LG HVAC Error Code 23

Error code 23 means the inverter's DC link voltage has dropped below the minimum acceptable level. The system monitors the internal DC bus voltage that powers the variable-speed compressor drive, and it shuts down when that voltage is too low. The required AC supply to the unit must be between 193 and 253 volts AC. The fault can be caused by a low supply voltage or a failed inverter PCB.

No. Error code 23 causes the system to shut down as a protective measure, and the unit will not operate normally while this fault is active. Attempting to force operation with low DC link voltage risks damaging the inverter components and compressor, which are expensive to replace. Leave the system off until the root cause is diagnosed and corrected.

Resetting the unit by cycling power may temporarily clear the fault display, but the error will return if the underlying cause is not corrected. If the supply voltage is consistently below 193V AC or the inverter PCB is faulty, the system will detect the low DC link voltage again and re-enter the fault state. A reset is useful for confirming the fault is repeatable, but it is not a fix.

Some basic checks are within reach of a knowledgeable homeowner, such as confirming the circuit breaker is fully seated and not tripped. However, measuring voltages at the unit's terminal block and diagnosing the inverter PCB require a multimeter, electrical safety knowledge, and familiarity with HVAC systems. Most repairs beyond the breaker check should be handled by a licensed HVAC technician.

Repair cost depends on the cause. If the issue is a loose connection or a tripped breaker, the cost may be limited to a service call fee, typically in the range of $75 to $150. If the inverter PCB has failed and requires replacement, parts and labor combined can range from $400 to over $1,000 depending on the specific unit model and local labor rates.