor discharge defective
      8. PCB- Error (A / D conversion error)
      9. Electrical noise
      Priority check

      1. Capillary blockage

      problem: The compressor outlet temperature does not drop even if the liquid valve is switched on.

      If the fluid valve is in operation and the liquid valve is switched on, check whether the secondary side of the liquid capillaries is cold.

      2. Too little refrigerant

      problem: The fluid effect is bad

      Test: Check whether or not the superheat temperature drops when the mechanical valve of the evaporator is opened to 300 pulses or more (after checking for foreign matter).

      3. Contamination by foreign bodies

      Problem: The effectiveness of the fluid valve is poor

      Control: Make sure that there is no difference in condensation or frost conditions between the primary and secondary tubes of the strainer.

      4. Crossed thermistor

      problem: The outlet temperature of the other compressor is high, although only this compressor is in operation. When the liquid valve turns on, the outlet temperature of the other compressor drops.

      5. Accumulation of refrigerant in stopped outdoor units

      Problem:
      • The system is OK when all outdoor units are in operation. However, when a certain outdoor unit is stopped, symptoms of insufficient gas appear.
      • Condensation or frost are visible up to the top of the battery of the stopped outdoor unit.
      • After stopping an outdoor unit, there is a sound when refrigerant flows into an outdoor unit that has been stopped for a long time.
      • If an outdoor unit starts after a long rest, the start is accompanied by strong vibrations.

      Check:
      Representative parts are the liquid capillaries (the secondary side of the capillaries is cool during cooling operation), the mechanical valve, the mechanical valve bypass check valve (refrigerant flow noise can be heard and stops when the liquid valve is closed) and the hot gas defrost valve (if the secondary valve side is still hot after a long period of time, be careful not to confuse the transferred heat with a valve failure.)
      Ice grows on the lower parts of some heat exchangers for outdoor units, but not on others.
      • Because this problem can also occur with outdoor units with a high operating speed under conditions with insufficient gas, caution should be exercised.

      6. Sensor defective

      Test:
      • This alarm is likely to occur when the wiring is partially broken. (It is difficult to identify even if the continuity is checked.) The detected discharge temperature is high.
      • Although such conditions rarely occur, a P02 alarm is likely when the detected discharge temperature is low.
      • Replace the sensor with another discharge sensor and compare the temperature conditions.

      7. If the cause is not known after checking the above points, it is possible that the electrical noise is the cause of the fault.

      Correction
      1. Replace the sensor.
      2. Replace the outdoor unit circuit board.
      3. Correct the problem areas.
      Example

      All probable causes

      Note

      Works continuously for a set period of time. Shows 2.5 minutes or more for an inverter unit and 30 seconds or more for a constant speed compressor

      Meaning of the faultHigh load fault
      PreconditionsThe high pressure rise is not quick, but the alarm occurs if the power does not reach the expected time downwards.
      Possible causes
      1. Forgot to open the valve
      2. Malfunction of the mechanical valve
      3. Idle speed away from the outside fan
      Priority checkCheck the valve, the mechanical valve and the outside fan.
      Meaning of the faultFan motor problems
      PreconditionsFan motor start fault, fan motor Hall IC input fault.
      Possible causesHall IC input circuit fault or on Fan HIC failure.
      Priority inspection

      Check fan motor wiring, Hall IC wiring, and connector connections.
      If the wiring and connections are OK, check that the Hall IC input circuit capacitor is firmly soldered to the control board of the outdoor unit. Also use a tester and measure the resistance between fan HIC power (HIC +) and ground (HIC–).
      In the event of a short circuit, there is a HIC fault.

      Correction

      If the fan does not start, the following corrections can be effective.

      •     If there is a fan HIC error or a circuit error, replace the board.
      •     If the fan motor is blocked, replace the fan motor.
      Example
      NoteSwitch off the power supply and check the continuity of "+" and "-" on the fan circuit board.
      Meaning of the faultInverter compressor has phase or blocking alarm.
      PreconditionsThis alarm can occur at start-up and occurs if a missing phase or lock is detected and if a DCCT error occurs.
      Possible causesAlarm Generally, this alarm occurs when the refrigerant pressure equalisation is uneven at startup or when the inverter compressor locks up, there is no phase in the inverter compressor wiring, or a DCCT error occurs. This can be interpreted as a start-up problem that is not caused by HIC.
      Priority checkCheck the power and connector cabling.
      CorrectionDCCT error (replace board) or compressor error
      Example
      NoteUse a tester to measure the voltage between the DCCT output on the back of the PCB and the earth. If the voltage is not within 2 - 3 V, the DCCT is malfunctioning.

