LG Air Conditioner Error Code CH23

CH23 indicates a DC link low voltage fault in the outdoor unit's inverter drive circuit. The PCB monitors the DC bus voltage and triggers this error when that voltage drops below 140V. The system requires this condition to occur 5 times before displaying the code and shuts the compressor off each time to prevent damage.

A power reset may temporarily clear the displayed fault, but CH23 only appears after 5 low-voltage detection events, so the underlying problem is already recurring. If the root cause is not repaired, the voltage drop will continue to occur, the compressor will keep shutting down, and the error will return. A reset alone is not a fix.

Repair costs vary depending on the root cause. If the issue is a low supply voltage or loose wiring connection, costs may be limited to a service call fee, typically in the range of $75 to $150. If DC link capacitors need replacement, parts and labor can range from $150 to $400. An outdoor unit PCB or IPM replacement can bring total costs into the $400 to $900 range or higher depending on the model and parts availability.

Because CH23 involves the high-voltage DC bus inside the outdoor unit, this fault is not safe for untrained individuals to diagnose or repair. The DC link capacitors hold dangerous voltage even after the unit is powered off and require a proper discharge procedure. A licensed HVAC or appliance technician should perform all diagnostics and repairs on this fault.

No. The system shuts the compressor off each time the DC link voltage drops below 140V specifically to protect the compressor and inverter components from damage. Continuing to operate the unit with this fault present risks permanent damage to the compressor, IPM, or outdoor PCB. The unit should be taken out of service until the fault is diagnosed and repaired.