LG Heat Pump Error Code P516

P516 indicates that the outdoor unit discharge temperature protection control has been activated. This means the refrigerant temperature at the compressor outlet has reached a level that the system considers unsafe, so it enters a protective mode to prevent compressor damage. The unit may reduce its output or shut down until the condition is resolved.

A reset may temporarily clear the error and allow the unit to restart, but if the underlying cause is not corrected, the P516 code will return once the discharge temperature exceeds the protection threshold again. Repeated resets without addressing the root cause can accelerate compressor wear and lead to premature failure.

Repair costs vary widely depending on the cause. A coil cleaning service might run between $100 and $200, while a refrigerant recharge including leak repair can range from $300 to $700 or more. Replacement of a fan motor or expansion valve typically falls between $250 and $600 including labor. A compressor replacement, if the overtemperature caused internal damage, can cost $1,000 to $2,500 or higher.

Some basic checks, such as cleaning a dirty outdoor coil or removing debris blocking airflow around the unit, can be done by a homeowner. However, if the cause is low refrigerant, a faulty sensor, or an internal component like the expansion valve or fan motor, a licensed HVAC technician is required. Refrigerant handling legally requires EPA 608 certification.

You should not attempt to force the unit to operate while P516 is active. The protection control exists to prevent compressor damage, and bypassing or repeatedly resetting the error without a repair puts the compressor at risk of permanent failure. Continued operation under an overtemperature condition can also void warranty coverage.