LG Air Conditioner Error Code 150

Error code 150 on an LG air conditioner means the outdoor unit is detecting abnormally low discharge superheat at the compressor, a condition that persists for 5 minutes or more. This indicates liquid refrigerant is returning to the compressor instead of fully vaporized gas, which is referred to as liquid back or liquid slugging. The most common source is an indoor unit with an EEV that is allowing too much refrigerant to pass through. This fault requires prompt attention to avoid compressor damage.

Continuing to operate the system with error code 150 active is not recommended. Liquid slugging can cause rapid mechanical damage to the compressor, including cracked valve reeds and bearing failure. Shutting the system down and having it inspected before resuming normal operation is the safest course of action.

A power reset may temporarily clear error code 150, but the fault will return if the underlying cause has not been corrected. Because this code activates after 5 consecutive minutes of low discharge superheat, the condition triggering it is persistent and not a random glitch. Resetting without diagnosing and repairing the cause risks further compressor damage each time the unit runs.

Some basic checks, such as verifying the system has not been recently recharged or that no installation errors occurred, can be performed by a knowledgeable DIYer. However, diagnosing and correcting the root cause typically requires accessing refrigerant pressures, testing EEV operation, and measuring pipe temperatures under specific controlled conditions. Because refrigerant handling requires EPA certification in the United States, most of this repair should be handled by a licensed HVAC technician.

Repair costs depend heavily on the root cause. If the fix involves reclaiming excess refrigerant or correcting a configuration issue, costs may range from around 100 to 300 dollars. If an indoor unit EEV needs replacement, parts and labor could bring costs to the 300 to 700 dollar range. Compressor replacement, if damage has already occurred, is significantly more expensive and can range from 1,000 to 2,500 dollars or more depending on system size.