Daikin Air Conditioner Error Code E5

E5 on a Daikin air conditioner indicates an inverter compressor motor lock fault. The inverter control has detected that the compressor motor is not rotating after being energized. The system shuts down automatically to prevent damage to the compressor and inverter components. This fault can be caused by mechanical seizure, electrical winding faults, a ground fault, or a closed service valve.

No. The E5 fault indicates the compressor has locked up or cannot rotate, and the system has already shut down as a protective measure. Attempting to override or repeatedly restart the unit without resolving the underlying fault can cause further damage to the inverter board or the compressor. Leave the unit off until the root cause is identified and corrected.

A power reset may temporarily clear the fault display, but E5 will return immediately on the next startup attempt if the underlying problem has not been corrected. The inverter continuously monitors compressor rotation, so any reset without a repair will result in the same lockout. A reset is only useful after a confirmed repair has been completed to verify that the fault no longer recurs.

Some checks, such as confirming that the service stop valves are fully open, can be performed without specialized tools. However, diagnosing compressor winding resistance, insulation resistance, and inverter output voltages requires a multimeter and megohmmeter, along with knowledge of safe electrical procedures. Compressor replacement and refrigerant handling must be performed by a licensed HVAC technician.

Repair costs depend entirely on the root cause. Correcting a closed stop valve costs little beyond a service call fee, typically in the range of $75 to $150. Inverter board replacement can range from $300 to $800 in parts and labor. Compressor replacement is the most expensive outcome, often ranging from $800 to $2,500 or more depending on the unit size and refrigerant type involved.