Bosch · Washer error code

F21Motor fault

Single source High-voltage / caution

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Related diagnostic guides

Component test · Washer

How to test a universal (brushed) motor and its carbon brushes

Universal motors run on AC or DC through carbon brushes that rub on a commutator. Brushes wear out and are the most common failure. Check brush length and the commutator, then test the field and armature with a meter.

6 steps ~60 minmoderate

Component test · Washer

Washer motor control unit / inverter board

Direct-drive and inverter washers use a motor control unit (MCU) that powers a 3-phase motor and reads a hall sensor or tach. Separate MCU, motor windings, hall sensor and harness before buying a board.

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Rotor position sensor (direct-drive motors)

On direct-drive motors the rotor position sensor sits on the stator and tells the inverter where the rotor magnets are. A bad sensor, cracked connector or water ingress gives motor errors even with good windings.

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E16 / F16

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E17 / F17

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E18 / F18

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E19 / F19

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E23 / F23

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E26 / F26

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