Skip to main content
Error code reference
Daikin Heat Pump Error Codes
37 error codes documented with diagnostic procedures.
Have your model number? Get codes specific to your unit.
00Normal operation, no fault detected.A1Indoor unit PCB abnormality; the system cannot set the internal settings.A3Drain level control system abnormality-water level reaches upper limit and float switch…A5Freeze-up protection control (cooling) or heating peak-cut control (heating) activated.A6Indoor fan motor (DC motor) or related abnormality; detected rotation speed does not…AFHumidifier or related abnormality-water leakage from humidifier detected based on float…C4Indoor heat exchanger thermistor 1 (liquid pipe) (R2T) or related abnormality-thermistor…C5Indoor heat exchanger thermistor 2 (R3T) or related abnormality-thermistor disconnected…C7Front panel open/close fault.C9Room temperature thermistor (R1T) or related abnormality-thermistor disconnected or…CEPresence sensor or floor sensor abnormality-sensor disconnected or shorted while unit is…CJRemote controller thermistor abnormality-remote controller thermistor disconnected or…E1Outdoor unit PCB abnormality-microprocessor program runs out of control or zero-cross…E5OL activation (compressor overload)-compressor overload detected through compressor OL.E6Compressor lock-detected by current waveform generated when applying high-frequency…E7DC fan lock (outdoor fan motor)-fan does not start in 15-30 seconds even when fan motor…E8Input overcurrent detection-current exceeds approximately 12.0-12.5A for 2.5 seconds with…EAFour way valve abnormality-room temperature and indoor heat exchanger thermistors not…F3Discharge pipe temperature control-discharge pipe thermistor temperature rises above…F6High pressure control in cooling-outdoor heat exchanger thermistor temperature rises…F8System shutdown due to compressor internal temperature abnormality-discharge pipe…H0Compressor system sensor abnormality; DC current voltage before compressor start-up is…H6Position sensor abnormality-compressor start-up failure detected through the position…H8DC voltage/current sensor abnormality identified based on compressor running frequency…H9Outdoor temperature thermistor or related abnormality-thermistor input voltage to…J3Discharge pipe thermistor or related abnormality; discharge pipe temperature is lower…J6Outdoor heat exchanger thermistor or related abnormality-thermistor input voltage to…L3Electrical box temperature rise-radiation fin temperature is above threshold with…L4Radiation fin temperature rise-radiation fin temperature is above threshold with…L5Output overcurrent detection-position signal error, rotation speed error, or output…P4Radiation fin thermistor or related abnormality.U0Refrigerant shortage detected.U2Low-voltage detection or over-voltage detection-abnormal voltage drop or rise detected by…U4Signal transmission error between indoor unit and outdoor unit-data sent from outdoor…U5Signal transmission error between indoor unit and remote controller-normal transmission…U8Signal transmission error between MAIN remote controller and SUB remote controller-normal…UAUnspecified voltage between indoor unit and outdoor unit; pair type and multi type are…
Get the full diagnostic procedure for any code
Step-by-step tests, expected values, wiring diagram references, and verified part numbers.
Get Started $9.95 3-day pass$29/month for unlimited access to all brands and Max AI diagnostics.
More Daikin error codes
Common questions
How do I find the error code on my Daikin Heat Pump?
Most Daikin heat pumps show the code directly on the control panel display. If your model has no display, it can be read by entering diagnostic mode with the key sequence for your model. The full procedures include model-specific instructions for reading codes.
Are these codes specific to my model?
The codes here apply broadly to Daikin heat pumps. Meanings and diagnostic steps can vary by model and production year, so enter your model number for model-specific information and procedures.
What do I do if my code is not listed?
Some codes are model-specific or only appear in diagnostic mode. Enter your model number to get codes specific to your unit, or contact us. We update the database continuously from manufacturer service documentation.
How much does it cost to access the full diagnostic procedures?
A 3-day pass is $9.95 one-time and gives full access to all brands, codes, and procedures. Monthly access is $29/month with unlimited access to everything including Max AI diagnostics.