F21Serious
Bosch Washer F21 Error Code
Water not draining; drain pump blocked or faulty.
Common causes
- Lint/debris in pump filter
- Blocked drain hose
- Faulty drain pump
How to fix it
- Unplug washer
- Open filter cover (bottom right), drain water, clean filter
- Check drain hose for kinks/blockages
⚠ When to call a pro: If pump makes humming noise but won't spin, or filter clean but error persists
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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.