LG HVAC Error Code E202

The E202 code on an LG multi-zone or VRF system indicates a sustained MASTER-to-SLAVE communication failure. After the system completes its tracking sequence, the MASTER PCB cannot maintain contact with one or more SLAVE indoor unit PCBs for 2 consecutive minutes. This causes the system to halt operation and log the fault code.

The system will typically stop operating normally when E202 is active, so continued use is not usually possible without clearing the fault. It is not advisable to bypass or ignore the error, as unresolved communication faults can mask underlying electrical or hardware issues that may worsen over time. Contact a qualified HVAC technician for diagnosis.

Pressing RESET KEY K3 on the MASTER PCB clears the fault temporarily and restarts the tracking process, but the E202 code will return if the communication issue is not resolved. A permanent fix requires identifying and correcting the specific cause, such as repairing wiring, restoring power to affected indoor units, or replacing a faulty SLAVE PCB.

You can initiate a diagnostic reset by pressing the RESET KEY K3 on the MASTER PCB, which triggers a new tracking sequence and shows how many SLAVE units are responding. However, this reset alone will not clear the fault if the underlying communication problem persists. If any indoor units fail to respond after the reset, a technician will need to inspect wiring and PCBs at those units.

Repair costs vary depending on the root cause. If the fix involves re-terminating or replacing communication wiring, costs are generally lower, typically in the range of $100 to $300 for labor. If one or more SLAVE PCBs need to be replaced, parts and labor combined can range from $300 to $800 or more per unit depending on the model and local rates.