All fault codes

Daikin fault codes and error codes

What each code means, from Daikin's own service literature, and which UK models it applies to.

Daikin split air conditioning

U4Indoor/outdoor transmission error189 models U0Refrigerant shortage237 models A5Freeze-up protection (cooling) / high-pressure control (heating)255 models A6Indoor fan motor fault241 models E7Outdoor fan motor fault178 models C4Indoor heat-exchanger (liquid pipe) thermistor fault244 models C9Room / suction air thermistor fault244 models J3Discharge pipe thermistor fault280 models J6Outdoor heat-exchanger thermistor fault280 models H9Outdoor air thermistor fault280 models P4Inverter radiation-fin thermistor fault297 models E5Compressor motor overload / overheat279 models E6Compressor start failure / lock296 models H6Compressor position-detection sensor error296 models L5Inverter instantaneous over-current (DC output)276 models F3Abnormal discharge pipe temperature276 models F6Abnormal high pressure / refrigerant overcharge309 models L4Inverter radiation-fin temperature rise178 models U2Supply voltage drop / imbalance189 models A1Indoor unit PCB fault241 models E1Outdoor unit PCB fault279 models UAIndoor/outdoor combination mismatch205 models H8Compressor input current (CT) system fault296 models EACooling / heating switching error296 models H0Sensor fault (compressor system)312 models L3Electrical parts heat fault309 models

Daikin Altherma heat pumps

7H-01Water flow problem16 models E3-00High pressure switch (HPS) actuated24 models E4-00Abnormal suction pressure32 models 89-02Heat exchanger freeze-up protection (warning)12 models 8H-00Abnormal increase in outlet water temperature12 models 80-00Returning water temperature sensor problem41 models 81-00Leaving water temperature sensor problem13 models C4-00Heat exchanger temperature sensor problem16 models CJ-02Room temperature sensor problem13 models C0-00Flow sensor malfunction13 models E1-00Outdoor unit PCB defect24 models AH-00Tank disinfection not completed correctly12 models 7H-04Water flow problem during domestic hot water production13 models 7H-05Water flow problem during heating/sampling13 models 7H-06Water flow problem during cooling/defrost13 models 7H-07Water flow problem. Pump deblocking active60 models 7H-08Pump abnormality during operation (pump feedback)60 models 81-01Mixed water thermistor abnormality38 models C5-00Heat exchanger thermistor abnormality35 models H1-00External temperature sensor problem13 models H9-00OU: Malfunction of outdoor air thermistor25 models HC-00Tank temperature sensor problem13 models HC-01Second tank temperature sensor problem32 models J3-00OU: Malfunction of discharge pipe thermistor28 models J6-00OU: Malfunction of heat exchanger thermistor25 models J6-07OU: Malfunction of heat exchanger thermistor35 models J8-00Malfunction of refrigerant liquid thermistor35 models P4-00OU: Malfunction of radiating fin temperature sensor28 models H0-00OU: Voltage/current sensor problem28 models H6-00OU: Malfunction of position detection sensor28 models H8-00OU: Malfunction of compressor input (CT) system28 models E3-24High pressure sensor abnormality35 models JA-00OU: Malfunction of high pressure sensor28 models JA-17Refrigerant pressure sensor abnormality66 models HJ-10Water pressure sensor abnormality32 models C0-01Flow sensor malfunction62 models C0-02Flow sensor malfunction62 models F6-00OU: Abnormal high pressure in cooling28 models FA-00OU: Abnormal high pressure, actuation of HPS28 models H3-00OU: Malfunction of high pressure switch (HPS)28 models A5-00OU: High pressure peak cut / freeze protection problem27 models F3-00OU: Malfunction of discharge pipe temperature28 models E6-00OU: Compressor startup defect28 models L9-00Prevention of compressor lock35 models L5-00OU: Inverter instantaneous overcurrent (DC)25 models H5-00Malfunction of compressor overload protection35 models E5-00OU: Overheat of inverter compressor motor25 models P3-00Abnormal direct current35 models L1-00Malfunction of INV PCB35 models L8-00Malfunction triggered by a thermal protection in the inverter PCB32 models A1-00Zero cross detection problem16 models L3-00OU: Electrical box temperature rise problem25 models L4-00OU: Malfunction of inverter radiating fin temperature rise25 models 89-01Heat exchanger freeze-up protection activated during defrost (error)13 models 89-03Heat exchanger freeze-up protection activated during defrost (warning)13 models 89-05Heat exchanger freeze-up protection activated during cooling operation (error)40 models 89-06Heat exchanger freeze-up protection activated during cooling operation (warning)40 models 8F-00Abnormal increase outlet water temperature (DHW)16 models 8H-01Overheating mixed water circuit31 models 8H-02Overheating mixed water circuit (thermostat)32 models 8H-03Overheating water circuit (thermostat)17 models AA-01Backup heater overheated or BUH power cable not connected13 models AC-00Booster heater overheated22 models EC-00Abnormal increase tank temperature13 models AJ-03Too long DHW heat-up time required13 models U0-00OU: Shortage of refrigerant28 models E9-00Malfunction of electronic expansion valve35 models EA-00OU: Cool/heat switchover problem28 models E7-00OU: Malfunction of outdoor unit fan motor28 models E8-00OU: Power input overvoltage28 models U2-00OU: Defect of power supply voltage28 models P1-00Open-phase power supply imbalance32 models U1-00Malfunction by reverse phase/open-phase32 models E2-00Leakage current detection error35 models LC-00Malfunction in communication system of outdoor unit32 models U4-00Indoor/outdoor unit communication problem16 models U5-00User interface communication problem16 models U7-00OU: Transmission malfunction between main CPU - INV CPU27 models U8-06MMI/bizone kit communication problem57 models U8-07P1P2 communication error32 models U8-02Connection with room thermostat lost32 models U8-03No connection with room thermostat32 models U8-11Connection with the Wireless gateway lost41 models PJ-00Capacity setting mismatch35 models UA-00Indoor unit, outdoor unit matching problem16 models UA-17Tank type problem26 models U8-09MMI software version / indoor unit compatibility error60 models U8-04Unknown USB device32 models U8-05File malfunction35 models U3-00Underfloor heating screed dryout function not completed correctly13 models EC-04Tank preheating35 models UF-00Reversed piping or bad communication wiring detection35 models

Knowing the code is the easy half

A code names a symptom, not a root cause. The app takes the same code and walks the fix: what to measure first, the expected values for your exact model, and a verdict that tells you when the machine isn't actually broken.

Chase a Daikin code on your machine →

Free, no sign-up. Pick the model, put the code in, and it takes you through the chart where we hold one.

Or watch one get chased — free demo →

Or use it in your browser on any phone or laptop.

Other makes

Mitsubishi Ecodan Grant Aerona Vaillant aroTHERM Viessmann Vitocal LG Therma V Samsung EHS Panasonic Aquarea NIBE Bosch Compress Gree Midea Kaisai Haier Fujitsu Waterstage Fujitsu General Toshiba Hitachi Worcester Greenstore