LG Heat Pump Error Code E412

E412 means the compressor has been shut down by the low pressure sensor protection control at its third trigger level. The refrigerant circuit pressure on the suction side has dropped below the safe operating threshold, and the system locked out the compressor to prevent damage. This is not a minor or transient fault given that it has reached protection level 3, meaning the condition was persistent or severe enough to require a full shutdown.

No, you should not attempt to force the unit to continue running while E412 is active. The system has already shut the compressor down as a protective measure to prevent internal damage from low pressure operation. Running the compressor with insufficient refrigerant pressure can cause overheating, loss of lubrication, and ultimately compressor failure, which is a much more expensive repair.

A power reset may temporarily clear the fault and allow the unit to restart, but because E412 has reached protection level 3, the underlying low pressure condition is likely to trigger the code again quickly. Resetting without addressing the root cause risks further damage to the compressor. A proper repair addressing the cause of the low pressure condition is needed for a lasting resolution.

Some basic checks, such as inspecting and replacing air filters or clearing debris blocking the outdoor or indoor coils, can be done without special tools. However, diagnosing and correcting refrigerant charge issues requires EPA certification and professional gauging equipment. Because E412 is a compressor protection fault related to refrigerant pressure, it is strongly recommended to have a licensed HVAC technician complete the diagnosis and repair.

Repair costs vary widely depending on the root cause. A refrigerant recharge without a leak repair may cost between $150 and $400, while locating and repairing a refrigerant leak can range from $200 to $600 or more depending on the leak location. If the low pressure sensor needs replacement, parts and labor typically run between $100 and $300. Compressor replacement, if the unit was run in a damaged state, is significantly more expensive and can range from $800 to $2,500 or higher.