No malfunction detected (normal status)
No malfunction detected in self-diagnosis mode · Temporary status after a diagnostic check or reset · Issue may be intermittent if cooling complaint still exists
Learn what common Daikin error codes mean, what typically causes them, and whether they need urgent attention.
This is a guidance table, not a model-exact diagnosis. The same code can differ by series, controller, and model year. Use this page to narrow next steps, then verify with model sticker details.
Safety Warning
Stop using the unit and contact a technician if the breaker trips repeatedly, you smell burning, see sparks, hear loud electrical buzzing, or water is leaking from places it normally should not.
No malfunction detected (normal status)
No malfunction detected in self-diagnosis mode · Temporary status after a diagnostic check or reset · Issue may be intermittent if cooling complaint still exists
Indoor unit PCB or control abnormality
System control logic detected abnormal operation · Wiring/communication mismatch · Controller or PCB fault
Indoor and outdoor unit mismatch
System control logic detected abnormal operation · Wiring/communication mismatch · Controller or PCB fault
Indoor unit transmission error
Loose or reversed interconnection wiring · Poor terminal contact/corrosion · Indoor/outdoor PCB communication circuit fault · Power instability
Indoor refrigerant temperature sensor abnormal
Temperature sensor open/short · Sensor connector loose · Sensor circuit fault on indoor PCB
Indoor air temperature sensor abnormal
Temperature sensor open/short · Sensor connector loose · Sensor circuit fault on indoor PCB
Abnormal water level in thermal storage unit
Abnormal water level signal from storage tank · Level sensor fault or wiring issue · Control board interpretation error
Radiation/auxiliary fan system malfunction
Radiation fan or auxiliary fan circuit fault · Fan motor/driver PCB problem · Communication issue in fan control chain
Indoor PCB fault
Indoor PCB/component failure · Loose or oxidised internal connectors · Moisture or surge damage on control board
Drain water level fault / drainage problem
Blocked drain pipe or trap · Faulty or stuck drain pump/float switch · Heavy dirt buildup in drain pan
Indoor heat exchanger overheat/freeze protection triggered
Dirty indoor coil or filter reducing airflow · Low refrigerant charge from leak · Indoor thermistor reading out of range
Indoor fan motor lock or overload
Fan motor lock or winding fault · Motor connector loose or damaged · Indoor PCB drive circuit fault
Swing flap motor fault
Swing flap motor jammed or faulty · Disconnected swing motor harness · Indoor PCB output fault
Indoor overcurrent or abnormal AC input
Abnormal indoor input current or power surge · Wiring short or poor terminal contact · Indoor power circuit/PCB fault
Electronic expansion valve (EEV) fault
Electronic expansion valve stuck or coil faulty · Valve harness disconnection · Control PCB drive fault
Capacity setting or addressing error
Incorrect indoor/outdoor capacity setting · DIP switch or field setting mismatch · Control PCB setting error
Drain water level sensor abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Indoor heat exchanger thermistor abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Liquid pipe thermistor abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Indoor fan motor thermistor abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Indoor suction air thermistor abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Radiation thermistor resistance abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Remote controller thermistor abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Outdoor protection device activated
Outdoor protection device triggered · Compressor or fan motor electrical fault · Refrigerant circuit abnormality
High pressure protection activated
Dirty condenser or blocked outdoor airflow · Outdoor fan problem · Refrigerant overcharge or non-condensables
Low pressure protection activated
Low refrigerant due to leak · Expansion device or piping restriction · Insufficient heat load or sensor/control fault
Compressor overload / overcurrent protection
Compressor overcurrent or thermal overload · Voltage instability or wiring fault · Refrigerant restriction causing high load
Compressor lock or startup failure
Compressor lock/start failure · Inverter drive fault · Mechanical compressor fault
Outdoor fan motor lock fault
Outdoor fan motor lock · Fan motor connector/drive fault · Outdoor PCB failure
Outdoor overcurrent protection
Outdoor unit current spike · Compressor winding or power module issue · Power supply instability
Low refrigerant or suction temperature abnormal
Low refrigerant due to leak · Expansion device or piping restriction · Insufficient heat load or sensor/control fault
