FixByModel
F43

Bosch F43: Drum not turning, drive/motor fault

The washer sensed that the drum is not rotating when it should, pointing at the drive motor or its wear parts. It is closely related to F21 and usually needs professional diagnosis.

May need a technician

By the FixByModel editorial team · Verified 2026-09 · Researched against manufacturer support & repair references (below)

Most likely causes

  1. Worn motor carbon brushes preventing the motor from driving the drum
  2. Seized or failed drive motor
  3. Drum physically jammed by a foreign object
  4. Broken or slipping drive belt (on belt-driven models)
  5. Damaged motor wiring or a fault in the motor control circuit
Before you start — unplug the appliance and turn off the water supply. You'll be working near water and electrical parts, and drained water can be hot. If a step involves the pump, wiring, or opening the cabinet and you're unsure, stop and call a qualified technician.

Step-by-step fix

1Unplug the washerDisconnect power before inspecting the drum or drive components.
2Turn the drumRotate the drum by hand to check it moves freely and is not blocked by a trapped item.
3Check the beltOn belt-driven models, look through the rear panel for a belt that has slipped off or snapped.
4Reset and observeRestore power and start a cycle, watching whether the drum attempts to turn at all before F43 appears.
5Book a technicianIf the drum is free but F43 persists, have the carbon brushes and drive motor tested and replaced as needed by a qualified engineer.

Still showing F43?

If you’ve worked through every step and F43 keeps returning, an internal part likely needs testing and replacement. That’s a job for a qualified appliance technician, who can measure the suspect part against the service-manual spec before replacing it.

Which models this applies to

Bosch washing machines. Bosch washers with digital fault display; F43 flags a drive/rotation fault, often alongside worn motor brushes.

FAQ

What does Bosch F43 mean?

Drum not turning, drive/motor fault. The washer sensed that the drum is not rotating when it should, pointing at the drive motor or its wear parts. It is closely related to F21 and usually needs professional diagnosis.

What causes Bosch F43?

The most likely cause is worn motor carbon brushes preventing the motor from driving the drum. Other causes include Seized or failed drive motor; Drum physically jammed by a foreign object; Broken or slipping drive belt (on belt-driven models); Damaged motor wiring or a fault in the motor control circuit.

Can I fix Bosch F43 myself?

Some checks are DIY, but this code often points to an internal component, so it may need a qualified technician.