LG Heat Pump Error Code P711

P711 means the compressor has been shut down by the high pressure sensor protection control. The system detected refrigerant pressure on the high side of the circuit exceeding safe operating limits and halted the compressor to prevent damage. Common triggers include closed service valves, a malfunctioning PWM valve, or inadequate fan airflow across the coils. A technician should inspect all three areas before restarting the unit.

No. The P711 code indicates the system has already shut down the compressor as a protective measure. Attempting to bypass or repeatedly reset the unit without addressing the underlying cause risks serious compressor damage, refrigerant line failures, or other costly component failures. The system should remain off until the root cause has been diagnosed and corrected.

A power reset may temporarily clear the P711 fault and allow the system to restart, but if the underlying cause is not corrected, the error will return and the compressor will shut down again. Repeated high-pressure shutdowns can accelerate wear on the compressor and other components. A reset should only be performed after the cause has been identified and resolved, not as a substitute for diagnosis.

Some preliminary checks, such as confirming service valves are fully open and verifying that the indoor and outdoor fans are running without obstructions, can be done without special tools. However, inspecting the PWM valve coil resistance, testing the high pressure sensor, and diagnosing refrigerant charge issues require gauges and electrical diagnostic equipment that most homeowners do not have. For anything beyond basic visual checks, a qualified HVAC technician should handle the repair.

Repair costs vary widely depending on the root cause. A simple service valve adjustment or connector repair may cost between $75 and $200 for a service call. Replacing a PWM valve coil or fan motor can range from $150 to $500 or more depending on parts and labor rates in your area. If the compressor has already sustained damage from repeated high-pressure events, costs can be significantly higher.