      Retrieving the fault code with the cable remote control

       

      Kabelfernbedienung

      If a fault occurs, CHECK flashes in the display (see figure above).

      check01When the CHECK button is pressed, an error code from F15 to F44 now appears in the timer field. The air conditioner number appears instead of the set temperature:

      check02While the fault is displayed, press the TIMER SET button. The fault code is now replaced by an additional code that provides more detailed information on the previously mentioned fault:

       

       

       

       

       

      Please note:
      For single operation, "01" appears as the air conditioner number. In the case of a group set-up, however, a different number can appear. By pressing the "A / C No." the air conditioner number can be called up.

      Display of previous fault codes

      If the CHECK display is not flashing, press the CHECK button for 5 seconds to display the last or second last fault. You can toggle between the last and second last fault by pressing the TIMER UPup or DOWN down buttons.
      Display the last fault code: 1F15 - 1F44
      Display the second last fault code: 2F15 - 2F44
      The additional code is also called up in this case with the TIMER SET button.
      Press the CHECK button again to return to the normal display.

      check03Press for 5 seconds
      the CHECK button:

       

       

      check04Press for additional codes
      the TIMER SET button


       

      Retrieving the fault code with the infrared remote control

      Infrarotbedienung

       

      When a fault occurs, the TIMER LED flashes on the infrared receiver. To query the fault code, the list of fault codes must be run through with the remote control until the indoor unit beeps to indicate that the corresponding fault code has been found. To do this, proceed as follows:

       

      Press the button for 5 seconds until "- -: -"  appears on the display.
      1. press the button again. "F 00:00" appears.
      2. The keys are used to scroll through the digits of the first fault code from "F 0" to "F 9”.
        As soon as the number of the first digit matches that of the fault code, a beep sounds in the indoor unit.
      3. The search for the first digit is now completed by pressing the SET button and the cursor jumps to the second digit.
      4. Steps 3 to 4 are repeated for the second and third digits.

      The search for the fault code is completed as soon as a beep sounds at the fourth digit after pressing the buttons or in the indoor unit. The complete fault code can now be read from the display.

      F15-01 Float switch

      Description of the faultFloat switch
      Preconditions for fault messageTriggered by an open float switch.
      Possible

      Cassettes:

      1. Condensate pump blocked or no slope.
      2. Faulty condensate pump (CN-DRMTR).
      3. Float switch not connected (CN-TH2, Connections 1 and 2).
      4. Float switch defective (blocked in open position).
      5. Faulty indoor unit circuit board.

      Ceiling and duct units:

      1. Bridge on CN-TH2, connections 1 and 2 open.
      2. Faulty indoor unit circuit board.
      Detection of the fault
      • The float switch is open for longer than 5 minutes.
      • The float switch opens twice within 20 minutes while the device is operating in cooling or dehumidifying mode.

      F16-01 Louvre switch (ceiling-mounted units)

      Fault descriptionLouvre switch (ceiling-mounted units)
      Preconditions for fault messageThe fault occurs when the louvre limit switch does not output any switching signals, even though the louvre motor is activated.
      Possible causes
      1. Louvres blocked, louvre shaft broken. Louvre motor not connected or cable defective.
      2. Louvre motor defective.
      3. Louvre limit switch not connected or defective
      4. Faulty indoor unit circuit board
      Detection of the fault

      See above under “Preconditions for fault message".

