LG Heat Pump Error Code PA

The PA code means the compressor has been shut down by the unit's protection control because the compression ratio, the ratio of high-side to low-side refrigerant pressure, exceeded 8.5 for more than 10 continuous minutes. This protection exists to prevent serious mechanical damage to the compressor. The most common causes include low refrigerant charge, a closed service valve, or a faulty electronic expansion valve.

A power reset may temporarily clear the fault display, but the PA code will return if the underlying condition causing the high compression ratio has not been corrected. Repeatedly restarting the system without addressing the root cause risks damaging the compressor. The fault should be diagnosed and repaired before returning the unit to normal operation.

Repair costs vary widely depending on the root cause. A refrigerant leak repair and recharge typically runs in the range of $200 to $600 depending on the refrigerant type and amount needed. An EEV replacement can cost $300 to $700 including parts and labor. Compressor replacement, if the unit has sustained internal damage, is significantly more expensive, generally in the range of $1,000 to $2,500 or more depending on system size and parts availability.

Some preliminary checks are within reach for a knowledgeable DIYer, such as confirming that both service valves are fully open and that there is no visible ice buildup or obvious obstruction at the outdoor unit. However, diagnosing refrigerant charge, testing EEV operation, and evaluating compressor performance require manifold gauges and refrigerant handling certification. Most PA fault repairs will need a qualified HVAC technician.

No. The PA code means the system has already shut itself down as a protective measure. Forcing the unit to operate while the compression ratio remains above safe limits can cause internal compressor damage that results in a complete compressor failure. Leave the unit off and have a technician diagnose the fault before restarting.