What this error means
Heater fault — the heating element has failed or the heating circuit has an electrical fault
The F20 error means the control board has detected a fault in the heating circuit — either the element has failed to heat within the expected time, it has developed an open circuit, or an earth leakage fault has been detected. F20 is specifically an element fault — if the temperature sensor has failed the machine typically displays F29. F20 can also be triggered by heavy limescale on the element causing abnormal current draw.
What you'll need first
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Step-by-step
Symptoms to look for
- Door glass feels cold or barely warm during a 60 or 90-degree programme
- Laundry comes out at room temperature after a hot programme
- F20 displayed partway through a wash programme
- Programme runs far longer than the estimated time on the display before faulting
Diagnostic steps
Unplug for 5 minutes, plug back in and run a 60-degree programme with 2 to 3 items. After 15 minutes place your hand flat on the door glass — it should feel noticeably warm to hot. If the glass remains completely cold the element is not heating at all.
Add a Miele-approved descaling tablet or a suitable washing machine descaler to the empty drum and run a full 90-degree empty cycle. In hard water areas limescale coats the Miele element rapidly and causes abnormal current draw that the control board flags as F20. Miele recommends descaling every 1 to 3 months depending on water hardness.
With the machine completely unplugged, remove the rear panel by undoing the screws around its edge. The element is the U-shaped metal bar at the lower rear of the drum casing with two spade terminals and a small NTC thermistor sensor clipped nearby.
Disconnect the wiring from both element terminals. Set a multimeter to resistance. Touch one probe to each terminal. A healthy Miele washing machine element reads between 20 and 50 ohms. A reading of zero (short circuit) or OL (open circuit) confirms the element has failed.
Inspect the wiring loom connecting the element terminals to the main harness. Look for burnt insulation, chafed wires near the drum casing, corroded spade connectors, or terminals not fully engaged. Disconnect and firmly reconnect each connector.
Miele replacement elements are available from authorised Miele parts suppliers. Fit the replacement and reconnect all wiring. Run a 60-degree test cycle after replacement to confirm F20 has cleared.
When to call an engineer
- Element resistance is outside 20 to 50 ohms — element has failed
- Element shows continuity between a terminal and earth — earth leakage fault, replace immediately
- F20 persists after descaling and full reset — element must be replaced
- Wiring connector to element is burnt or melted — wiring loom replacement required
Frequently asked questions
What is the difference between F20 and F29 on a Miele washing machine?
Can limescale cause F20 on a Miele machine?
Is an earth fault on the heating element dangerous?
Should I use Miele's own descaling products?
🎯 What is likely causing this fault?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
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Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| Heating Element | £20 - £30 | 🛒 Amazon UK → |
| Heating Element | £18 - £25 | 🏷️ eBay UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.