      F17-02 DC fan

      Fault descriptionDC fan motor
      Preconditions for fault message
      • Loss of fan motor synchronisation signal.
      • Detection of rpm >2250 min-1 or <50 min-1.
      Possible causes
      1. Defective fan motor.
      2. Faulty motor connection on the circuit board.
      3. Fan motor blocked.
      Faulty indoor unit circuit board.
    1. Fault detection
    2. Within 25 seconds of DC fan motor start

      F20-01 Indoor unit intake temperature sensor (room temperature sensor)

      Fault descriptionIndoor unit intake temperature sensor (room temperature sensor)
      Preconditions for fault message
      • At temperature of <-46 °C was detected for 5 seconds.
      • A temperature> 80 ° C is detected within 20 minutes after the start of operation and during operation of the indoor unit fan for 120 seconds.
      Possible causes
      1. Faulty connection
        (CN-TH2, connections 3 and 4).a
      2. Sensor fault (short-circuited or open).
      3. Faulty circuit board.
      Detection of the fault

      See above under “Preconditions for the fault message".



      F20-02 Remote control temperature sensor

      Fault descriptionRemote control temperature sensor
      Preconditions for fault message
      • Instead of the intake temperature sensor in the indoor unit the room temperature sensor was switched to the temperature sensor of the cable remote control.
      • A temperature of <-20 ° C or> 80 ° C is detected for 5 seconds.
      Possible causes

      Sensor error in the cable remote control.

      Detection of the fault

      See above under “Preconditions for fault message".

      F21-01 Indoor unit heat exchanger temperature sensor

      Fault descriptionIndoor unit heat exchanger temperature sensor
      Preconditions for fault message
      • This air conditioner is in use
        (except defrost mode).
      • A temperature <-38°C or > 130°C is detected for 5 seconds.
      Possible causes
      1. Faulty connection
        (CN-TH1, connections 3 and 4).a
      2. Sensor fault (short-circuited or open).
      3. Faulty circuit board.
      Detection of the fault

      See above under “Preconditions for the fault message".

      F26-01Remote data transmission

      Description of faultRemote data transmission
      Preconditions for fault message

      No response from the remote control for 3 minutes.

      Possible causes
      1. Incorrect wiring of the remote control.
      2. Faulty connection CN-REM (cable remote control) or CN-DISP
        (Infrared receiver).
      3. Incorrect configuration when using two cable remote controls.
      4. Cable remote control is set to SLAVE although there is no MASTER.
      5. Faulty indoor unit circuit board.
      6. Faulty circuit board of the cable or infrared remote control.
      7. External faults.
      Detection of the fault

      See above under “Preconditions for the fault message”.

      F27-01 Connection between indoor and outdoor unit disconnected

      Fault descriptionConnection between indoor and outdoor unit disconnected
      Preconditions for fault message

      If the communication between the indoor and the outdoor unit cannot be established for 3 minutes or is interrupted, this fault code appears.

      Possible causes
      1. Communication line between indoor and outdoor unit.
      2. Defective outdoor unit circuit board.
      3. Defective indoor unit circuit board.
      Detection of the fault

      3 minutes after the connection has been disconnected.


      F27-05 Connection between indoor and outdoor unit

      Fault descriptionConnection between indoor and outdoor unit
      Preconditions for fault message

      A faulty connection is detected twice within 5 seconds

      Possible causes
      1. Incorrect wiring between indoor and outdoor unit.
      2. Incorrect data transmission due to interference via the power supply.
      3. Incorrect indoor unit circuit board.
      4. Incorrect outdoor unit circuit board.
      Detection of the fault

      Immediately after the problem occurs.

      F30-01 System problem
       

      Description of faultSystem problem
      Preconditions for fault message

      The performance of the indoor unit (or the sum of the indoor units) does not match the outdoor unit (the total output of the connected indoor units is below the minimum power limit or above the maximum power limit of the outdoor unit).

      Possible causes

      Too many indoor units or indoor unit (s) of incorrect power connected.

      Detection of the fault

      Immediate

       

      F30-02 Phase open or reversed

       

      Description of the faultPhase open or reversed
      Preconditions for fault message

      The system detects a phase that does not exist or is inverted.

      Possible causes
      1. Faulty power supply.
      2. Choke coil.
      3. Faulty outdoor unit circuit board.
      4. Faulty relay.
      5. Faulty PTC-Sensor.

