f21
Moderate
Bosch · Washing Machines
Motor control system malfunction
Quick Answer
Error code F21 on your Bosch Washing Machines means: Motor control system malfunction. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Check if the drum rotates freely by hand.
2
Test the tachogenerator for proper operation.
3
Inspect the motor carbon brushes.
4
Check the control board for a shorted triac.
5
Replace the faulty component (motor, tachogenerator, or control board).
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Motor carbon brushes
Tachogenerator
Control board
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