LG Air Conditioner Error Code 11

Error code 11 means the outdoor unit cannot recognize the indoor unit. The outdoor unit sent a calling signal to the indoor unit but did not receive the required addressing signal back within 3 minutes. The system will not operate until this communication link is successfully established.

The system will not operate normally while error 11 is active because the outdoor unit cannot communicate with the indoor unit. There is no immediate safety hazard from the error itself, but you should not attempt to bypass the fault. Address the communication issue before returning the system to service.

Repair costs vary depending on the root cause. If the fix is simply correcting a wiring connection, a service call fee of roughly $75 to $150 may be all that is required. If the outdoor or indoor PCB needs replacement, parts and labor can range from $250 to $600 or more depending on the unit model and local labor rates.

A reset of the outdoor unit main PCB is the recommended first step and may clear the error if the cause is a transient software fault. After resetting, you should re-run the auto-addressing procedure. If the wiring or a PCB is physically faulty, the error will return after the reset.

Start by resetting the outdoor unit main PCB, then re-run the auto-addressing procedure. If the error persists, inspect the communication wiring between the indoor and outdoor units for loose terminals, breaks, or incorrect polarity. If the wiring is intact, the indoor or outdoor PCB may require testing and possible replacement by a qualified technician.