LG Heat Pump Error Code CH23

CH23 indicates that the DC link voltage inside the heat pump's inverter section has fallen below the minimum required level. For single-phase units, this threshold is 140Vdc, and for three-phase units it is 250Vdc. The system shuts down automatically to protect the compressor from running under inadequate voltage conditions. The fault points to either a power supply issue or a failing internal electrical component.

No. CH23 causes the unit to shut down specifically to prevent compressor damage from low voltage operation. Attempting to bypass the fault or repeatedly resetting and running the unit without identifying the cause can damage the compressor or inverter board. The unit should remain off until the underlying cause is diagnosed and corrected.

Repair costs vary widely depending on the cause. If the fix involves tightening connections or correcting a circuit issue, costs may be limited to a service call fee, typically in the range of $75 to $200. If the DC link capacitors or inverter board need replacement, parts and labor combined can range from $300 to $900 or more depending on the unit size and part availability. Getting a diagnostic visit first will clarify exactly what parts are needed.

Basic checks such as inspecting the circuit breaker, verifying the disconnect is fully closed, and looking for obviously loose wiring at accessible terminals can be done carefully by a knowledgeable homeowner. However, measuring DC link voltage and testing internal components like capacitors and rectifiers involves working with high-voltage DC circuits, which is hazardous without proper training and equipment. A qualified HVAC technician should perform the full diagnostic procedure.

A power reset may temporarily clear the fault code and allow the unit to restart, but if the underlying cause has not been corrected, CH23 will return, often immediately or at the next compressor start attempt. Persistent or recurring CH23 faults after a reset indicate an active electrical problem that requires diagnosis rather than simply clearing the code.