Tumble Dryer
F20
The F20 error code on a Miele tumble dryer indicates a fault with the heating system — specifically that the appliance is not reaching or maintaining the correct temperature. It’s one of the more common Miele fault codes and, depending on the cause, can often be resolved without a call-out.
What does this error mean?
F20 means the dryer’s control board has detected that the drum is not heating up as expected within a set time. Miele dryers monitor temperature continuously using a thermistor (temperature sensor); if the reading is too low or absent, the machine throws F20 and stops to prevent damage. This is essentially the machine telling you: ‘I’m trying to heat, but something isn’t working.’
Est. repair cost
£80–£180 professional repair; £15–£50 DIY part (element, thermal fuse, or thermistor) if self-fitting
🔍 Likely causes
🛠️ Step-by-step fix
Reset the dryer first: switch it off at the wall, wait 30 seconds, then turn it back on and start a test cycle. A temporary sensor glitch can trigger F20 and a hard reset clears it.
Clean the lint filter thoroughly — remove it, rinse it under the tap, and let it dry completely before reinserting. A clogged filter is the single most common cause of heating faults on Miele dryers.
Clean the condenser unit (if your model has one): locate the condenser behind the bottom panel, remove it, and rinse it gently under cold running water. Blocked condensers severely restrict airflow. Consult your manual for exact access steps.
Check the appliance’s external exhaust vent (vented models): go outside and confirm the vent flap opens freely and is not blocked by debris, a bird’s nest, or a crushed hose. A blocked vent causes rapid overheating and trips the thermal cut-out.
If the drum spins but produces no heat at all after cleaning, the heating element or thermal fuse has most likely failed. These parts are replaceable — a competent DIYer comfortable working with unplugged appliances can source and fit them — but if you are unsure about working inside the machine, stop here and call an engineer.
Do NOT attempt to bypass or jump any thermal fuse, thermistor, or safety cut-out. These components exist to prevent fire. Bypassing them is dangerous and will void any remaining warranty.
📞 When to call a professional
Call a Miele-approved or reputable independent appliance engineer if the error returns after cleaning all filters and vents, or if the machine produces no heat whatsoever on a fresh cycle. Tell the engineer: ‘My Miele tumble dryer is displaying F20 — I’ve cleaned the filters and condenser, it still won’t heat.’ This tells them immediately to focus on the element, thermal fuse, thermistor, or PCB, saving diagnostic time and your money.
⚖️ Repair or replace?
A professional repair for F20 typically costs £80–£180 depending on the faulty part — a heating element or thermal fuse is at the cheaper end, a PCB at the higher. Miele dryers are built to last 10–15 years, so if your machine is under 8 years old, repair is almost always the better value. If it’s over 10 years old and the PCB or heat pump compressor has failed, replacement becomes financially sensible — a new mid-range Miele condenser dryer starts at around £800.