Bosch Washing Machine Error Code F21
Motor fault — drum not spinning or motor running abnormally
What Does Error Code F21 Mean on a Bosch Washing Machine?
Motor fault — drum not spinning or motor running abnormally.
The control detected the drum is not spinning as expected, often because the motor cannot start or maintain speed. Can be caused by a jammed drum, worn carbon brushes, or a motor/control-board fault.
What Causes Error Code F21?
Here are the most common causes in order of frequency. Start with the most likely cause before moving to the next:
- 1 Drum jammed by a foreign object 35% of cases
- 2 Worn carbon brushes 30% of cases
- 3 Drive motor winding failure 20% of cases
- 4 Motor control board fault 15% of cases
How to Fix Bosch Washing Machine Error Code F21
- 1
Check for a foreign object
Unplug the machine and try to turn the drum by hand; resistance indicates a jam.
⚠️ Unplug before reaching into the drum. - 2
Inspect carbon brushes
Worn brushes (under 10–15 mm) must be replaced on brush-motor models.
🔩 Bosch washer carbon brushes ($10–$30) - 3
Test motor windings
Measure winding resistance with a multimeter.
🔩 Multimeter - 4
Replace the motor or control board
If brushes are fine and windings are bad, replace the motor.
🔩 Bosch drive motor ($100–$250)
How to Reset Error Code F21
Unplug 5 minutes and restart; if drum is jammed, clear the obstruction first.
Note: If the error returns after resetting, the underlying issue has not been resolved. Work through the fix steps above.
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Thanks for letting us know. If the steps above didn't work, see when to call a professional.
When to Call a Professional
If carbon brushes and motor windings test good, replace the motor control board.
Related Error Codes
Same Code on Other Brands
Error code F21 appears on these other brands too. See every brand that shows F21 →
Find Replacement Parts
Use these links to find the exact replacement parts for your Bosch Washing Machine:
External links — ApplianceErrors.com is not affiliated with these retailers.
More Bosch Washing Machine Error Codes
Frequently Asked Questions
Can I keep using my Bosch Washing Machine when error F21 appears? +
What most commonly causes F21 on a Bosch Washing Machine? +
F21 keeps coming back after a reset — what should I check next? +
How much does it cost to fix Bosch Washing Machine error F21? +
Sources & References
- • Bosch Home Appliances Service — official manufacturer documentation
- • Our editorial & verification policy
Content verified against manufacturer service documentation. Last verified: June 10, 2026.