Daikin Heat Pump Troubleshooting

The table below contains the lists of possible breakdowns and problems in Daikin heat pump work. You may determine the reason of your heat pump not working, addressing to the symptoms or error codes in the tables.

In case of your Daikin heat pump not cooling, you may see different descriptions and reasons of the same problem – for example, heat pump fan not spinning properly, or power supply problem. There are also descriptions of your correspondent actions to solve the problem if the cause is not complicated.

If the actions and measures described do not solve the situation, call the specialist to repair your heat pump.

Daikin FTXATX-K Series Heat Pump Troubleshooting

SymptomCheck ItemMeasures
The unit does not operate.Check the power supply.Check if the rated voltage is supplied.
Check the type of the indoor unit.Check if the indoor unit type is compatible with the outdoor unit.
Check the outdoor temperature.Heating operation is not available when the outdoor temperature is 18°CWB or higher and cooling operation is not available when the outdoor temperature is below -10°CDB.
Diagnose with remote controller indication.
Check the remote controller addresses.Check if address settings for the remote controller and indoor unit are correct.
Operation sometimes stops.Check the power supply.A power failure of 2 to 10 cycles stops air conditioner operation. (Operation lamp OFF)
Check the outdoor temperature.Heating operation is not available when the outdoor temperature is 18°CWB or higher, and cooling operation is not available when the outdoor temperature is below -10°CDB.
Diagnose with remote controller indication.
The unit operates but does not cool, or does not heat.Check for wiring and piping errors in the connection between the indoor unit and outdoor unit.
Check for thermistor detection errors.Check if the thermistor is mounted securely.
Check for faulty operation of the electronic expansion valve.Set the unit to cooling operation, and check the temperature of the liquid pipe to see if the electronic expansion valve works.
Diagnose with remote controller indication.
Diagnose by service port pressure and operating current.Check for refrigerant shortage.
Large operating noise and vibrationsCheck the output voltage of the power module.
Check the power module.
Check the installation condition.Check if the required spaces for installation (specified in the installation manual) are provided.

Daikin EKHBRD011ADV1 Heat Pump Troubleshooting

Error codeFailure causeCorrective action
F3Discharge temperature errorContact your local dealer.
J3Discharge thermistor error (R6T)• Check wiring connections.
J5R134a liquid thermistor error
JAR134a high pressure sensor error (B1PH)
JCR134a low pressure sensor error (B1PL)
L1Compressor inverter PCB error
L4Fin thermistor error
L5Compressor inverter PCB error
L8Compressor inverter PCB error
L9Compressor inverter PCB error
LCInverter communication problem
LHConverter error
P1Main compressor PCB error
PJBad combination inverter components
U2Power supply error
U4QA transmission problem
U5Remote controller error
UAType connection problem• Wait till initialization between outdoor unit and indoor unit is finished (after power ON, wait at least 12 minutes).
UCAddress duplication error
UFTransmission problem with outdoor unit
UFQA wiring problem
UHAddress error

Daikin EHYKOMB33AA Heat Pump Troubleshooting

Possible causesCorrective action
Gas tap is closed.Open the gas tap.
Air in the gas tap.Remove air from the gas pipe.
Gas supply pressure too low.Contact the gas supply company.
No ignition.Replace the ignition electrode.
No spark. Ignition unit on gas valve faulty.- Check the cabling.
• Check the spark plug cap.
• Replace the ignition unit.
Gas/air adjustment NOT correctly set.Check the adjustment.
Fan faulty.- Check the wiring.
• Check the fuse. If necessary, replace the fan.
Fan dirty.Clean the fan.
Gas valve faulty.• Replace the gas valve.
• Re-adjust the gas valve
Gas supply pressure too high.The house pressure switch may be faulty. Contact the gas company.
Incorrect ignition gap.• Replace the ignition pin.
• Check the ignition electrode gap.
Gas/air adjustment NOT correctly set.Check the setting.
Weak spark.Check the ignition gap.
Replace the ignition electrode.
Replace the ignition unit on the gas valve.

Daikin ALTHERMA Heat Pump Troubleshooting

Possible ProblemsCorrective action
Heat pump errorCheck the user interface.
Communication problem with the heat pump.Make sure the communication cable is properly installed.
Incorrect heat pump settings.Check the settings in the heat pump manual.
The service display displays V, the gas boiler is switched off.Switch on the gas boiler
No current (24 V)• Check the wiring.
• Check the connector X4.
The burner does NOT fire on space heating: sensor S1 or S2 faulty.Replace sensor S1 or S2.
At high rpm, the power has fallen by more than 5%.• Check the appliance and flue system for fouling.
• Clean the appliance and flue system.
Weather-dependent setpoint setting is incorrect.Check the setting on the user interface and adjust if necessary.
Temperature is too low.Increase the space heating temperature.
No circulation in the installation.Check whether there is circulation. At least 2 or 3 radiators MUST be open.
The boiler power has NOT been correctly set for the installation.Adjust the power.
No heat transfer as a result of lime scale or fouling in the heat exchanger.Descale or flush the heat exchanger on the space heating side.
The burner is NOT firing on domestic hot water: S3 faulty.Replace S3.

