LG Heat Pump Error Code E264

E264 indicates a discharge temperature sensor breakaway fault on the third compressor. The system detected a difference greater than 40 degrees Celsius between the digital discharge temperature sensor and the fixed reference sensor at that compressor. This typically means the sensor has physically separated from the discharge line and is no longer reading the correct temperature.

No, you should not continue operating the heat pump while E264 is active. The error indicates the system cannot accurately monitor compressor discharge temperature, which is a critical protection parameter. Running the compressor without reliable discharge temperature monitoring can lead to overheating and serious compressor damage.

If the repair only requires reseating a sensor that has come loose, the cost is typically limited to a service call fee, which can range from around 80 to 150 dollars depending on location. If the sensor itself needs replacement, parts and labor together generally range from 150 to 400 dollars. Control board replacement, if required, can cost significantly more and should only be pursued after simpler causes have been ruled out.

The first step is to locate the discharge temperature sensor on the third compressor and verify it is properly attached to the discharge line or compressor body. If it has separated, reattach and secure it firmly, then clear the fault code and restart the unit. If the error returns after reseating the sensor, the sensor itself or its wiring harness may need to be replaced.

A power reset may temporarily clear the fault code, but if the underlying cause such as a separated or failed sensor has not been corrected, the error will return quickly once the compressor restarts. The root cause must be identified and repaired before the unit will operate reliably without retriggering E264.