Miele tumble-dryer F21 error code
F21 means drying temperature sensor. The drying-level or drum temperature sensor is out of range, so the program aborts..
Often fixable at home · Fault type: Electrical/hardware
Safe checks, in order of likelihood
- Clean the fluff filters and check the condenser unit (on condenser models).
- Switch the dryer off, wait 10 minutes, and restart.
- If F21 returns, book an engineer — Miele sensors are inside the cabinet.
Call a professional when…
Reset and clean; then the sensor is replaced by an engineer. If the code returns after these checks, book a qualified engineer.
Parts usually involved
- Miele dryer temperature sensor (fitted by a Miele engineer).