LG Heat Pump Error Code P762

P762 indicates that the outdoor unit has detected a reverse phase condition in the incoming three-phase power supply. The control board monitors the rotational sequence of the three power phases, and when that sequence does not match the required order, the unit shuts down to prevent compressor damage. This is a protective fault and the unit will not operate until the phase sequence is corrected.

The unit will not run while P762 is active, which is actually a safety feature. If the lockout were bypassed and the unit operated on a reversed phase sequence, the compressor could rotate in the wrong direction, leading to severe and often irreparable internal damage. Do not attempt to bypass or override this fault.

If the fix is simply swapping two supply conductors at the disconnect, electrician labor costs are typically in the range of $75 to $200 depending on your area and the complexity of the access. If the fault is traced to a defective phase detection relay or outdoor control board, parts and labor costs can range from $300 to $800 or more. Getting a diagnosis from a certified HVAC technician first will help identify whether the issue is a simple wiring correction or a component failure.

Correcting a reverse phase condition requires working inside the disconnect box or supply panel with high-voltage three-phase power, which is dangerous and in many jurisdictions must be performed by a licensed electrician or HVAC technician. If you are comfortable and qualified working with three-phase electrical systems, you can use a phase rotation meter to confirm the issue and swap two of the supply conductors to correct the sequence. Most homeowners should not attempt this repair without professional assistance.

Resetting the outdoor unit will not permanently clear P762 if the underlying phase sequence problem has not been corrected. The fault will return immediately upon restart because the phase detection circuit will detect the same reversed phase condition. The wiring must be corrected first, after which the unit can be reset and restarted normally.