Daikin BPMK928B42 Heat Pump Troubleshooting

CodeFailure causeCorrective action
R1Failure of writing memory (EEPROM error)Contact your local dealer.
R6Malfunction of pump in water circuit (МІР)• Make sure waterflow is possible (open all valves in the circuit).
• Force clean water through the unit.
R9R410A expansion valve error (K1E)• Check wiring connections.
RRHeater kit thermal cut out error (if the heater kit option installed)• Make sure the circuit is filled with water (no air inside).
• Make sure waterflow is possible (open all valves in the circuit).
Heater kit connected to the benefit kWh rate power supplyMake sure the heater kit is connected to a normal power supply.
RJCapacity errorContact your local dealer.
C1Bad ACS communication
С4R410A liquid thermistor error (R3T)
C5Domestic hot water tank thermistor error (R2T)
• Check if the domestic hot water option is turned active (refer to field setting [6-00]).
С9Returning water thermistor error (R4T)• Check wiring connections.
CRLeaving water thermistor error (R5T)
СJRemote controller thermostat thermistor error
E1Compressor PCB error
ЕЗHigh pressure error (S1PH)• Check wiring connections on outdoor unit and indoor unit.
• Make sure the circuit is filled with water (no air inside, e.g. is the air purge open?)
• Make sure the domestic hot water tank is filled with water.
• Make sure water flow is possible (open all valves in the circuit).
• Make sure the water filter is not blocked.
• Make sure all refrigerant stop valves are open.
• Contact your local dealer.

Daikin ALTHERMA ERLQ014CAW1 Heat Pump Troubleshooting

Error codeCausePossible solution
10,11,Sensor fault S1• Check wiring
12, 13, 14• Replace S1
20,21, 22, 23, 24Sensor fault S2• Check wiring
• Replace S2
0Sensor fault after self-checkReplace S1 and/or S2
1Temperature too high• Air in installation
• Pump is NOT running
• Insufficient flow in installation
• Radiators are closed
• Pump setting is too low
2S1 and S2 interchanged• Check cable set
• Replace S1 and S2
4No flame signal• Gas tap is closed
• No or incorrect ignition gap
• Gas supply pressure is too low or fails
• Gas valve or ignition unit is NOT powered
5Poor flame signal• Condensate drain blocked
• Check adjustment of gas valve
6Flame detection fault• Replace ignition cable and spark plug cap
• Replace ignition unit
• Replace boiler controller
8Incorrect fan speed• Fan catching on casing
• Wiring between fan and casing
• Check wiring for poor wire contact
• Replace fan
29, 30Gas valve relay faultReplace boiler controller

Daikin EKHBRD014ADV1 Heat Pump Troubleshooting

Pump is making noiseThere is air in the system.Purge air.
Water pressure at pump inlet is too low.• Check on the manometer that there is sufficient water pressure. The water pressure must be >0.3 bar (water is cold), »0.3 bar (water is hot).
• Check that the manometer is not broken.
• Check that the expansion vessel is not broken.
• Check that the setting of the pre-pressure of the expansion vessel is correct
The water pressure relief valve opensThe expansion vessel is broken.Replace the expansion vessel.
The water volume in the installation is too high.Make sure that the water volume in the installation is under the maximum allowed value
The water pressure relief valve leaksDirt is blocking the water pressure relief valve outlet.Check for correct operation of the pressure relief valve by turning the red knob on the valve counter clockwise:
• If you do not hear a clacking sound, contact your local dealer.
• In case the water keeps running out of the unit, close both the water inlet and outlet shut-off valves first and then contact your local dealer.
The user interface displays "not available" when pressing certain buttonsThe current permission level is set to a level that prevents using the pressed button.Change the "user permission level" field setting
Space heating capacity shortage at low outdoor temperaturesThe heater kit is not activated.Check that the "heater kit operation status" field setting is turned on

Daikin EGSQH Heat Pump Troubleshooting

You are feeling too cold (hot) in your living roomThe desired room temperature is too low (high).Increase (decrease) the desired room temperature.
If the problem recurs daily, do one of the following:
• Increase (decrease) the room temperature preset value.
• Adjust the room temperature schedule.
The desired room temperature cannot be reached.Increase the desired leaving water temperature in accordance with the heat emitter type.
You ran out of domestic hot water because of unusual high consumption.If you immediately need domestic hot water, activate the DHW tank booster mode. However, this consumes extra energy.
If you can wait, overrule (increase) the active or next scheduled desired temperature so that more hot water will be produced exceptionally.
If the problems recurs daily, do one of the following:
• Increase the DHW tank temperature preset value.
• Adjust the DHW tank temperature schedule. Example: Program to additionally heat up the DHW tank to a preset value (Storage eco = lower tank temperature) during the day.
The desired DHW tank temperature is too low.
Heat pump failureHeat pump is damaged.• Press GO to view a description of the problem.
• Press again.
• Select OK to allow the backup heater to take over the heat load.
• Call your local dealer to get the heat pump fixed.

