LG Heat Pump Error Code P8

The P8 code means the compressor has been shut down by the low pressure protection circuit. During cooling, this triggers when low-side pressure drops below 3 kg/cm2G, and during heating it triggers below 0.5 kgf/cm2G before a pump down cycle starts. The most common causes are a refrigerant leak, a failed indoor fan motor, or a malfunctioning electronic expansion valve. The system will remain locked out until the root cause is corrected.

No. The P8 code indicates the compressor has already been shut down by a safety protection circuit, meaning the unit is not providing heating or cooling. Attempting to force the system to run without resolving the underlying low pressure condition can cause serious and potentially irreversible compressor damage. The system should remain off until a qualified technician diagnoses and repairs the fault.

Repair costs vary widely depending on the root cause. A coil cleaning or fan motor inspection may cost between 75 and 150 dollars for a service call. If a refrigerant leak is involved, leak detection, repair, and recharge can range from 200 to 600 dollars or more depending on the location and severity of the leak. EEV or pressure sensor replacement parts and labor typically range from 150 to 400 dollars. A full diagnosis by a qualified technician is the best way to get an accurate estimate.

Some basic checks, such as inspecting the indoor fan operation, cleaning a blocked air filter or coil, and checking for obvious wiring issues at the EEV, can be performed by a knowledgeable DIYer. However, if the problem involves refrigerant shortage, a leak search, and system recharge require EPA Section 608 certification and proper equipment. EEV replacement and pressure sensor diagnostics also generally require professional service tools.

A power reset may temporarily clear the P8 display and allow the unit to attempt a restart, but the error will return quickly if the underlying cause has not been addressed. If refrigerant pressure remains below the protection threshold, the compressor will shut down again within a short time. A reset alone is not a repair and should only be used as part of a diagnostic process, not as a solution.