: Communication Error . This is one of the most common codes, signifying a communication failure between the indoor and outdoor units. It often requires a technician to check for loose wiring or a faulty PCB.

: Compressor Overheating . The discharge pipe temperature is too high.

: Indoor Temperature Sensor Error . This usually indicates an open or closed circuit in the indoor air thermistor.

: Outlet Pipe Sensor Error . A fault with the indoor unit's outlet pipe thermistor.

: Communication Error . Specifically between the evaporator and condenser units. Quick Troubleshooting Steps Troubleshooting LG AC CH05 Error: A Quick Guide - Ftp