LG Heat Pump Error Code 34

Error code 34 means the compressor was shut down by the high pressure protection circuit three times within one hour because discharge pressure exceeded the system's allowable limit. The unit locks out after the third trip to protect the compressor from damage. A technician needs to identify and correct the cause of the elevated pressure before the system can resume normal operation.

No. The system has already locked out the compressor as a protective measure, and attempting to reset and restart it repeatedly without fixing the underlying problem risks compressor damage, which is one of the most expensive components in the system. Leave the unit off until the cause of the high pressure condition has been diagnosed and corrected.

Repair costs vary widely depending on the root cause. Cleaning a blocked outdoor coil or clearing an airflow obstruction might cost between $75 and $200 for a service visit. Replacing a high pressure sensor typically ranges from $150 to $400 including parts and labor. If the compressor has been damaged by repeated high-pressure events or a refrigerant-related issue requires extensive work, costs can range from $600 to several thousand dollars depending on the repair scope.

Some causes, such as a dirty outdoor coil or a blocked airflow path around the unit, can be addressed by a homeowner through cleaning and clearing debris. However, diagnosing refrigerant pressure issues, testing the high pressure sensor against gauge readings, and correcting an overcharge or restriction require refrigerant handling certification and specialized tools. Most repairs that get to the root of code 34 require a licensed HVAC technician.

A reset may temporarily clear the fault and allow the unit to restart, but if the root cause has not been addressed the compressor will trip on high pressure again and re-display code 34. Repeated resets without a proper repair can accelerate wear on the compressor and other refrigerant-side components. The error will return until the underlying pressure problem is resolved.