Bosch Dishwasher Error Code E21 — Circulation Pump Blocked
What this means
The E21 error indicates the circulation pump (wash pump) is blocked, jammed, or running below its expected speed. This prevents water from being sprayed through the wash arms. Common causes include debris in the pump impeller, a worn pump motor, or a foreign object lodged in the pump housing.
Step-by-step fix
3 stepsClean the filters
Remove and thoroughly clean all filters (coarse, fine, and micro) at the bottom of the dishwasher tub.
A severely clogged filter can reduce water flow to the pump enough to trigger this error.
Check the pump impeller
Remove the spray arm and filter assembly to access the pump impeller. Check for glass fragments, bones, or other debris jamming the impeller.
Wear gloves — broken glass is a common culprit and can cause cuts.
Run a test cycle
Reassemble everything and run an empty cycle. Listen for the pump running — it should produce a steady hum, not grinding or clicking.
Grinding sounds indicate the pump motor bearings are worn and the pump needs replacement.
When to call a professional
If the pump impeller is clear but the pump still doesn't run correctly, the pump motor has failed and needs professional replacement.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
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