Miele Refrigerator Error Code F122

The F122 error code on a Miele refrigerator indicates that the ambient air NTC (Negative Temperature Coefficient) sensor has reported a resistance value that falls outside the acceptable operating range. Specifically, the sensor's resistance reading corresponds to a temperature below -66°F (-55°C) or above 140°F (60°C), both of which are physically impossible under normal refrigerator operating conditions. Because NTC sensors change resistance predictably with temperature, readings this far outside the expected range point to a sensor fault rather than an actual extreme temperature condition.

The ambient air NTC monitors the temperature of the air surrounding the refrigerator, which helps the control board manage compressor cycles and overall cooling performance in relation to the environment. When this sensor fails, the control system loses the ability to accurately compensate for room temperature changes, potentially affecting efficiency and cooling consistency. The fault can originate at the sensor itself, in the wiring harness connecting it to the control board, or at the connector terminals.

Common causes include a failed NTC sensor element, a broken or shorted wire in the sensor circuit, and corroded or loose connector pins that create an intermittent or out-of-range resistance reading. Because the first recommended diagnostic step is direct replacement of the ambient air NTC, sensor failure is considered the primary suspect. Technicians should also inspect the wiring and connectors for visible damage before condemning the sensor outright.