Bosch dishwasher E21 error
Stop using the machine
The circulation pump that drives water up to the spray arms is reported as blocked, so the machine stops rather than running the motor against an obstruction. Debris that has passed the filters has reached the circulation pump and is fouling the impeller is the most common cause.
- Difficulty
- Technician job
- Time needed
- About 30 min
- Checks
- 5 steps
The same fault is shown as E6002 on some Bosch series, depending on the display and the model year.
Before you start
- Isolate the machine at the socket before reaching into the sump. Glass fragments are common here and the pump is mains driven.
- Do not lay the machine on its side or remove the base panel to reach the circulation pump. It sits alongside mains wiring beneath a tub that still holds water.
- Do not run the programme repeatedly hoping it clears. Driving a pump against a blockage is what turns a jam into a failed motor.
What it means
The circulation pump that drives water up to the spray arms is reported as blocked, so the machine stops rather than running the motor against an obstruction.
Most likely causes
Ordered from most to least common, with what each one looks like:
| Cause | How likely | What you would see |
|---|---|---|
| Debris that has passed the filters has reached the circulation pump and is fouling the impeller | high | The filters were found blocked or missing, letting solids straight through to the pump |
| Glass fragments from a breakage in a previous cycle have worked their way into the pump housing | medium | Something broke in the machine recently and the pieces were never all accounted for |
| A build-up of scale and hardened grease has seized the impeller after long service in hard water | medium | The tub shows heavy chalky deposits and the machine has never been descaled |
| The circulation pump motor or its control circuit has failed | low | The code persists after the filters and sump have been proven completely clear |
Fix steps
Tools needed
- Gloves
- Torch
-
Switch the dishwasher off at the socket or fused spur and leave it isolated while you inspect it.
Expected result The display is dark and no part of the machine can be driven while your hands are inside it.
-
Remove the filter assembly and check whether it was correctly fitted and locked, since an unlocked filter is the usual route for debris to reach the pump.
Expected result You can tell whether the filters have been letting solids through.
-
Clean the filters thoroughly, sweep the sump with a gloved hand and a torch, and remove every fragment you find.
Expected result The sump and filter housing are completely clear of debris and glass.
-
Refit and lock the filters, restore power and run a short rinse programme, listening for the circulation pump at the wash stage.
Expected result The pump runs smoothly, the arms spin, and the code does not return. If it does not, go to step 5.
-
If the code comes back, stop and book an engineer. The circulation pump sits under the tub and is not reachable without dismantling the machine.
Expected result The engineer arrives knowing the sump is clear and that the pump itself needs attention.
Parts needed
| Part | Part number | Typical cost |
|---|---|---|
| Circulation pump | Varies by model | Varies by supplier |
When to call a technician
Call a qualified technician for this one. The steps above are safe to carry out yourself to confirm the fault, but the repair involves work that should not be attempted without the right training and equipment.
Common questions
What does E21 mean on a Bosch dishwasher?
The circulation pump that drives water up to the spray arms is reported as blocked, so the machine stops rather than running the motor against an obstruction. Debris that has passed the filters has reached the circulation pump and is fouling the impeller is the most common reason for it.
Can I keep using the dishwasher?
No. Stop using the machine until the fault is resolved, because running it in this state risks further damage or a water leak.
Is this something I can fix myself?
No. This one should go to a qualified technician. You can safely carry out the first checks below to confirm the fault, but the repair itself is not a DIY job.
Models this applies to
- SMS All codes for this model
- SMV All codes for this model
- SMI All codes for this model
- SHP All codes for this model
- SHE All codes for this model
Related codes on the same machines
- E12 Limescale and grease have built up on the heating surfaces to the point where the machine reports that it needs descaling before it can heat water reliably.
- E15 Water has collected in the tray underneath the dishwasher and a float in that tray has tripped the leak protection system, which shuts the machine down and runs the drain pump to keep the leak from spreading.
- E18 The machine asked for water and not enough arrived in the time it allows, so it stopped the cycle rather than washing without a proper fill.
- E22 The filters in the base of the tub are blocked enough to starve the circulation pump, or the filter assembly is not locked into place, so the machine cannot move water round the wash arms properly.
- E23 The machine has detected a fault in the waste water pump circuit.
- E24 The dishwasher tried to pump the water out and the level in the tub did not drop, so it stopped mid-cycle with dirty water still standing in the bottom.
Sources
- BSH Hausgeraete GmbH (Bosch), Bosch dishwasher error code list, entry E21 (link) — retrieved 2026-07-26