Miele F20 fault codewhat it means and how to fix it
Miele publish two readings of F20: the Thermostop pausing the programme until the water is at temperature, which is not a fault, and a genuine heating fault with a two-minute power-off before booking.
Take care
What F20 means
Miele’s F20 page gives two causes and they are very different things. The first is the Thermostop. Miele explain it as the function that ensures the set programme temperature is reached: it starts if the set temperature has not been reached within the specified time, the time-left display pauses while it runs, and as soon as the required temperature is reached the programme resumes and the countdown starts again. Read that carefully, because it means a machine that shows this and then carries on has not broken — it has waited for the water to get hot and then continued. The second cause is what most people fear: a technical fault with the heating.
For that, Miele do not send you straight to an engineer. Their instruction is to disconnect the machine from the electricity supply — switch off at the wall and withdraw the plug, or disconnect the fuse — wait at least two minutes before reconnecting, switch on again and restart the programme, and only if the fault persists to contact Miele or book a repair.
On machines with a text display the same fault reads as the words "Heating fault", a display string in its own right and worth knowing if you are searching for one and finding the other. Miele publish nothing about which part has failed when the reset does not clear it; the element and its sensor are inside the cabinet and neither is an owner part.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Thermostop holding the programme | Miele’s first published cause. The programme has paused because the set temperature was not reached within the specified time; it resumes when it is. Not a fault. | Common |
| Fault with the heating | Miele’s second published cause, in their words "a technical fault, there is a fault with the heating". They give a two-minute disconnect first and a repair booking if it persists. | Common |
| Very cold incoming water on a short programme | Our reading of the Thermostop description rather than anything Miele say: a long heat from very cold mains water is the ordinary reason a set temperature is not reached in the specified time. | Occasional |
What to try yourself
If the display shows F20 or "Heating fault" while the time-left display is paused and the machine is otherwise running, leave it alone for a while. Miele say this is the Thermostop waiting for the water to reach temperature, and the programme resumes on its own once it does.
If the programme has stopped and will not continue, do Miele’s reset: disconnect the machine from the electricity supply — switch off at the wall and pull the plug, or disconnect the fuse — and wait at least two minutes before reconnecting.
Switch the machine on again and restart the programme.
If F20 comes back, book a Miele engineer. Miele publish one reset for this code and nothing further to try.
If the machine has also started tripping the RCD or a breaker, stop using it and book rather than resetting the electrics each time. That advice is ours, not Miele’s.
Get a qualified appliance engineer to look at your Miele F20
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified appliance engineer, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What it costs to fix
Typical repair cost
£0–£240
Time on site
10 minutes
Nothing if the Thermostop was doing its job or the reset clears it. A heating element replaced by a Miele engineer is typically £150 to £240 including labour; a sensor is at the lower end.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Miele fault codes
- F11Get it checkedThe drain is restricted. Miele publish a maximum drain height of one metre, and they warn that straightening a kinked hose can weaken it enough to split later.Related: same brand
- F10Get it checkedWater is not getting in. Miele point at the stopcock and the inlet filter, and both are owner jobs on their own guidance.Related: same brand
- F34Get it checkedThe door could not be locked. Miele’s manual says close the door again and restart; their website adds an overloaded drum and a two-minute power-off. Try those before calling.Related: same brand
- F138Get it checkedThe Waterproof system has found water in the floor tray. Close the stopcock and unplug — the drain pump keeps running until you do.Related: same brand
- Three dashes on displayGet it checkedMiele publish two completely different meanings for three dashes. On the website it is a water leak; in the manual it is the wifi being off. The indicator lights tell you which.Related: same brand
- F41Get it checkedAn electronic module fault — but the only one of them where Miele publish an owner step. Switch off, wait about ten seconds, switch back on.Related: same brand
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Related guides
Common questions about Miele F20
My display says "Heating fault" rather than F20.
Same thing. Miele machines with a text display spell the fault out in words; machines with a segment display show the number. Both are Miele’s own published display strings for this code.
The time display has stopped counting down. Is that the fault?
Not necessarily. Miele describe exactly that as the Thermostop: the time-left display pauses while the machine waits for the set temperature, and starts running down again once it gets there. If the programme then finishes, nothing needs doing.
Can I keep using it if it still washes?
Miele do not say. A machine that clears F20 after their two-minute reset and completes a programme is, on their page, back in use. One that keeps returning F20 has a heating fault they ask you to book.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer support portal
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.