LG Heat Pump Error Code P517

P517 is an outdoor unit discharge temperature 2 protection code on LG heat pumps. It means the temperature sensor on the compressor discharge line detected temperatures high enough to trigger a system shutdown. The unit enters this protection mode to prevent serious internal compressor damage. The fault must be diagnosed and resolved before the system will operate normally.

No. The P517 code exists specifically to protect the compressor from heat-related damage. Attempting to bypass or ignore the protection control and continue running the unit risks permanent compressor failure, which is the most costly component in the system. The unit should remain off until the underlying cause is identified and corrected.

Repair costs vary widely depending on the cause. Coil cleaning or a sensor replacement typically falls in the range of $100 to $350. Refrigerant recharge with leak repair can range from $200 to $600 or more. Compressor replacement is the most expensive scenario, often ranging from $1,000 to $2,500 or higher depending on the model and labor involved.

Some causes, such as clearing debris from the outdoor coil or improving airflow around the unit, can be addressed without professional help. However, diagnosing low refrigerant, a faulty sensor, or a failing compressor requires refrigerant handling certification and specialized tools. Most cases of P517 will need a qualified HVAC technician to properly identify and correct the root cause.

A power reset may clear the fault temporarily if the discharge temperature has dropped back into a safe range. However, if the underlying cause such as low refrigerant or a blocked coil is not resolved, the error will return once the unit runs and temperatures climb again. A reset is not a repair, only a short-term workaround.