LG Air Conditioner Error Code 27

Error code 27 on an LG air conditioner indicates a PFC fault due to an AC input instantaneous over-current event. The inverter PCB detected input current exceeding 100 amps peak for 2 microseconds and triggered a protective shutdown. This protects the inverter board and compressor from damage caused by the abnormal current spike. The fault is most often related to supply voltage problems or wiring issues rather than a failed component.

No, you should not attempt to continue operating the unit while error code 27 is active. The unit shuts down automatically when this fault is detected to prevent damage to internal components. Repeatedly resetting and restarting the system without resolving the underlying cause can lead to further damage to the inverter PCB or compressor. The electrical conditions that trigger this fault can also indicate a wiring issue that poses a safety risk.

Repair costs vary depending on the cause. If the fix involves tightening wiring or correcting the supply circuit, labor costs alone may apply, typically in the range of $75 to $200 depending on the technician and region. If the inverter PCB requires replacement, parts and labor combined can range from $300 to $700 or more depending on the unit model and parts availability. Getting a diagnostic assessment before committing to a repair is strongly recommended.

Some causes of error code 27 can be addressed without replacing parts, such as tightening loose wiring connections or correcting an inadequate power supply circuit. However, working on AC input wiring and inverter boards involves high voltage and should only be performed by a qualified technician. If the issue lies with the inverter PCB itself, professional diagnosis and component replacement are required.

A power reset may temporarily clear the fault display, but if the underlying cause has not been corrected, the error will return once the unit attempts to operate again. Resetting without diagnosis does not fix the root problem and may delay proper repair. A thorough check of input voltage, AC wiring, and compressor connections should be completed before restarting the system.