LG Heat Pump Error Code E5

The E5 code on an LG heat pump signals a setting error involving the option switch for peripheral equipment control. It appears when the address configured on the wired remote controller does not match the RMC address set on the indoor unit. This is a configuration issue rather than a component failure, and it is resolved by verifying and synchronizing the addresses on both devices.

The E5 error is not a safety hazard. It is a configuration fault that prevents proper communication between the wired remote controller and the indoor unit, but it does not indicate an electrical or mechanical danger. The system will alert you to the mismatch and may limit operation until the address settings are corrected.

In most cases, the E5 error requires only a configuration correction and no replacement parts, so the cost is primarily a service call fee, which typically ranges from $75 to $150 depending on your location and technician. If the issue is traced to a damaged option switch or a faulty indoor unit control board, part and labor costs can range from $150 to $400 or more. Getting a diagnostic estimate before authorizing repairs is always a good idea.

To fix the E5 error, start by checking the option switch settings on the indoor unit and comparing that address to the address assigned on the wired remote control. Both addresses must match for the system to communicate correctly. The recommended approach is to reset both the indoor unit option switch and the remote controller address to '1'. If the error persists after correcting the addresses, further inspection of the control board or wiring may be needed.

A simple power reset alone is unlikely to clear the E5 error because the underlying address mismatch will remain after power is restored. The error will return unless the wired remote control address and the indoor unit RMC address are corrected to match each other. Once the addresses are properly synchronized, the error should clear.