LG Heat Pump Error Code E333

E333 indicates a high pressure sensor breakaway on your LG heat pump. The control board has lost the signal from the high pressure sensor, which monitors refrigerant pressure on the discharge side of the compressor. The system shuts down to prevent unsafe operation without this critical measurement. The fault is most often caused by a loose connector, damaged wiring, or a failed sensor.

No, you should not attempt to run the system while E333 is active. The high pressure sensor is a key safety component, and operating the heat pump without a valid pressure reading risks compressor damage or unsafe pressure conditions in the refrigerant circuit. Leave the system off until the fault is diagnosed and repaired.

A power reset may temporarily clear the fault display, but if the underlying cause is still present, the E333 error will return once the system attempts to operate. Resetting without fixing the sensor connection, wiring, or faulty sensor will not resolve the problem. A proper diagnosis of the sensor circuit is needed to permanently clear the fault.

Some causes of E333 are accessible to a knowledgeable DIYer, such as reseating a loose sensor connector or inspecting the wiring harness for visible damage. However, if the sensor itself needs testing or replacement, or if the refrigerant circuit needs to be accessed, a certified HVAC technician should handle the repair. Working around high pressure refrigerant lines requires proper training and equipment.

Repair costs depend on the root cause. If only a connector needs to be reseated or cleaned, the cost may be limited to a service call fee, typically in the range of $75 to $150. If the high pressure sensor requires replacement, parts and labor combined can range from $150 to $400 or more depending on the model and technician rates. Control board replacement would be on the higher end of repair costs.