F21
Miele
Temperature Regulation Fault
Display shows F21; freezer temperature too low or unstable; food may be excessively frozen or frosted.
Advertisements
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.
Advertisements
Possible Causes
Stuck relay on control board causing continuous compressor operation, Faulty temperature sensor calibration, Control board logic error
How to Fix / Troubleshooting
Safety: Disconnect power before accessing control electronics.
Steps:
- Verify setpoints: Confirm that the temperature settings are correct and that SuperFreeze/SuperCool functions are not left on.
- Power reset: Unplug for 10 minutes, then reconnect and monitor temperatures with a thermometer.
- Check sensor readings: If you have access to service mode (per Miele documentation), compare displayed sensor values to actual temperatures.
If the compressor runs excessively and temperatures remain too low despite correct settings, the control board or sensor may need replacement by a professional.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Main Control Module or Compartment Temperature Sensor
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements