LG HVAC Error Code E652

E652 indicates a communication error caused by more than one unit being configured as MASTER on the COM1 dual MASTER network. LG HVAC multi-unit systems require a strict hierarchy where only one unit acts as MASTER and all others are set to SLAVE. When this configuration is violated, the system cannot communicate properly and displays E652. The fix involves checking the K8 position on the SW05 option setup switch on the PCB of each connected unit.

E652 is primarily a communication configuration error rather than a safety hazard involving high-voltage or refrigerant risks. However, because the error disrupts system communication, the HVAC equipment may not operate correctly or at all while the fault is active. You should avoid running the system in a faulted state for extended periods and have a technician correct the switch configuration promptly to prevent further operational issues.

If the fix only requires reconfiguring the SW05 K8 switch on the PCB, the cost is primarily a service call and labor fee, which typically ranges from $75 to $200 depending on your location and technician rates. If the SW05 switch itself is damaged and a PCB replacement is needed, total costs including parts and labor could range from $300 to $800 or more. Getting a diagnostic quote from a certified LG HVAC technician before authorizing any parts replacement is advisable.

Fixing E652 requires accessing the PCB on each unit connected to the COM1 bus and inspecting the SW05 option setup switch, specifically the K8 position. Only one unit in the system should have K8 set to MASTER, and all other units must be set to SLAVE. Once the duplicate MASTER designation is corrected, the communication conflict should be resolved. This process typically requires a qualified HVAC technician since it involves working with internal electrical components.

A simple power reset will not permanently clear the E652 error because the underlying cause, a duplicate MASTER switch configuration, remains in place after power is restored. The system will detect the conflicting MASTER designations on the COM1 bus again and re-trigger the fault. The SW05 K8 switch on the affected unit or units must be physically corrected before the error will be resolved.