Display shows F2 and the Melitta coffee machine stops brewing shortly after starting.

Safety first: Unplug the machine and let it cool for at least 30 minutes. The thermoblock and boiler can remain hot.

Basic actions:

• Power cycle: Disconnect from mains for 10 minutes, reconnect, and test. Temporary sensor glitches can clear.
• Check for overheating signs: Smell for burnt odors and look through ventilation slots for discoloration around the heater area. If you see melted plastic or charring, do not power the unit again—contact service.
• Ventilation: Ensure the machine has adequate airflow around it. Overheating can stress the NTC sensor.

Advanced checks (for experienced DIYers):

• Remove the top and side covers. Locate the thermoblock or boiler assembly and identify the small NTC sensor clipped or screwed to it.
• Check that the NTC plug is firmly seated on the control board and at the sensor. Look for broken or pinched wires.
• If you have a multimeter, measure the NTC resistance at room temperature and compare with Melitta service data (typically in the tens of kΩ). An open circuit or short indicates a failed sensor.

If the NTC sensor tests bad, replace it with the correct Melitta boiler/thermoblock sensor. If the sensor is good but F2 remains, the control board may be faulty and should be replaced or serviced by a professional.