Safety: Disconnect power before accessing internal components. Refrigerant system work must be done by a certified technician.

Check cabinet temperature: Verify that the freezer or ice compartment is reaching the set temperature using a thermometer. If the main freezer is warm, the issue is not limited to the ice maker.
Inspect ice maker fan: Locate the dedicated ice maker/evaporator fan (if equipped). Spin the fan blades by hand with power off; they should move freely. If seized or noisy, replace the fan motor.
Check airflow: Ensure vents around the ice maker evaporator are not blocked by ice buildup or packaging.
Thermistor test (advanced): Locate the ice maker evaporator sensor (thermistor). Disconnect and measure resistance at known temperatures (e.g., ice water ~0°C). Compare to Miele specs; replace if out of range.
Refrigerant suspicion: If the fan runs, sensor is good, but the evaporator never frosts and F12 persists, there may be a sealed system leak or compressor issue. This requires professional service.

Warning: Do not attempt to pierce, cut, or solder any refrigerant lines yourself.

Ice maker shows F12, no ice production, water present in reservoir or tray but no freezing

Possible Causes