H4 is displayed; unit may not respond to commands or may lock out compressor operation.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety warning: Inverter circuits carry high DC voltages. Only experienced persons should work inside inverter-driven units.
Basic steps:
- Power reset: Unplug the unit for at least 10 minutes, then reconnect and test.
- Inspect wiring: If accessible, check the harness between the main control PCB and the inverter/compressor module for loose or damaged connectors.
Professional service: H4 typically requires a technician to test the inverter PCB and inverter compressor. Do not attempt to probe live inverter circuits without proper training and equipment.