Indoor unit shows F7, abnormal heating or cooling performance

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

Incorrect indoor unit model paired with outdoor unit, Firmware mismatch between indoor and outdoor PCBs, Outdoor PCB limiting compressor frequency due to protection, Incorrect DIP switch or configuration settings

How to Fix / Troubleshooting

Safety first: Turn off power before accessing control boards.

Verify model pairing: Check that the indoor and outdoor units are compatible Tosot models as per the installation manual.
Check configuration: Some Tosot systems use DIP switches or jumpers to set capacity or mode. Verify settings match the installed combination.
Power reset: After correcting any configuration issues, power cycle the system.
If F7 persists: A technician may need to update or replace one of the PCBs to match firmware or replace mismatched equipment.

Repair Difficulty

Hard 4/5

Required Part

Outdoor Main Control Board

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