Miele Dryer Error Code F3

The F3 error code on a Miele dryer indicates a short circuit condition in the fill ring temperature sensor, designated internally as 1R30. This sensor monitors the temperature at the fill ring, a component positioned in the airflow path of the dryer drum. When the control board reads a resistance value from the sensor that corresponds to temperatures above 320 degrees Fahrenheit (160 degrees Celsius), it interprets this as an out-of-range short circuit condition and triggers the F3 fault. The key distinction here is that the fault is electrical, not necessarily a genuine overtemperature event. A short circuit in the sensor circuit pulls resistance down to abnormal levels, which the control interprets as an extremely high temperature reading.

The most immediate diagnostic focus should be the wiring harness and connector plug associated with the 1R30 sensor. Short circuits most commonly develop at connection points due to pinched wiring, heat-related insulation breakdown, or moisture intrusion into the plug. The sensor itself can also fail internally, producing a short across its terminals. Because the control board uses resistance values to calculate temperature, any direct or near-direct path between the sensor leads will register as a dangerously high temperature and shut the dryer down as a safety precaution.

Proper diagnosis requires isolating the sensor circuit by disconnecting the plug at the 1R30 sensor and measuring resistance across the sensor terminals as well as checking for continuity between each lead and the dryer chassis ground. A shorted sensor will typically show near-zero resistance rather than the expected resistance range for ambient temperature. If the wiring checks out but the fault persists after reconnection, the sensor itself is the likely replacement candidate.