LG · Air Conditioner

LG Air Conditioner CH05 error code

Difficulty: Medium · Cost: $0–$150 · Duration: 5–10m

The CH05 error means your LG air conditioner's indoor and outdoor units have stopped communicating with each other. This can happen right after installation or relocation if the wiring between the units was not connected correctly, or during normal use if the power supply becomes unstable. The code may also appear as E0 or CH53 on some models. A power cycle resolves it in many cases but if the error keeps returning after resetting the unit will need a professional inspection. When this error is active the indoor unit indicator light will blink every 2 seconds.

Common causes

Incorrect or loose wiring between the indoor and outdoor units during installation or relocation
Unstable or fluctuating power supply disrupting communication between units
Communication wiring damaged or disconnected
Control board fault on either the indoor or outdoor unit
Circuit breaker for the outdoor unit is tripped while the indoor unit remains powered

How to fix it

1

Unplug the power cord or turn off the circuit breaker and wait 5 minutes
2

Restore power and check if the error has cleared
3

If the error appeared right after installation check that all wiring between the indoor and outdoor units is connected correctly and securely
4

Make sure the circuit breaker for the outdoor unit has not tripped
5

If CH05, E0, or CH53 keeps returning after a power cycle contact a technician to inspect the communication wiring and control boards