LG Heat Pump Error Code G6

The G6 code means the system has detected that the fixed compressor discharge temperature sensor has separated or become disconnected from its mounting point on the discharge line. The control board compares readings from the fixed sensor and the digital compressor discharge sensor, and when the difference exceeds 30°C, the G6 fault is triggered. This typically indicates the sensor has lost physical contact with the discharge pipe and is reading ambient temperature instead of the actual discharge line temperature.

Operating the unit with a G6 fault is not recommended, as the system may not accurately monitor compressor discharge temperatures. Without reliable discharge temperature data, the heat pump could operate outside safe thermal limits without triggering protective shutdowns. It is best to address the sensor issue before continuing to run the unit.

A power reset may temporarily clear the G6 fault, but the error will return if the underlying sensor issue has not been resolved. The system is designed to detect the fault whenever the temperature differential between the two discharge sensors exceeds 30°C, so any reset is only a short-term measure. The sensor must be physically inspected, reattached, or replaced to achieve a lasting repair.

Start by powering down the unit and inspecting the fixed compressor discharge sensor on the discharge line near the compressor. If the sensor has come loose from its clip or bracket, reattach it securely to the discharge pipe and confirm it has proper contact. If the mounting hardware is broken or the sensor itself is damaged, replacement parts will be needed. After any repair, restore power and monitor the unit to confirm the error does not return.

If the fix is simply reattaching a sensor that has come loose, labor costs may range from around $75 to $150 depending on your service area and technician rates. If the sensor or mounting hardware needs to be replaced, parts costs will add to the total, typically bringing the repair into the $150 to $350 range. Costs can vary based on your specific model and local labor rates.