LG Heat Pump Error Code E443

E443 indicates that the LG heat pump detected an instant power-off condition, meaning the control board sensed a brief interruption in electrical supply. This fault is specifically tied to the compressor startup sequence and disappears once the compressor begins running. It is a protective code designed to prevent compressor damage from voltage instability during the high-current startup period.

The code itself is a protective measure, not an immediate safety emergency, but the underlying cause can be a concern. Loose wiring connections or an undersized circuit that causes repeated voltage dropout can lead to arcing, overheating, and accelerated wear on the compressor and contactor. Addressing the root cause promptly reduces the risk of more serious electrical or component failures.

Repair costs depend on the root cause. If the issue is simply a loose wiring connection, a service call to diagnose and correct it may run in the range of $75 to $200 for labor. Replacing a contactor typically costs $150 to $350 including parts and labor. If the circuit wiring or panel needs to be upgraded to meet the unit's electrical requirements, electrical work costs can range from $200 to $800 or more depending on the scope.

Some basic checks, like verifying the circuit breaker, inspecting for tripped disconnects, and confirming the unit has a dedicated circuit, can be done without special tools. However, checking line voltage under load, inspecting contactor contacts, and torquing high-voltage terminal connections involves working inside live electrical panels and equipment, which should be handled by a qualified technician. Repeated occurrences of E443 warrant a professional inspection.

Because E443 disappears on its own once the compressor is running, a reset may appear to resolve it temporarily. However, if the underlying cause, such as a voltage sag, loose connection, or weak contactor, is not corrected, the code will return on the next startup attempt. A reset does not fix the electrical condition that triggered the fault.