       

      F31-01 Suction pressure shutdown

      Description of the faultSuction pressure shutdown
      Preconditions for fault message
      • In cooling mode, the line temperature sensor of the indoor unit activates the suction pressure protection.
      • In heating mode, the line temperature sensor of the outdoor unit activates the suction pressure protection.
      • In cooling and heating mode, the low pressure switch activates the suction pressure protection.
      Possible causes
      1. Service valve closed.
      2. Lack of refrigerant.
      3. Dirty air filter in the indoor unit.
      4. Dust deposits on the evaporator/condenser.
      5. Air-side short circuit in indoor/outdoor unit.
      6. Wrong measured value of the line temperature sensor in indoor/outdoor unit.
      7. Incorrect measured value due to faulty indoor unit circuit board.

       


      F31-02 High pressure shutdown

      Description of the faultHigh pressure shutdown
      Preconditions for fault messageThe heat exchanger temperature is above the limit, which indicates an increase in high pressure.
      Possible causes
      1. Service valve closed.
      2. Heat emission blocked.
      3. Dirty air filter in the indoor unit.
      4. Faulty outdoor unit circuit board.
      5. Faulty wiring between indoor and outdoor unit.
      Detection of the faultThe heat exchanger temperature must be above the limit three times within 30 minutes for one minute each.

       

      F32-06 Switch valve

      Description of the faultSwitch valve
      Preconditions for fault messageWhen the compressor is running, the indoor unit heat exchanger is too cold (<5°C) for 5 minutes in heating mode (except when defrosting) or too warm in cooling mode (>45°C).
      Possible causes
      1. Indoor unit line temperature sensor.
      2. Faulty switch valve.
      3. Faulty outdoor unit circuit board.
      Detection of the faultThe above preconditions are met three times within 30 minutes.

       

      F32-08 Freezing of the indoor unit heat exchanger

      Description of the faultFreezing of the indoor unit heat exchanger
      Preconditions for fault messageThe temperature of the indoor unit heat exchanger is below a certain value for a certain period.
      Possible causes
      1. Air flow too low.
      2. Lack of refrigerant.
      3. Faulty indoor unit line temperature sensor.
      4. Outside temperature too low.
      5. Faulty indoor unit circuit board.

       

      F32-09 Inverter protection (DC overcurrent

      Inverter protection (DC overcurrent)Preconditions)
      for fault messageInverter DC overcurrent signals are detected during start-up and in cooling and heating mode.
      Possible causes
      1. Faulty outdoor unit circuit board.
      2. Compressor defective.
      3. Incorrect cable size.
      4. Airflow too low.
      Detection of the fault
      • DC overcurrent signals are detected 7 times within 30 minutes, within 30 seconds of compressor start-up.
      • DC overcurrent signals are detected 3 times within 30 minutes 30 seconds after the compressor has started.

       

      F32-10 Refrigeration problem

      Description of the faultRefrigeration problem
      Preconditions for fault message

      One of the following conditions must be met within seven minutes of the compressor starting up in cooling mode:

      • Heat exchanger temperature of the indoor unit when the compressor starts - 3 K <current
        Heat exchanger temperature of the indoor unit for 5 minutes.
      • Air intake temperature - 3 K <current heat exchanger temperature of the indoor unit for 5 minutes.
      Possible causes
      1. Service valve closed.
      2. Significant lack of refrigerant.
      3. Faulty indoor unit circuit board.
      4. Faulty indoor unit line temperature sensor.
      5. Faulty suction temperature sensor in the indoor unit.
      6. Faulty expansion valve.
      Detection of the faultSee under “Preconditions for fault message”.

      F32-03 Inverter protection (low DC voltage)

      Description of the faultInverter protection (low DC protection)
      Preconditions for fault messageDC voltage <180 V in 40 ms after tightening RY_AC (RY_PWR).
      Possible causes
      1. Supply voltage too low.
      2. Sudden drop in voltage.
      Detection of the faultImmediate.


       

      F32-04 Overheating protection of the power transistor (IPM)

      Description of the faultOverheating protection of the power transistor (IPM)
      Preconditions for fault messageElevated temperature of the power transistor module (IPM) (5 Sec. > 95°C).
      Possible causes
      1. Insufficient heat output from the outdoor unit.
      2. Excess refrigerant.
      3. Faulty power transistor.
      4. Service valve closed.
      5. Faulty outdoor unit circuit board.
      Detection of the fault4 occurrences within 30 minutes.


