LG Air Conditioner Error Code CH27

CH27 on an LG air conditioner indicates a PSC Fault Error, meaning the system has detected an abnormality in the control circuit section of the main PCB. This is an internal board-level fault that causes the unit to shut down to prevent further damage. It is not related to a sensor or refrigerant issue. A technician will need to inspect the control board directly.

No, you should not attempt to continue operating the unit when CH27 is displayed. The error indicates an internal circuit fault that could worsen with continued use and may pose an electrical risk. The unit typically shuts itself down automatically, and it should remain off until a technician has inspected and repaired the control board.

Repair costs for a CH27 fault depend primarily on whether the main PCB needs to be replaced or if a component-level board repair is possible. PCB replacement parts and labor can range from roughly $150 to $500 or more depending on the unit model and service provider. Diagnostic fees may also apply before repair costs are confirmed.

The CH27 fault is specific to the internal control circuit of the main PCB, which requires board-level diagnostic skills and proper test equipment to evaluate. Most homeowners will not have the tools or training to safely diagnose this fault. It is strongly recommended to contact a qualified HVAC or appliance technician for this repair.

A power reset may temporarily clear the CH27 code in some cases, but if the underlying PCB control circuit fault remains, the error will return. Because this fault points to a hardware-level problem on the control board, a reset does not constitute a repair. If the code reappears after a reset, professional service is necessary.