Bosch · Dishwasher

Bosch dishwasher E21 code

ErrorE21

E21 is listed by Bosch support as heat pump is blocked. The exact checks and component layout can vary by model and region.

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Source-linked guidance reviewed against Bosch US dishwasher error codes.

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What the code means

Heat pump is blocked

Do not open fixed panels or test live electrical parts. Record the full model number and arrange qualified service if the code returns after the permitted external checks.

Typical symptoms

01Water circulation may be weak or absent

02The dishwasher may hum without normal spray-arm action

03The cycle stops because the heat pump is blocked

Likely causes

Start with the least invasive explanation and stop if the check requires internal electrical or sealed-system access.

01Heat pump is blocked

Safe next steps

1
Press ON/OFF to stop the dishwasher; do not remove fixed panels
Follow the exact model manual where access or reset steps differ by product series.
2
At the household breaker, switch dishwasher power off for 30 seconds
Follow the exact model manual where access or reset steps differ by product series.
3
Restore power and start one short rinse cycle
Follow the exact model manual where access or reset steps differ by product series.
4
If E21 returns, stop the cycle: the heat pump needs Bosch-authorized diagnosis and is not a safe DIY repair
Follow the exact model manual where access or reset steps differ by product series.

When to stop

Stop if you see damaged wiring, smell burning, find an active leak, suspect gas or refrigerant, or need to remove a sealed electrical cover. Use a qualified appliance technician.