Fault codes FS devices
Retrieving the fault code with the cable remote control
If a fault occurs, CHECK flashes in the display (see figure above).
When 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:
While 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 UP
or 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.
Press for 5 seconds
the CHECK button:
Press for additional codes
the TIMER SET button
Retrieving the fault code with the infrared remote control
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 again. "F 00:00" appears.
- 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. - The search for the first digit is now completed by pressing the SET button and the cursor jumps to the second digit.
- 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 fault | Float switch |
| Preconditions for fault message | Triggered by an open float switch. |
| Possible | Cassettes:
Ceiling and duct units:
|
| Detection of the fault |
|
F16-01 Louvre switch (ceiling-mounted units)
| Fault description | Louvre switch (ceiling-mounted units) |
| Preconditions for fault message | The fault occurs when the louvre limit switch does not output any switching signals, even though the louvre motor is activated. |
| Possible causes |
|
| Detection of the fault | See above under “Preconditions for fault message". |
F17-02 DC fan
| Fault description | DC fan motor |
| Preconditions for fault message |
|
| Possible causes |
|
| Faulty indoor unit circuit board. | Within 25 seconds of DC fan motor start |
F20-01 Indoor unit intake temperature sensor (room temperature sensor)
| Fault description | Indoor unit intake temperature sensor (room temperature sensor) |
| Preconditions for fault message |
|
| Possible causes |
|
| Detection of the fault | See above under “Preconditions for the fault message". |
F20-02 Remote control temperature sensor
| Fault description | Remote control temperature sensor |
| Preconditions for fault message |
|
| 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 description | Indoor unit heat exchanger temperature sensor |
| Preconditions for fault message |
|
| Possible causes |
|
| Detection of the fault | See above under “Preconditions for the fault message". |
F26-01Remote data transmission
| Description of fault | Remote data transmission |
| Preconditions for fault message | No response from the remote control for 3 minutes. |
| Possible causes |
|
| Detection of the fault | See above under “Preconditions for the fault message”. |
F27-01 Connection between indoor and outdoor unit disconnected
| Fault description | Connection 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 |
|
| Detection of the fault | 3 minutes after the connection has been disconnected. |
F27-05 Connection between indoor and outdoor unit
| Fault description | Connection between indoor and outdoor unit |
| Preconditions for fault message | A faulty connection is detected twice within 5 seconds |
| Possible causes |
|
| Detection of the fault | Immediately after the problem occurs. |
F30-01 System problem
| Description of fault | System 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 fault | Phase open or reversed |
| Preconditions for fault message | The system detects a phase that does not exist or is inverted. |
| Possible causes |
|
F31-01 Suction pressure shutdown
| Description of the fault | Suction pressure shutdown |
| Preconditions for fault message |
|
| Possible causes |
|
F31-02 High pressure shutdown
| Description of the fault | High pressure shutdown |
| Preconditions for fault message | The heat exchanger temperature is above the limit, which indicates an increase in high pressure. |
| Possible causes |
|
| Detection of the fault | The heat exchanger temperature must be above the limit three times within 30 minutes for one minute each. |
F32-06 Switch valve
| Description of the fault | Switch valve |
| Preconditions for fault message | When 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 |
|
| Detection of the fault | The above preconditions are met three times within 30 minutes. |
F32-08 Freezing of the indoor unit heat exchanger
| Description of the fault | Freezing of the indoor unit heat exchanger |
| Preconditions for fault message | The temperature of the indoor unit heat exchanger is below a certain value for a certain period. |
| Possible causes |
|
F32-09 Inverter protection (DC overcurrent
| Inverter protection (DC overcurrent) | Preconditions) |
| for fault message | Inverter DC overcurrent signals are detected during start-up and in cooling and heating mode. |
| Possible causes |
|
| Detection of the fault |
|
F32-10 Refrigeration problem
| Description of the fault | Refrigeration problem |