       

      F32-05 Compressor overcurrent protection

      Description of the faultCompressor overcurrent protection
      Preconditions for fault messageThe current consumption is exceptionally high during compressor operation.
      Possible causes
      1. Insufficient heat emission in the outdoor or indoor unit.
      2. Service valve closed.
      3. Faulty power transistor.
      4. Faulty compressor.
      5. Faulty outdoor unit circuit board.
      Detection of the fault3 occurrences within 30 minutes.

       

      F32-06 Hot gas temperature protection

      Description of the faultHot gas temperature protection
      Preconditions for fault messageIn cooling or heating mode, the hot gas temperature exceeds 110°C, the compressor is switched off. If it falls below 105°C, the compressor starts again after 3 minutes.
      Possible causes
      1. Insufficient heat emission in the outdoor or indoor unit.
      2. Lack of refrigerant.
      3. Faulty hot gas temperature sensor.
      4. Faulty outdoor unit board.
      Detection of the fault3 occurrences within 60 minutes.


       

      F32-08 Inverter protection (reactive current compensation)

      Description of the faultInverter protection (reactive current compensation)
      Preconditions for fault messageIncorrect signals in the reactive current compensation circuit (PFC circuit).
      Possible causes
      1. Faulty power supply.
      2. Faulty outdoor unit circuit board.
      3. Faulty compressor.
      Detection of the faultThe problem has existed for three minutes.


        

      F32-09 Inverter protection (DC overcurrent

      Description of the faultInverter protection (DC overcurrent)
      Preconditions for fault messageInverter DC overcurrent signals are detected during start-up and in cooling and heating mode.
      Possible causes
      1. Faulty outdoor unit circuit board.
      2. Compressor defective.
      3. Incorrect cable size.
      4. Airflow too low.
      Detection of the fault
      • DC overcurrent signals are detected 7 times within 30 minutes, within 30 seconds of compressor start-up.
      • DC overcurrent signals are detected 3 times within 30 minutes, 30 seconds after the compressor has started.

       

      F32-10 Incorrect compressor speed

      Description of the faultIncorrect compressor speed
      Preconditions for fault messageThe compressor speed does not correspond to the speed signal.
      Possible causes
      1. Faulty outdoor unit circuit board.
      2. Faulty indoor unit circuit board.
      3. Faulty wiring between indoor and outdoor unit.
      4. Wiring between indoor and outdoor unit disconnected.
      5. Incorrect data transmission due to interference via the power supply.
      Detection of the fault4 occurrences within 20 minutes.

      F35 DC fan motor blocked.

      Priority check:
      DC fan motor
      No obvious fault: Please contact one of our technicians

      F40-01 Outside temperature sensor

      Description of the faultOutside temperature sensor
      Preconditions for fault messageA temperature of <-33.4°C or > 124°C is determined for 5 seconds.
      Possible causes
      1. Faulty connection (CN-TH1, connections 1 and 2).
      2. Sensor error (short-circuited or open).
      3. Faulty circuit board.

       

      F40-11 Compressor suction gas temperature sensor

      Description of the faultCompressor suction gas temperature sensor
      Preconditions for fault messageA temperature of <-50.5°C or > 103.7°C is detected for 5 seconds.
      Possible causes
      1. Faulty connection (CN-TH2, connection 3 and 4).
      2. Sensor error (short-circuited or open).
      3. Faulty circuit board.

       

      F40-21 Compressor suction gas temperature sensor

      Description of the faultCompressor suction gas temperature sensor
      Preconditions for fault messageA temperature of <-50.5°C or > 103.7°C is detected for 5 seconds.
      Possible causes
      1. Faulty connection (CN-TH1, connection 3 and 4).
      2. Sensor error (short-circuited or open).
      3. Faulty circuit board.

       

      F40-31 Defrost temperature sensor

      Description of the faultDefrost temperature sensor
      Preconditions for fault messageA temperature of <-50.5°C or > 103.7°C is detected for 5 seconds.
      Possible causes
      1. Faulty connection (CN-TH2, connection 1 and 2).
      2. Sensor error (short-circuited or open).
      3. Faulty circuit board.

