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Bosch Dishwasher E21 Error Code
Heat pump blocked. Here is what it means and how to clear it, easiest fix first.
The heat pump, which moves wash water around the dishwasher, isn't turning freely. Debris or a mechanical fault in the pump can cause this.
Newer US models show E6002. European guides list E21 as a fault that needs service.
How to fix Bosch E21
Clean the filter
Switch off the breaker or unplug the unit, then remove and rinse the filter. A badly clogged filter can let debris reach the pump.
Reset the dishwasher at the breaker
Switch off the dishwasher's circuit breaker, wait about 30 seconds, then switch it back on. Run a short cycle with the dishwasher empty and watch whether the same code comes back. A code that clears and stays away was likely a one-time glitch.
When to call a technician
If E21 returns after a reset, call Bosch support or a technician. The pump needs to be inspected and possibly replaced.
Parts that commonly cause E21
- Heat pump (circulation pump with heater)
Order parts by your exact model number so they fit.
Other Bosch dishwasher codes
- E15Water detected in the base (leak protection)
- E24Dishwasher is not draining (blocked drain path)
- E25Drain pump blocked or pump cover loose
- E22Filter is blocked
- E23Drain pump fault
- E16 / E17Water can't enter the dishwasher
- E18Water level too low
- E14Flow meter or filling problem
- E09Heating fault (meaning varies by region)
- E27Household power supply too low
- E12Limescale buildup in the heat pump
- E01-E05Control board or electronics fault
- E06Door sensor circuit fault
- E19Detergent dispenser fault
- E07 / E10CrystalDry (zeolite) drying fault
- H01Delay start is set (not an error)
Frequently asked questions
What does E21 mean on a Bosch dishwasher?
The heat pump, which moves wash water around the dishwasher, isn't turning freely. Debris or a mechanical fault in the pump can cause this.
Can I fix Bosch E21 myself?
Only the basic checks. You can safely try the steps above, but E21 usually points to a part or fault that needs a technician.
What if E21 keeps coming back?
A code that returns after a reset and the checks above usually means a part is wearing out. Note when E21 appears (which cycle, how often) and have your model number ready; it helps a technician bring the right part on the first visit.
Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.