Daikin Inverter AC Error Codes

Error Code	Description	Solution
U0	Low refrigerant in the system	Check for refrigerant leaks and recharge the system with the correct amount of refrigerant.
U2	Power supply problem	Ensure the power supply is stable; check for voltage fluctuations or power failures.
U4	Communication error between indoor and outdoor units	Inspect the communication wiring between the units; repair or replace if necessary.
EA	Outdoor unit malfunction	Check the outdoor unit for issues such as fan malfunction or compressor failure. Repair or replace faulty components.
J6	Compressor overload	Check the compressor for overheating; inspect for any obstructions in airflow or excessive load on the compressor.
L5	Inverter drive error	Inspect the inverter drive and motor; reset or replace the inverter if it is faulty.
P1	High pressure in the system	Inspect for blockages in the refrigerant line and ensure proper ventilation for the outdoor unit.
P4	Overheating of the compressor	Check for proper ventilation and clean the air filters; reduce the compressor load if necessary.
P9	Outdoor air temperature sensor error	Inspect the outdoor temperature sensor; replace if it is malfunctioning.
C9	Indoor air temperature sensor error	Check the indoor temperature sensor; replace if necessary.

Indoor unit faults

AC Error Codes and Solutions

Press and hold the “Cancel” button for 5 seconds until the display shows “00.” Then, continue pressing the “Cancel” button one time at a time. If the AC beeps twice at any point during this process, it means you’ve found the correct code, and the AC will stop functioning.

Error Code	Description	Solutions
00	Normal operation	No action needed
A0	External protection	Check external connections and safety mechanisms
A1	PCB issue	Inspect or replace the printed circuit board
A2	Interlock fan problem	Verify the fan’s operation and interlock settings
A3	Drain abnormality	Check for blockages in the drain pipe
A4	Temperature abnormality at heat exchanger 1	Inspect heat exchanger 1 for temperature issues
A5	Temperature abnormality at heat exchanger 2	Inspect heat exchanger 2 for temperature issues
A6	Fan motor error	Check and possibly replace the fan motor
A7	Air swing motor error	Inspect the air swing motor and repair if needed
A8	AC input overcurrent	Check for electrical issues or overloading
A9	Expansion valve error	Examine the expansion valve for any malfunction
AA	Abnormal heater temperature	Inspect the heater for temperature irregularities
AH	Air cleaner defect	Clean or replace the air cleaner
AC	Ignition process issue	Verify the ignition system
AJ	Capacity determination device problem	Check the capacity determination system
AE	Insufficient water	Check the water supply to the unit
AF	Humidifier failure	Inspect the humidifier for faults
C0	Thermistor fault	Check and replace the thermistor if necessary
C1	Unspecified error	Consult the manual for further troubleshooting
C2	Unspecified error	Consult the manual for further troubleshooting
C3	Drain water level error	Ensure the drain water level is within acceptable limits
C4	Thermistor fault at heat exchanger 1	Inspect or replace the thermistor at heat exchanger 1
C5	Thermistor fault at heat exchanger 2	Inspect or replace the thermistor at heat exchanger 2
C6	Fan motor overload	Reduce load or replace the fan motor if needed
C7	Air swing motor locked	Unlock or repair the air swing motor
C8	AC input overcurrent	Check for electrical issues or overloading
C9	Suction line thermistor fault	Check the suction line thermistor and replace if faulty
CA	Air sensor error	Inspect or replace the air sensor
CB	Dirt sensor error	Clean or replace the dirt sensor
CC	Humidity sensor error	Check and replace the humidity sensor if needed
CJ	Remote sensor error	Inspect the remote sensor for any issues
CE	Radiation sensor error	Check the radiation sensor for faults
CF	High-pressure switch error	Verify the high-pressure switch operation