       

      F40-51 Compressor hot gas temperature sensor

      Description of the faultCompressor hot gas temperature sensor
      Preconditions for fault messageWith the compressor running (except start-up), a temperature <-4.5°C or > 201.8°C is detected for 5 seconds.
      Possible causes
      1. Faulty connection (CN-DIS 1 and 3).
      2. Sensor error (short-circuited or open).
      3. Faulty circuit board.

       

       

       

       

       

       

      F41 -02 High pressure switch open

       

      Description of faultHigh pressure switch open
      Preconditions for fault messageThe high pressure switch is open for one minute while the compressor is stopped.
      Possible causes
      1. Faulty high pressure switch (break contact).
      2. Faulty outdoor unit circuit board.
      3. High pressure switch connection cable, connection CN-PSW1.

       

      F41 - 12  Low pressure switch -open
       

      Description of the faultLow pressure switch (Not Inverter)
      Preconditions for fault messageThe low pressure switch is open for one minute while the compressor is stopped.
      Possible causes
      1. Faulty low pressure switch (make contact).
      2. Faulty outdoor unit circuit board.
      3. Low pressure switch connection cable, connection.

       

       

      F42 Transformer

      Description of the faultTransformer in outdoor unit is open
      Preconditions for fault messageThe power consumption is too low for 60 seconds after the compressor starts.
      Possible causes
      1. lack of refrigerant.
      2. Transformer defective.
      3. Outdoor unit circuit board defective.
      4. Compressor defective (low compression).
      5. Large fluctuations in the voltage supply due to unusually high loads in the same circuit as the outdoor unit
      Detection of the fault

      1 minute after compressor start:

      • Frequency <30 Hz: under 1 A
      • Frequency > 30 Hz: under 2 A

      F44: Inverter protection

      Description of the faultInverter protection (Power transistor module temperature sensor)
      Preconditions for fault messageThe temperature sensor in the circuit of the power transistor module determines an elevated temperature.
      Possible causes:Faulty outdoor unit circuit board.

