F21Serious
Miele Washer F21 Error Code
A water leak has been detected by the aquastop system, and the washer has shut off water intake to prevent flooding.
Common causes
- Water leak from hose or internal component
- Faulty aquastop sensor
- Moisture in base tray
How to fix it
- Check for visible leaks under and around washer
- Dry any moisture in the base tray
- Inspect hoses for cracks or loose connections
- Reset error by turning power off for 10 minutes
⚠ When to call a pro: If error persists after drying and no visible leak, aquastop sensor or hose may need replacement.
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Always unplug the appliance (and turn off the water for washers/dishwashers) before inspecting. These guides are for information only and are not a substitute for a professional repair.