Miele Washing Machine Error Code F20 — Heating Fault
What this means
Error F20 on Miele washing machines indicates the heating element has failed to raise the water temperature to the programmed level within the timeout. Causes include a burned-out heating element, a faulty NTC sensor giving false readings that prevent the heater from activating, a tripped thermal fuse, or a control board relay failure. The machine may complete the wash cycle in cold water or may stop entirely.
Alternate codes: F 20
Step-by-step fix
4 stepsCheck if the water heats partially
Start a 60°C or 90°C wash and wait 15–20 minutes. Open the door (if the machine allows mid-cycle pause) and feel if the water is warm. Stone cold means the heater is not activating. Lukewarm means it may be activating intermittently.
The door glass temperature can indicate heating — carefully touch the lower part of the door glass after 15 minutes.
Test the heating element
Unplug the machine and remove the rear panel. Locate the heater terminals at the bottom of the drum. Disconnect the wires and measure resistance — a good heater reads between 20 and 40 ohms. Also test for ground fault (each terminal to the metal body).
The heater is secured by a large nut on a bolt in the center. Do not remove it unless you need to replace the heater.
Test the NTC sensor
The NTC sensor is often clipped into the heater housing. Disconnect it and test resistance — should be 5,000–15,000 ohms at room temperature. If it reads incorrectly, the board may not activate the heater.
A sensor reading too high tells the board the water is very cold, while too low tells it the water is very hot — both can prevent proper heating control.
Check the thermal fuse
Some Miele washing machines have a thermal fuse on the heater. Test for continuity — a blown fuse reads open-circuit. Replace if needed, but investigate the root cause of the overheat.
A blown thermal fuse often indicates a previous NTC sensor failure that let the heater run too long.
When to call a professional
If the heater, NTC, and fuse all test fine, the control board heater relay has likely failed. Board replacement requires professional service.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
Learn more about our sourcesParts you may need
Heating Element
Part #6260480 · $50–$100
If element reads open-circuit or has ground fault
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