      Overview of fault codes

      blinktblinksleuchtetshinesAUSOUT
      Cable remote controlDiagnostic LEDs
      on outdoor unit circuit board
      DiagnosticsPriority check
       Code Additional-
      Code
      302 (2)303 (3)304 (4)305 (5)306 (6)307 (7)308
      (8)
      309 (–)
      F15-01AUSblinktblinktblinktblinktAUS*1
      *2
      *1Float switchCondensate pump, condensate line, indoor unit connections CN-TH2.
      F16-01AUSAUSAUSAUSAUSblinkt*1
      *2
      *1Louvre switchLouvre motor, connection to cover, louvre motor connections to indoor unit board.
      F17-02blinktblinktAUSAUSAUSblinkt*1
      *2
      *1DC fan motorDC fan motor in the indoor unit or connection terminals.
      F20-01AUSAUSAUSblinktAUSblinkt*1
      *2
      *1Indoor unit intake temperature sensorSensor connection cable, connection CN-TH2.
      -02blinktAUSAUSblinktAUSblinkt*1
      *2
      *1Remote control temperature sensor.Remote control sensor.
      F21-01AUSblinktAUSblinktAUSblinkt*1
      *2
      *1Indoor unit heat exchanger temperature sensorSensor connection cable, connection CN-TH1.
      F26-01AUSAUSblinktAUSblinktblinkt*1
      *2
      *1Remote control data transmissionRemote control cable and connection.
      F27-01AUSblinktblinktAUSblinktblinkt*1
      *2
      *1Connection between indoor and outdoor unit disconnectedConnection cable or connections or power supply of indoor and outdoor unit (indoor unit).
      -05blinktblinktblinktAUSblinktblinkt*1
      *2
      *1Connection between indoor and outdoor unit disconnectedConnection cable or connections or power supply of indoor and outdoor unit (indoor unit).
      F27-01blinktAUSblinktAUSblinktblinktAUSAUSConnection between indoor and outdoor unit separatedConnection cable or connections or power supply for indoor and outdoor unit (outdoor unit).
      -05AUSAUSAUSAUSblinktAUSAUSAUSConnection between indoor and outdoor unit separatedConnection cable or connections or power supply for indoor and outdoor unit (outdoor unit).
      F30-01AUSAUSAUSAUSAUSblinktAUSAUSSystem problem (inverter unit)The total output of the connected indoor units is too small or too large. Check the total output and quantity of indoor units.
      -01AUSAUSAUSblinktblinktAUSAUSAUSSystem problem (not inverter units)
      -02AUSAUSblinktAUSAUSblinktAUSAUSPhase open or reversed (inverter units)Check connections at the supply terminals or swap two phases.
      -02AUSAUSblinktblinktblinktAUSAUSAUSPhase open or reversed (not inverter units)
      F31-01AUSblinktAUSAUSAUSAUSAUSAUSSuction pressure shutdownToo little refrigerant.
      -02blinktAUSAUSAUSAUSAUSAUSAUSHigh pressure shutdownCheck cooling system.
      -06AUSAUSblinktblinktAUSAUSAUSAUSDiverter valveCheck diverter valve or cable.
      -08AUSblinktAUSAUSAUSblinktAUSAUSFreezing (cooling model)Check cooling system.
      -09AUSblinktblinktblinktAUSAUSAUSAUSRefrigerant leakageCheck cooling system.
      -10AUSblinktblinktAUSblinktAUSAUSAUSRefrigeration problemToo little refrigerant or valve closed.
      F32-03AUSAUSblinktAUSblinktAUSAUSAUSInverter protection (Low DC voltage)Check power supply.
      -04blinktblinktAUSAUSblinktAUSAUSAUSPower transistor overheating protection (IPM)Power transistor or motherboard failure.
      -04blinktblinktAUSAUSAUSAUSAUSAUSCompressor overcurrent protectionPhase open or compressor blocked.
      -06blinktblinktAUSblinktAUSAUSAUSAUSHot gas temperature protectionToo little refrigerant.
      -08blinktAUSblinktblinktAUSAUSAUSAUSInverter protection (reactive current compensation)PFC circuit fault.
      -09blinktAUSAUSAUSblinktAUSAUSAUSInverter protection (DC overcurrent)Power transistor module fault or compressor blocked.
      -10blinktblinktblinktblinktAUSAUSAUSAUSIncorrect compressor rpmPower transistor module fault or compressor blocked.
      F35-02AUSblinktAUSAUSblinktAUSAUSAUSDC fan motorDC fan motor blocked.
      F40-01AUSAUSblinktAUSAUSAUSAUSAUSOutside temperature sensorSensor connection, connection CN-TH1.
      -11AUSAUSAUSblinktAUSAUSAUSAUSCompressor suction gas temperature sensorSuction temperature sensor (SUC T. TEMP), connection CN-TH2 or valve (closed).
      -21blinktAUSblinktAUSAUSAUSAUSAUSTemperature sensor on outdoor unit heat exchanger outletConnection cable of the temperature sensor at the heat exchanger outlet in the outdoor unit (COND TEMP), connection CN-TH1.
      -31blinktblinktblinktAUSAUSAUSAUSAUSDefrost temperature sensorDefrost temperature sensor connection cable (PIPE TEMP), connection CN-TH2.
      -51AUSblinktblinktAUSAUSAUSAUSAUSCompressor hot gas temperature sensorHot gas temperature connection cable (DIS T. TEMP), Connection CN-DIS.
      F41-02blinktblinktAUSblinktblinktAUSAUSAUSHigh pressure switch open (not inverter)High pressure switch connection cable, Connection CN-PSW1.
      -02blinktblinktAUSAUSAUSblinktAUSAUSHigh pressure switch open (Inverter)
      -12blinktAUSblinktblinktblinktAUSAUSAUSLow pressure sensorLow pressure sensor connection cable, Connection.
      F42-11AUSblinktAUSblinktAUSAUSAUSAUSTransformer openFault outdoor unit circuit board (interference filter) or connection ACN2.
      F44-01blinktAUSAUSblinktAUSAUSAUSAUSInverter protection (power transistor module temperature sensor)Power transistor or motherboard failure.

      Note:
      The LED numbers in front of the bracket apply to inverter devices, in the bracket to non inverter devices.

