LG Heat Pump Error Code E555

E555 indicates a full leakage of refrigerant detected in the outdoor unit of your LG heat pump. The system monitors compressor operating current and refrigerant pressure simultaneously, and when both drop to critically low levels, E555 is triggered. The unit shuts down to protect the compressor from running without adequate refrigerant lubrication and cooling. A certified HVAC technician is required to diagnose the leak source, repair it, and restore the refrigerant charge.

No, you should not attempt to operate the heat pump while E555 is active. Running a compressor with little or no refrigerant causes rapid wear and overheating of the compressor internals, which can result in complete compressor failure. The system is designed to shut itself down when this condition is detected specifically to prevent that kind of damage. Leave the unit off until a technician has repaired the leak and recharged the system.

Repair costs for an E555 fault can vary widely depending on the location and extent of the refrigerant leak. A minor leak repair combined with refrigerant recharge might fall in the range of $300 to $700, while a more serious leak involving damaged line sets or coil replacement could run $800 to $2,000 or more. If the compressor has already been damaged from running without refrigerant, total repair costs including compressor replacement could be significantly higher. Getting a diagnostic assessment from a licensed technician before committing to repairs is strongly recommended.

No, E555 cannot be resolved without professional service. Refrigerant handling, leak detection, evacuation, and recharging require EPA Section 608 certification and specialized equipment. You can visually inspect accessible line sets and the outdoor unit for obvious physical damage, but any repair involving the refrigerant circuit must be performed by a licensed technician. Attempting to add refrigerant without first finding and repairing the leak will not solve the problem.

Resetting the heat pump may temporarily clear the E555 code from the display, but the fault will return almost immediately if the refrigerant charge has not been restored. Because the system actively monitors compressor current and refrigerant pressure during operation, it will re-detect the low-refrigerant condition as soon as the compressor attempts to run. A reset does not address the underlying problem and should not be used as a workaround.