LG Heat Pump Error Code E252

E252 indicates a discharge temperature sensor fault for fixed capacity compressor 2. The control board has detected that the sensor signal voltage is either above 4.95V (open circuit, reading below -30°C) or below 0.5V (short circuit, reading above 151°C). This error is only triggered when outdoor temperatures are above -10°C. The system shuts down to protect the compressor until the sensor issue is resolved.

No. The discharge sensor protects compressor 2 from overheating by providing real-time temperature data to the control board. Operating the system without a valid sensor reading removes that protection and risks serious compressor damage. The unit should remain off until the fault is diagnosed and repaired.

A power reset may temporarily clear the error code, but if the underlying sensor fault is still present, E252 will return once the control board re-evaluates the sensor signal. Because the error condition is based on a specific voltage threshold being exceeded, the fault will persist until the sensor connector, wiring, or thermistor is repaired or replaced.

Checking the sensor connector for loose or corroded pins is something a knowledgeable DIYer can do safely with the unit powered off. However, measuring thermistor resistance and accessing components inside the outdoor unit typically requires familiarity with refrigerant systems and electrical testing. If the connector appears intact and the sensor reads out of specification, sensor replacement is best handled by a qualified technician.

Costs vary depending on what has failed. A sensor replacement alone typically ranges from $75 to $200 or more in parts, plus labor. If the wiring harness is damaged, repair costs may be higher. Diagnostic service calls generally range from $80 to $150 before any parts or repair work is performed.