LG Heat Pump Error Code P513

P513 is the SUMP DOWN 1 protection control code for the outdoor unit on an LG heat pump. It indicates that the system has detected conditions in the compressor sump area that require protective action to prevent compressor damage. The unit will limit or stop operation until the condition is resolved. A technician should inspect the refrigerant charge, crankcase heater, and oil return system to identify the root cause.

No, you should not continue operating the heat pump while the P513 code is active. This protection mode exists specifically to prevent the compressor from running under conditions that could cause serious mechanical damage. Ignoring the fault and forcing the unit to run could result in compressor failure, which is a significantly more expensive repair than addressing the original cause of the fault.

Sump protection on a heat pump refers to control logic that monitors and protects the compressor oil reservoir, known as the sump, from conditions that could degrade lubrication. If liquid refrigerant mixes with the compressor oil or oil levels drop too low, the compressor can experience severe bearing and mechanical wear during startup or operation. Sump DOWN protection prevents the compressor from running under these conditions, preserving the most expensive component in the system.

A power reset may temporarily clear the P513 fault, but if the underlying condition that triggered sump protection has not been corrected, the error will return and compressor damage could result. It is strongly recommended to have a qualified technician diagnose the root cause before resetting and restarting the unit. Running the compressor with diluted or insufficient oil can cause permanent compressor failure.

Repair costs vary widely depending on the root cause. If the fault is due to refrigerant migration after a shutdown in cold weather and no parts are damaged, a service call to diagnose and restart the system may cost in the range of $100 to $250. If the crankcase heater has failed, parts and labor could run $150 to $400. If the compressor has suffered oil-related damage, replacement costs can range from $800 to over $2,000 depending on the unit size and labor rates.