Indoor unit displays F6; the compressor may not start or may shut down quickly.

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

Inverter PCB unable to drive the compressor at low frequency, DC bus voltage instability, Compressor mechanical issue at low speed, Faulty current sensor on the outdoor PCB.

How to Fix / Troubleshooting

Safety first: Only qualified personnel should work inside the outdoor control box. Disconnect power and wait for DC bus capacitors to discharge.

Visual inspection: Open the outdoor control box and inspect the inverter PCB for burnt components, bulging capacitors, or discoloration.
Check wiring to compressor: Ensure all compressor terminals and harnesses are tight and undamaged.
Power reset: Restore power after 10 minutes and test operation. If F6 reappears, the inverter PCB or compressor may be faulty.
Professional diagnosis: A technician should measure DC bus voltage, compressor winding resistance, and insulation. Replace the inverter PCB or compressor as indicated.

Repair Difficulty

Professional Required 5/5

Required Part

Outdoor Inverter Control Board

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