Outdoor discharge pipe temperature too high
Restricted refrigerant flow or low charge · Discharge thermistor abnormal · Compressor running under high load
Outdoor heat exchanger temperature high
Restricted refrigerant flow or low charge · Discharge thermistor abnormal · Compressor running under high load
High pressure switch fault
Dirty condenser or blocked outdoor airflow · Outdoor fan problem · Refrigerant overcharge or non-condensables
Low pressure switch fault
Low refrigerant due to leak · Expansion device or piping restriction · Insufficient heat load or sensor/control fault
Compressor position sensor fault
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Outdoor air temperature thermistor fault
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Refrigerant pressure sensor fault
Pressure sensor faulty or out of calibration · Sensor wiring issue · Outdoor PCB input fault
Discharge pipe thermistor fault
Pipe thermistor fault or displacement · Refrigerant circuit anomaly · Sensor harness/PCB input fault
Suction pipe thermistor fault
Pipe thermistor fault or displacement · Refrigerant circuit anomaly · Sensor harness/PCB input fault
Outdoor heat exchanger thermistor fault
Pipe thermistor fault or displacement · Refrigerant circuit anomaly · Sensor harness/PCB input fault
Discharge pressure sensor fault
Pressure sensor faulty or out of calibration · Sensor wiring issue · Outdoor PCB input fault
Suction pressure sensor fault
Pressure sensor faulty or out of calibration · Sensor wiring issue · Outdoor PCB input fault
Inverter system fault
Inverter IPM/power transistor fault · Compressor electrical abnormality · Heatsink overheating or weak airflow · Supply voltage fluctuation
Electrical parts overheating in inverter section
Inverter IPM/power transistor fault · Compressor electrical abnormality · Heatsink overheating or weak airflow · Supply voltage fluctuation
Inverter heatsink temperature too high
Inverter IPM/power transistor fault · Compressor electrical abnormality · Heatsink overheating or weak airflow · Supply voltage fluctuation
Inverter overcurrent / compressor lock protection
Inverter IPM/power transistor fault · Compressor electrical abnormality · Heatsink overheating or weak airflow · Supply voltage fluctuation
Power transistor (IPM) fault
Inverter IPM/power transistor fault · Compressor electrical abnormality · Heatsink overheating or weak airflow · Supply voltage fluctuation
Phase loss or voltage imbalance (3-phase)
Phase loss or reverse phase on supply · Voltage imbalance · Main power wiring fault
Inverter heatsink thermistor abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
DC current sensor abnormal
Thermistor/sensor open or short circuit · Loose or disconnected sensor connector · Sensor harness damage or PCB input fault
Inverter main circuit DC voltage abnormal
Inverter IPM/power transistor fault · Compressor electrical abnormality · Heatsink overheating or weak airflow · Supply voltage fluctuation
AC input overcurrent
Outdoor unit current spike · Compressor winding or power module issue · Power supply instability
Field setting / capacity setting fault
Incorrect indoor/outdoor capacity setting · DIP switch or field setting mismatch · Control PCB setting error
Refrigerant shortage or suction temperature abnormal
Low refrigerant due to leak · Expansion device or piping restriction · Insufficient heat load or sensor/control fault
Reverse phase power supply
Phase loss or reverse phase on supply · Voltage imbalance · Main power wiring fault
Power supply fault (voltage drop/open phase)
Phase loss or reverse phase on supply · Voltage imbalance · Main power wiring fault
Check operation not completed / test run setting error
Indoor/outdoor model combination mismatch · Addressing or field setting error · PCB setup/configuration fault
Communication error between indoor and outdoor units
Loose or reversed interconnection wiring · Poor terminal contact/corrosion · Indoor/outdoor PCB communication circuit fault · Power instability
Communication error between indoor unit and remote controller
Remote-controller cable loose/damaged · Remote controller board fault · Indoor PCB communication fault
Communication error between outdoor units
Loose or reversed interconnection wiring · Poor terminal contact/corrosion · Indoor/outdoor PCB communication circuit fault · Power instability
Indoor/outdoor combination or setting mismatch
Indoor/outdoor model combination mismatch · Addressing or field setting error · PCB setup/configuration fault
System addressing/initialisation communication fault
Indoor/outdoor model combination mismatch · Addressing or field setting error · PCB setup/configuration fault
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