      LED*1: In the case of inverter dual systems,
           LEDs 08 ad 09 indicate in which
           of the two indoor units the problem
           shows:

       

      LED*2: In the case of non inverter dual systems,
           the 8 LED shows in which
           of the two indoor units the problem
           occurs:

      Additional notes:

      • LED-Position If the green LED 01 lights up, this indicates that the microprocessor on the board is working properly.
        If this LED is off or flashes irregularly, check the power supply, switch the unit off and on again.
      • If there is more than one error between the indoor and outdoor unit, it is possible that the display on the remote control and the LED display on the outdoor unit circuit board do not match.  In this case both locations are to be checked.
       
      ATTENTION
      For safety reasons and to prevent damage to components, the power supply must always be disconnected before a component is disconnected and reconnected.

       

      Self-diagnosis

      If a fault occurs in the indoor or outdoor unit, the system is switched off. The module that caused the malfunction is shown on the LCD display of the remote control and on the LED display on the electronic circuit boards. Before the device can be put into operation again, the fault must be eliminated using the table on page 91. The flashing CHECK indicator (in the timer display field) on the remote control indicates a fault, and the fault diagnosis LEDs on the circuit boards indicate where the fault occurred. After pressing the CHECK button on the remote control, the corresponding fault code is displayed on the remote control in the field of the timer display. The last three fault codes can be called up.

      Important:
      If the green LED 1 on the indoor and outdoor unit boards is lit, this means that the board's microprocessor is working properly. If this LED is not lit or flashes irregularly, the power supply should first be checked and the device switched off and on again.

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      Error code E03: The remote control does not recognise a communication signal from the remote control

      Possible causes:

      • No remote control connected to the indoor unit.
      • Remote control defective.
      • Remote control connection to the indoor unit is faulty.

       

      Error code E01: The remote control detects an error signal from the indoor unit

      Possible causes:
      The address of the indoor unit was incorrectly controlled by the unwanted remote control of the indoor unit.
      Error receiving the serial communication signal. (Signal from the main indoor unit with group control)
      Example: The automatic address is not complete.

      Error code E02: The remote control detects an error signal from the indoor unit

      Possible causes:
      Serial communication signal transmission error

      Error code E04: The indoor unit detects an error signal from the main outdoor unit

      Possible causes:
      Error receiving the serial communication signal. When the power is turned on, the number of connected indoor units does not match the set number. (Except if the R.C. address is "0".)

       

      Error code E06: Outdoor unit receives errors from indoor unit

      Alarm conditions:
      Outdoor unit could not receive serial communication signals from indoor unit

      Possible cause:
      The power supply to the indoor unit was turned off after the first communication
      An interruption or short circuit occurred in the control line between the units after the initial communication was completed

      Location:
      Check the power supply on the indoor and outdoor units and the control lines between the units

      Notes:
      This alarm is recognised after the initial communication is completed. For this reason, it does not occur if the serial port is not connected, the terminal unit is not set, or other problems have occurred before the initial communication is completed. If the initial communication has not been completed, alarm E04 occurs

       

      Error code E12: Do not allow automatic address setting to start

      Alarm conditions:
      The automatic address setting started when the automatic address setting was performed on another outdoor unit in the same connection

      Possible cause:
      The automatic address setting is carried out on another outdoor unit

      Location:
      This alarm is not shown on the remote control. Therefore, check the blinking on the outdoor unit circuit board.

      Correction
      Wait for the automatic address setting on the outdoor unit, on which it is being performed, to finish. Then restart the automatic address setting

      Error code E15: Automatic address setting alarm (too few units)


      Alarm conditions:
      The number of indoor units was too small when the automatic address setting was carried out

      Possible causes:
      The number of indoor units set with the indoor unit quantity setting SW (SW3, SW4) on the circuit board of the outdoor unit is too high
      The control lines between the indoor units have been disconnected.

      Location:
      Refer to the maintenance material for the test run and check the quantity setting of the indoor unit SW (SW3, SW4).
      Check the control lines between the units on the indoor and outdoor units

      Correction:
      Perform the automatic address setting again after correcting the quantity setting of the indoor unit or the wiring between the units

      Notes:
      3WAY switch position