LG Heat Pump Error Code E505

E505 indicates that the LG heat pump has detected a full refrigerant leakage condition at the outdoor unit. The system has determined that refrigerant charge is critically depleted, which prevents normal heating or cooling operation. This is not a sensor glitch or minor fault. It signals a real loss of refrigerant that requires a certified technician to diagnose and repair.

No, you should not continue operating the unit. Running a heat pump with a full refrigerant loss can cause the compressor to overheat and fail due to the lack of refrigerant cooling and lubrication. Compressor replacement is significantly more expensive than leak repair, so shutting down the system promptly is the best way to avoid additional damage.

Resetting the unit will not clear E505 on a permanent basis if the underlying refrigerant loss has not been corrected. The fault will return as soon as the system attempts to operate and detects insufficient refrigerant pressure. The error can only be resolved after the leak is repaired, the system is properly recharged, and refrigerant pressures return to the specified operating range.

Refrigerant work is regulated under EPA Section 608 and must be performed by a certified technician. A proper repair involves leak detection, repairing the source of the leak, pressure testing with nitrogen, evacuation, and then recharging with the correct refrigerant type and quantity. Attempting to recharge without finding and fixing the leak will only result in the refrigerant escaping again and repeated fault codes.

Repair costs vary widely depending on where the leak is located and how much damage has occurred. A straightforward flare connection repair and recharge might range from $200 to $600, while a leaking coil or compressor replacement can push costs into the $1,000 to $3,500 range or higher. Getting a full diagnostic from a licensed HVAC technician before committing to repairs is strongly recommended.