LG Air Conditioner Error Code 204

Error code 204 on an LG air conditioner indicates a communication transmission error between the HR (Heat Recovery) unit and the outdoor unit. The two units are unable to exchange control signals properly, which causes the system to stop operating and display this fault. It points to a problem in the wiring, connectors, or control boards involved in that communication link.

No, the system will typically stop operating when error code 204 is active because the HR unit and outdoor unit cannot coordinate safely without a working communication link. Attempting to force operation could lead to incorrect system behavior. The fault should be diagnosed and resolved before resuming normal use.

A power reset may temporarily clear the error code display, but if the underlying wiring or component issue is still present, the code will return once the system attempts to re-establish communication between the HR unit and the outdoor unit. A reset alone is not a repair. The physical cause of the communication failure must be identified and corrected to prevent the fault from recurring.

A homeowner can safely check whether any accessible communication or power cable connections appear loose or visibly damaged at the unit terminals. However, diagnosing the HR unit PCB communication LED, testing wiring continuity, and replacing control boards requires technical knowledge and access to internal components. Most repairs beyond basic connection checks should be handled by a qualified technician.

Repair costs depend heavily on the root cause. If the fix is as simple as reseating a loose connector, the cost may be limited to a service call fee, typically in the range of $75 to $150. If a PCB replacement is needed for either the HR unit or the outdoor unit, parts and labor combined can range from $300 to $800 or more depending on the specific board and local labor rates.