| Preconditions for fault message | One of the following conditions must be met within seven minutes of the compressor starting up in cooling mode:
|
| Possible causes |
|
| Detection of the fault | See under “Preconditions for fault message”. |
F32-03 Inverter protection (low DC voltage)
| Description of the fault | Inverter protection (low DC protection) |
| Preconditions for fault message | DC voltage <180 V in 40 ms after tightening RY_AC (RY_PWR). |
| Possible causes |
|
| Detection of the fault | Immediate. |
F32-04 Overheating protection of the power transistor (IPM)
| Description of the fault | Overheating protection of the power transistor (IPM) |
| Preconditions for fault message | Elevated temperature of the power transistor module (IPM) (5 Sec. > 95°C). |
| Possible causes |
|
| Detection of the fault | 4 occurrences within 30 minutes. |
F32-05 Compressor overcurrent protection
| Description of the fault | Compressor overcurrent protection |
| Preconditions for fault message | The current consumption is exceptionally high during compressor operation. |
| Possible causes |
|
| Detection of the fault | 3 occurrences within 30 minutes. |
F32-06 Hot gas temperature protection
| Description of the fault | Hot gas temperature protection |
| Preconditions for fault message | In 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 |
|
| Detection of the fault | 3 occurrences within 60 minutes. |
F32-08 Inverter protection (reactive current compensation)
| Description of the fault | Inverter protection (reactive current compensation) |
| Preconditions for fault message | Incorrect signals in the reactive current compensation circuit (PFC circuit). |
| Possible causes |
|
| Detection of the fault | The problem has existed for three minutes. |
F32-09 Inverter protection (DC overcurrent
| Description of the fault | Inverter protection (DC overcurrent) |
| Preconditions for fault message | Inverter DC overcurrent signals are detected during start-up and in cooling and heating mode. |
| Possible causes |
|
| Detection of the fault |
|
F32-10 Incorrect compressor speed
| Description of the fault | Incorrect compressor speed |
| Preconditions for fault message | The compressor speed does not correspond to the speed signal. |
| Possible causes |
|
| Detection of the fault | 4 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 fault | Outside temperature sensor |
| Preconditions for fault message | A temperature of <-33.4°C or > 124°C is determined for 5 seconds. |
| Possible causes |
|
F40-11 Compressor suction gas temperature sensor
| Description of the fault | Compressor suction gas temperature sensor |
| Preconditions for fault message | A temperature of <-50.5°C or > 103.7°C is detected for 5 seconds. |
| Possible causes |
|
F40-21 Compressor suction gas temperature sensor
| Description of the fault | Compressor suction gas temperature sensor |
| Preconditions for fault message | A temperature of <-50.5°C or > 103.7°C is detected for 5 seconds. |
| Possible causes |
|
F40-31 Defrost temperature sensor
| Description of the fault | Defrost temperature sensor |
| Preconditions for fault message | A temperature of <-50.5°C or > 103.7°C is detected for 5 seconds. |
| Possible causes |
|
F40-51 Compressor hot gas temperature sensor
| Description of the fault | Compressor hot gas temperature sensor |
| Preconditions for fault message | With the compressor running (except start-up), a temperature <-4.5°C or > 201.8°C is detected for 5 seconds. |
| Possible causes |
|
F41 -02 High pressure switch open
| Description of fault | High pressure switch open |
| Preconditions for fault message | The high pressure switch is open for one minute while the compressor is stopped. |
| Possible causes |
|
F41 - 12 Low pressure switch -open
| Description of the fault | Low pressure switch (Not Inverter) |
| Preconditions for fault message | The low pressure switch is open for one minute while the compressor is stopped. |
| Possible causes |
|
F42 Transformer
| Description of the fault | Transformer in outdoor unit is open |
| Preconditions for fault message | The power consumption is too low for 60 seconds after the compressor starts. |
| Possible causes |
|
| Detection of the fault | 1 minute after compressor start:
|
F44: Inverter protection
| Description of the fault | Inverter protection (Power transistor module temperature sensor) |
| Preconditions for fault message | The 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
 | blinks |  | shines |  | OUT |
| Cable remote control | Diagnostic LEDs on outdoor unit circuit board | Diagnostics | Priority check | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Code | Additional- Code | 302 (2) | 303 (3) | 304 (4) | 305 (5) | 306 (6) | 307 (7) | 308 (8) | 309 (–) | ||