Daikin FTX25JVEA9 Heat Pump Troubleshooting

Problem with…Code IndicationDescription of Problem
UOInsufficient gas
U2Power factor module abnormality
U4Signal transmission error (between indoor and outdoor units)
U5Signal transmission error (between indoor unit and remote controller)
Indoor UnitR1Faulty indoor unit PCB
R3Faulty drainage
R5Operation halt due to the freeze protection function or high pressure control
R6Fan motor or related abnormality
C4 or C5Heat exchanger temperature thermistor abnormality
C9Room temperature thermistor abnormality
CRDischarge air temperature thermistor abnormality
Outdoor UnitE5OL activation (IT activation) or High discharge pipe temperature
E6Compressor startup error
F3Operation halt due to discharge pipe control function
H8CT or related abnormality
H9Outside air thermistor or related abnormality
J3Discharge pipe temperature thermistor or related abnormality
J6Heat exchanger temperature thermistor or related abnormality
J9Gas pipe temperature thermistor or related abnormality
L4Radiation fin temperature rise
P3Heat radiation fin thermistor or related abnormality
P4Heat radiation fin thermistor or related abnormality
E0Protectors Function

Daikin FTX25JVEA6 Heat Pump Troubleshooting

UNIT DOES NOT START• Unit may have become unplugged• Check that plug is plugged securely in wall receptacle.
• Fuse may have blownNote Plug has a test/reset button on it. Make sure that the plug has not tripped.
• Circuit breaker may have been tripped• Replace the fuse.
• Unit may be off or in wall thermostat mode. Check section on dipswitch settings to verify dipswitches are set properly.• Reset circuit breaker.
• Unit may be in a protection or diagnostic failure mode. See section on Intelligent Self-checking Control.• Turn unit on (bottom right button on keypad).
Note: If the unit turns on. the LED will be green. If the unit is off. the LED will be red. If there is no LED on. there is a problem with power or damage to the control.
UNIT NOT COOLING/HEATING ROOM• Unit air discharge section is blocked• Make sure that curtains, blinds or furniture are not restricting or blocking unit airflow.
• Temperature setting is not high or low enough Note: Setpoint limits may not allow the unit to heat or cool the room to the temperature desired.• Reset to a lower or higher temperature setting.
Check section on dipswitch settings.• Remove and dean filters.
• Unit air filters are dirty.• Allow sufficient amount of time for unit to heat or cool the room. Start heating or cooling early before outdoor temperature, cooking heat or gatherings of people make room uncomfortable.
• Room is excessively hot or cold when unit is started.• Close vent door.
• Vent door left open• Check dipswitch settings for desired comfort.
• Unit may be in a protection or diagnostic failure mode. Check section on Intelligent Self-checking Control.Wait approximately 3 minutes for compressor to start
• Compressor is in time delay. There is a protective time delay (approx. 3 minutes) on starting the compressor after a power outage (or restarting after it has been turned off), to prevent tripping of the compressor overload.
DISPLAY HAS STRANGE NUMBERS/CHARACTERS ON IT• The unit may be in a diagnostic condition. Check Intelligent Self- checking Control section to determine if unit has had a failure.
• The unit may be set for “C (instead of °F). see the keypad configuration section
UNIT MAKING NOISES• Clicking, gurgling and whooshing noises are normal during operation of unit.
WATER DRIPPING OUTSIDE• If a drain kit has not been installed, condensation runoff during very hot and humid weather is normal If a drain kit has been installed and is connected to a drain system, check gaskets and fittings around drain for leaks and plugs.
WATER DRIPPING INSIDE• Wall sleeve is not installed level• Wall sleeve must be installed level for proper drainage of condensation. Check that installation is level and make any necessary adjustments.
ICE OR FROST FORMS ON INDOOR COIL• Low outdoor temperature• When outdoor temperature is approximately 55*F (12.8*C) or below, frost may form on the indoor coil when unit is in Cooling mode. Switch unit to FAN operation until ice or frost melts.
• Dirty filters• Remove and clean filters.
COMPRESSOR PROTECTION• Power may have cycled, so compressor is in a restart protection.• Random Compressor restart - Whenever the unit is plugged in, or power has been restarted, a random compressor restart will occur. After a power outage, the compressor will restart after approximately 3 minutes.
• Compressor Protection - To prevent short cycling of the compressor, there is a random start-up delay of 3 minutes and a minimum compressor run time of 3 minutes.

Daikin RMK140JVMC8 Heat Pump Troubleshooting

Indoor Unit LED Indication AIndoor Unit LED Indication BDescription of the Fault
Indoor unit in normal condition (Conduct a diagnosis of the outdoor unit.)
Operation halt due to the freeze protection function or high
pressure control (heat pump model only)
Faulty fan motor (AC motor stop)
Heat exchanger temperature thermistor or related abnormality
Suction thermistor or related abnormality
Discharge thermistor or related abnormality
Faulty indoor unit PCB
Faulty power supply or indoor unit PCB
Signal transmission error (between indoor and outdoor units)
Signal transmission error (between indoor unit and remote controller)