Thermador DEF error code

The defrost heater or its thermostat has failed, letting frost accumulate on the evaporator — we test and replace as needed.

Because a code points to a likely area rather than an exact part, we run a full on-site diagnosis to confirm the real cause — testing the components above and the wiring and controls behind them. You get a clear, flat-rate quote before any work begins, and most DEF faults are resolved on the first visit with quality parts and a parts-and-labor warranty.