Error code guideE21

Bosch dishwasher E21 error: the circulation pump is blocked

Bosch dishwasher E21 means the heat pump is blocked on supported models. This is distinct from E20, which Bosch defines as an internal heat-pump heater fault.

Model check required. Confirm E21 against the exact Bosch E-number documentation because components and service procedures vary by dishwasher platform. Do not assume a filter blockage when the model reports a heat-pump blockage.

Reviewed Sep 3, 20264 minute guideDishwasherSelected Bosch dishwasher model families

Quick answer

Bosch dishwasher E21 means the heat pump is blocked on supported models. This is distinct from E20, which Bosch defines as an internal heat-pump heater fault.

Start here: Reset power for 30 seconds. Follow Bosch's first step: switch power off at the breaker for about 30 seconds, restore it, and retry once.

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Guided check

Match the symptom, then work through the safe checks.

0/3 checked

1. What best matches what you observe?

2. Complete only the checks that are safe for you.

Reset power for 30 secondsFollow Bosch's first step: switch power off at the breaker for about 30 seconds, restore it, and retry once.SafeDo not confuse E21 with a filter-only codeBosch specifically describes E21 as a blocked heat pump. E22 is the code Bosch associates with a blocked dishwasher filter.SafeAvoid reaching into internal pump componentsThe heat pump is an internal assembly. Do not remove panels or attempt energized mechanical/electrical testing unless qualified.Caution

Arrange service if E21 returnsPersistent E21 requires model-specific diagnosis of the heat pump, obstruction, motor movement, wiring, or control feedback.Professional

3 user-level checks are available in this guide.Stop immediately if any warning condition applies.

Show stop conditions

Burning electrical smell
Motor or wiring becomes hot
Breaker trips or movement is seized

Likely causes

The heat pump is mechanically blocked
Debris or an internal obstruction is preventing normal pump movement
The heat-pump motor cannot rotate as expected
The control continues to detect a blocked heat pump after a reset

Quick checks, in order

Reset power for 30 seconds

Follow Bosch's first step: switch power off at the breaker for about 30 seconds, restore it, and retry once.

safe

Do not confuse E21 with a filter-only code

Bosch specifically describes E21 as a blocked heat pump. E22 is the code Bosch associates with a blocked dishwasher filter.

safe

Avoid reaching into internal pump components

The heat pump is an internal assembly. Do not remove panels or attempt energized mechanical/electrical testing unless qualified.

caution

Arrange service if E21 returns

Persistent E21 requires model-specific diagnosis of the heat pump, obstruction, motor movement, wiring, or control feedback.

Professional

Does the blocked-heat-pump code return after the Bosch reset?

E21 clears after the reset

Run one normal cycle and monitor. A recurring E21 still indicates an intermittent blockage or heat-pump movement problem.

E21 returns as soon as circulation should begin

The heat pump may still be unable to rotate or circulate normally. Stop repeated attempts and arrange service.

You hear unusual grinding or repeated starting attempts

Stop the cycle. Mechanical resistance around the heat-pump assembly needs professional inspection.

Stop and get qualified help when

Do not continue troubleshooting if any of these apply:

Burning electrical smell
Motor or wiring becomes hot
Breaker trips or movement is seized

Official support and model manuals

Use the full model number from the rating label. The manufacturer manual is the deciding reference when codes differ by region or product family.

Bosch Support — dishwasher error codes

Frequently asked questions

What does Bosch dishwasher E21 mean?

Bosch identifies E21 as a blocked heat pump on supported dishwasher models.

Should I clean the filter for Bosch E21?

A clean filter is good maintenance, but Bosch's code list specifically assigns blocked-filter guidance to E22. E21 points to the heat pump itself and should be serviced if the reset does not clear it.

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The E06 display on many Bosch dishwashers indicates that the door sensor is not reporting correctly. Codes can vary by model, so match the full model number to the official manual before ordering parts.

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