LG Heat Pump Error Code E506

E506 on an LG heat pump signals a low pressure detection error that occurs at the initial start of the compressor. The system detected that the low side refrigerant pressure was below the minimum acceptable threshold before pump down began. This causes the unit to shut down to protect the compressor from damage. The most common cause is refrigerant that has leaked from the system.

No, you should not attempt to continue operating the heat pump with an E506 fault active. The error code indicates the compressor is being prevented from starting due to dangerously low refrigerant pressure. Running a compressor with insufficient refrigerant can cause overheating, loss of lubrication, and permanent compressor failure. Leave the unit off until a technician has diagnosed and corrected the issue.

A power reset may temporarily clear the E506 fault display, but the error will return immediately at the next compressor startup attempt if the underlying low pressure condition still exists. Because E506 is triggered by a measured refrigerant pressure that falls below a defined threshold, the fault cannot be permanently resolved without correcting the actual pressure problem. Resetting without repair is not a solution and risks repeated compressor protection shutdowns.

Diagnosing and repairing E506 requires EPA Section 608 certification to legally handle refrigerants, along with a manifold gauge set and access to LG's S-net diagnostic interface. Homeowners can check that all service valves are fully open and that no obvious physical damage is visible at refrigerant line connections, but the actual repair including leak detection, refrigerant recovery, vacuuming, and recharging must be performed by a certified technician.

Repair costs vary depending on the root cause. If the issue is only a refrigerant recharge after a minor leak is found and repaired, costs typically range from around 200 to 600 dollars depending on refrigerant type and quantity needed. If the low pressure sensor requires replacement, parts and labor may add another 100 to 300 dollars. A major leak requiring extensive brazing or component replacement can push total costs significantly higher.