LG Air Conditioner Error Code 63

Error code 63 means the control board detected an abnormally low temperature at the condenser pipe thermistor. The board monitors this sensor continuously and shuts the system down when the reading falls outside the acceptable range. Common reasons include low refrigerant, a dirty condenser coil, or a defective thermistor.

Running the unit while error 63 is active is not recommended. The error is a protection fault designed to prevent compressor damage from abnormal operating conditions such as low refrigerant pressure. Continuing to operate the system risks compressor failure, which is far more expensive to repair than the underlying cause of the error.

A refrigerant leak is one of the more common causes of error code 63 because low refrigerant pressure directly lowers condenser pipe temperature. However, a dirty condenser coil or a failed thermistor can produce the same error without any refrigerant loss. A technician with a manifold gauge set can confirm whether system pressure is within spec and rule out a leak.

Start by inspecting the outdoor condenser coil for dirt and debris and clean it if necessary. Check that the condenser pipe thermistor is properly seated and its wiring connector is secure. If those steps do not clear error 63, have a licensed HVAC technician check refrigerant pressure, since a low charge is a frequent cause and requires certified handling.

Cost depends on the root cause. Cleaning a blocked condenser coil yourself costs nothing beyond time and a water hose. Replacing a condenser pipe thermistor is typically a low-cost repair, with parts often ranging from $15 to $50 and labor adding $75 to $150 depending on your market. If the cause is a refrigerant leak, expect $150 to $400 or more depending on the type of refrigerant, the leak location, and local labor rates.