Miele Refrigerator Error Code F111

Error code F111 on a Miele refrigerator indicates that the freezer air NTC (Negative Temperature Coefficient thermistor) is reading outside its valid operating range. Specifically, the resistance value reported by the sensor corresponds to a temperature below -66°F (-55°C) or above 140°F (60°C). Because both of these extremes fall well outside any realistic freezer operating condition, the control board interprets the reading as a sensor fault rather than an actual temperature condition. The NTC thermistor works by changing its electrical resistance as temperature changes, and the control board calculates temperature by measuring that resistance. When resistance drops too low or climbs too high, the system flags the sensor as faulty.

The freezer air NTC is responsible for monitoring the air temperature inside the freezer compartment. This reading is used by the control board to regulate compressor cycling, fan operation, and defrost timing. A failed or out-of-range sensor can cause the refrigerator to behave erratically, including continuous compressor operation, failure to cool, or improper defrost cycles, depending on how the control board responds to the fault condition.

The most common root cause is physical failure of the NTC sensor itself, where the thermistor element has degraded or broken internally, producing an open or shorted circuit. Wiring issues between the sensor and the control board can produce the same out-of-range readings. Less commonly, moisture ingress or ice buildup around the sensor can affect its readings, though a true wiring or sensor failure is the more typical cause of an F111 fault.