LG HVAC Error Code 29

Error code 29 on an LG HVAC system indicates the inverter compressor is drawing excessive amperage. The system shuts down automatically to protect the compressor and the inverter drive electronics. Common causes include high head pressure, incorrect supply voltage, and compressor winding faults. A technician should diagnose the root cause before restarting the unit.

No. Error code 29 is a protective shutdown, meaning the system has already stopped the compressor to prevent damage. Repeatedly resetting and restarting the unit without resolving the cause can permanently damage the compressor or the inverter drive board. The system should remain off until a technician identifies and corrects the underlying issue.

A power reset may temporarily clear the fault and allow the unit to restart, but if the underlying cause is still present, the system will detect high amperage again and the code will return. Resetting without repair is not a solution and risks worsening the damage to the compressor or drive board. The fault should be fully diagnosed before the unit is returned to service.

Some preliminary checks, such as clearing debris from the outdoor condenser coil and verifying the unit's circuit breaker is the correct size, can be done by a homeowner. However, checking supply voltage under load, measuring refrigerant pressures, and testing compressor winding resistance require proper tools and training. Most repairs that address code 29 should be handled by a licensed HVAC technician.

Repair costs vary widely depending on the root cause. If the issue is simply a dirty condenser or a voltage supply correction, costs may be minimal, typically in the range of a standard service call fee of $75 to $150. Inverter drive board replacement can range from $300 to $700 depending on the model. Compressor replacement is the most expensive outcome, often ranging from $800 to $2,000 or more including labor.