| F15 | -01 | | | | | | | *1 *2 | *1 | Float switch | Condensate pump, condensate line, indoor unit connections CN-TH2. |
| F16 | -01 | | | | | | | *1 *2 | *1 | Louvre switch | Louvre motor, connection to cover, louvre motor connections to indoor unit board. |
| F17 | -02 | | | | | | | *1 *2 | *1 | DC fan motor | DC fan motor in the indoor unit or connection terminals. |
| F20 | -01 | | | | | | | *1 *2 | *1 | Indoor unit intake temperature sensor | Sensor connection cable, connection CN-TH2. |
| -02 | | | | | | | *1 *2 | *1 | Remote control temperature sensor. | Remote control sensor. | |
| F21 | -01 | | | | | | | *1 *2 | *1 | Indoor unit heat exchanger temperature sensor | Sensor connection cable, connection CN-TH1. |
| F26 | -01 | | | | | | | *1 *2 | *1 | Remote control data transmission | Remote control cable and connection. |
| F27 | -01 | | | | | | | *1 *2 | *1 | Connection between indoor and outdoor unit disconnected | Connection cable or connections or power supply of indoor and outdoor unit (indoor unit). |
| -05 | | | | | | | *1 *2 | *1 | Connection between indoor and outdoor unit disconnected | Connection cable or connections or power supply of indoor and outdoor unit (indoor unit). | |
| F27 | -01 | | | | | | | | | Connection between indoor and outdoor unit separated | Connection cable or connections or power supply for indoor and outdoor unit (outdoor unit). |
| -05 | | | | | | | | | Connection between indoor and outdoor unit separated | Connection cable or connections or power supply for indoor and outdoor unit (outdoor unit). | |
| F30 | -01 | | | | | | | | | System 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. |
| -01 | | | | | | | | | System problem (not inverter units) | ||
| -02 | | | | | | | | | Phase open or reversed (inverter units) | Check connections at the supply terminals or swap two phases. | |
| -02 | | | | | | | | | Phase open or reversed (not inverter units) | ||
| F31 | -01 | | | | | | | | | Suction pressure shutdown | Too little refrigerant. |
| -02 | | | | | | | | | High pressure shutdown | Check cooling system. | |
| -06 | | | | | | | | | Diverter valve | Check diverter valve or cable. | |
| -08 | | | | | | | | | Freezing (cooling model) | Check cooling system. | |
| -09 | | | | | | | | | Refrigerant leakage | Check cooling system. | |
| -10 | | | | | | | | | Refrigeration problem | Too little refrigerant or valve closed. | |
| F32 | -03 | | | | | | | | | Inverter protection (Low DC voltage) | Check power supply. |
| -04 | | | | | | | | | Power transistor overheating protection (IPM) | Power transistor or motherboard failure. | |
| -04 | | | | | | | | | Compressor overcurrent protection | Phase open or compressor blocked. | |
| -06 | | | | | | | | | Hot gas temperature protection | Too little refrigerant. | |
| -08 | | | | | | | | | Inverter protection (reactive current compensation) | PFC circuit fault. | |
| -09 | | | | | | | | | Inverter protection (DC overcurrent) | Power transistor module fault or compressor blocked. | |
| -10 | | | | | | | | | Incorrect compressor rpm | Power transistor module fault or compressor blocked. | |
| F35 | -02 | | | | | | | | | DC fan motor | DC fan motor blocked. |
| F40 | -01 | | | | | | | | | Outside temperature sensor | Sensor connection, connection CN-TH1. |
| -11 | | | | | | | | | Compressor suction gas temperature sensor | Suction temperature sensor (SUC T. TEMP), connection CN-TH2 or valve (closed). | |
| -21 | | | | | | | | | Temperature sensor on outdoor unit heat exchanger outlet | Connection cable of the temperature sensor at the heat exchanger outlet in the outdoor unit (COND TEMP), connection CN-TH1. | |
| -31 | | | | | | | | | Defrost temperature sensor | Defrost temperature sensor connection cable (PIPE TEMP), connection CN-TH2. | |
| -51 | | | | | | | | | Compressor hot gas temperature sensor | Hot gas temperature connection cable (DIS T. TEMP), Connection CN-DIS. | |
| F41 | -02 | | | | | | | | | High pressure switch open (not inverter) | High pressure switch connection cable, Connection CN-PSW1. |
| -02 | | | | | | | | | High pressure switch open (Inverter) | ||
| -12 | | | | | | | | | Low pressure sensor | Low pressure sensor connection cable, Connection. | |
| F42 | -11 | | | | | | | | | Transformer open | Fault outdoor unit circuit board (interference filter) or connection ACN2. |
| F44 | -01 | | | | | | | | | Inverter 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.
*1: In the case of inverter dual systems,
LEDs 08 ad 09 indicate in which
of the two indoor units the problem
shows:
*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:
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.
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.