LG Air Conditioner Error Code CH08

CH08 indicates a malfunction in the indoor unit's expansion valve. This is the component that regulates refrigerant flow into the evaporator coil. The error is triggered when the control board detects an abnormality in the valve circuit, which may involve the valve coil, the wiring harness, or the valve body itself. The system may stop cooling effectively while this fault is active.

Running the unit while CH08 is active is not recommended. A malfunctioning expansion valve can cause the evaporator coil to ice over, restrict airflow, and potentially stress the compressor due to abnormal refrigerant flow conditions. Continued operation may lead to more extensive and costly damage to the refrigerant circuit.

Repair costs vary depending on what has failed. Wiring repairs or connector replacements are generally on the lower end, potentially ranging from $75 to $200 including labor. Replacing the electronic expansion valve coil or the complete valve assembly, especially if refrigerant recovery is required, can bring total costs into the $300 to $700 range or higher depending on the system and local labor rates.

Basic wiring checks, such as inspecting the connector between the PCB and the expansion valve for looseness or corrosion, can be performed by a knowledgeable DIYer. However, replacing the expansion valve itself often requires recovering the refrigerant charge, which must be done by a certified HVAC technician. Attempting refrigerant-side repairs without proper equipment and certification is unsafe and illegal in many jurisdictions.

A power reset may temporarily clear the fault display, but if the underlying expansion valve problem persists, the CH08 code will return once the system attempts to operate. A reset alone does not repair a faulty coil, seized valve, or damaged wiring harness. Proper diagnosis and repair of the root cause are needed for a lasting resolution.