LG Air Conditioner Error Code E164

E164 indicates an incompatible indoor unit model setting or a Fahrenheit and Celsius temperature scale conflict in the system's configuration. The indoor unit's control system cannot validate its operational parameters because the option codes stored in the remote controller are incorrect or missing. This is a commissioning or configuration error rather than a hardware fault.

E164 is a configuration error, not a safety-critical fault. The system generates this error to prevent operating with mismatched settings that could cause incorrect behavior, but it does not indicate an electrical hazard or risk of equipment damage. The unit may be restricted from normal operation until the error is resolved, but addressing the option code settings is straightforward.

If the issue is limited to incorrect option codes, a qualified technician's diagnostic and reprogramming visit typically costs in the range of $75 to $200 depending on your location and the service provider. If the remote controller has failed and cannot retain programmed settings, a replacement remote controller adds parts cost, generally ranging from $50 to $150 or more depending on the specific model required.

The fix requires accessing the remote controller's installer or service menu and verifying that the correct option codes are entered for the specific indoor unit model installed. You also need to confirm that the temperature scale setting (Fahrenheit or Celsius) matches the expected regional configuration for your unit. Once corrected, the error should clear without any component replacement in most cases.

A simple power reset will generally not clear E164 because the error is caused by incorrect or missing option codes stored in the remote controller, not a temporary fault. After a reset, the system will re-read the same invalid configuration and re-trigger the error. The option codes must be corrected through the remote controller's programming menu to permanently resolve it.