LG Heat Pump Error Code E502

E502 indicates that the heat pump has detected a high-side discharge pressure of 9 kg/cm² sustained for 10 minutes while operating in cooling mode. This is not a true fault code. It is a compressor ON/OFF control response activated at low outdoor temperatures to protect the refrigerant system and compressor during operation outside of ideal ambient conditions.

Yes, in most cases it is safe. E502 is a control response, not an emergency shutdown, and the unit manages its own compressor cycling to stay within safe operating limits. However, if the code appears repeatedly during normal outdoor temperatures, have the system inspected by a qualified technician to rule out refrigerant or airflow issues that could cause longer-term damage.

If E502 is caused by low outdoor temperatures in cooling mode, there is no repair cost at all since the unit is functioning as designed. If a refrigerant recharge is needed, costs typically range from $150 to $400 depending on refrigerant type and local labor rates. Outdoor fan motor replacement, if required, generally runs between $200 and $500 including parts and labor.

If the code appears during cold weather while the unit is in cooling mode, no repair is needed since this is normal protective behavior. If E502 appears at normal ambient temperatures, a technician should check the refrigerant charge, inspect the outdoor coil for blockages, and verify outdoor fan motor operation. Address any underlying refrigerant or airflow issues to resolve abnormal occurrences of this code.

Resetting the unit may clear the code temporarily, but if the underlying condition persists, such as low outdoor temperature in cooling mode or a refrigerant issue, E502 will return. For cold-weather-related occurrences, the code will stop appearing on its own once ambient temperatures rise into the unit's normal cooling operating range.