LG Heat Pump Error Code P772

P772 indicates an outdoor unit compression rate 2 error, meaning the ratio between the compressor's discharge pressure and suction pressure has moved outside of acceptable limits. This fault signals that the refrigeration cycle is not operating within its designed pressure parameters. The system may shut down to protect the compressor from damage. A technician with refrigerant handling certification should diagnose the underlying cause.

It is not recommended to continue running the heat pump when P772 is active. Operating the system with an abnormal compression ratio can cause the compressor to overheat or sustain internal damage over time. The system may cycle off automatically as a protective measure. Leave the unit off until the fault has been diagnosed and repaired.

Repair costs vary significantly depending on the cause. A coil cleaning or sensor replacement might cost anywhere from $100 to $300. Refrigerant recharge services typically range from $200 to $600 depending on refrigerant type and the amount needed. Compressor replacement is the most expensive scenario, often ranging from $1,000 to $2,500 or more including labor.

Most causes of P772 require professional tools and certifications to address properly. Checking for obvious issues like a blocked outdoor coil or a non-spinning fan motor is something a homeowner can do safely. However, checking refrigerant pressure, recharging refrigerant, or replacing a compressor all require a licensed HVAC technician and specialized equipment.

A power reset may temporarily clear the P772 code, but if the underlying condition causing the abnormal compression ratio is still present, the fault will return after the system restarts and runs through its operating cycle. A reset alone does not fix the root cause. The fault should be properly diagnosed rather than repeatedly reset.