Error Code: E21 Difficulty: Hard
Problem: Blocked heat pump.
How to Fix E21 Error (Step-by-Step)
- Cut all power to the dishwasher by switching off the corresponding circuit breaker.
- Turn off the hot water supply valve under the sink.
- Gently slide the dishwasher out from its installed position. It’s best to place it on its back on a soft blanket or cardboard to access the underside.
- Identify the circulation pump, which is a large motor and housing assembly near the center.
- Disconnect the electrical wires leading to the pump and detach the inlet and outlet hoses. Have a shallow pan and towels ready for water that will drain out.
- Remove the screws or release the tabs that mount the pump to the dishwasher’s sump assembly and remove the old pump.
- Mount the new circulation pump, reattach the hoses and wiring, and carefully return the dishwasher to its upright position before reinstalling and testing.
- Turn the appliance off, wait about 2 minutes, then turn it back on.
What to Check Next on This Bosch Dishwasher
E21: E21 is a wash/circulation path on many Bosch dishwasher fault lists. Look for blocked movement before replacing the pump.
- Remove and clean the filter, then inspect the sump for glass, labels, or debris that could block the impeller area.
- Check that spray arms spin freely and are not clogged, then run a short cycle and listen for strong circulation.
- If circulation is weak after cleaning, inspect the circulation pump, capacitor where used, wiring, and control feed.
If the symptom returns after these checks, use the full Bosch model number from the door tag before ordering any part. The same display message can point to different parts depending on the exact model and what the dishwasher does during fill, wash, drain, or dry.
Recommended Parts to Check
No exact official OEM part number is listed here because the correct Bosch dishwasher part can vary by complete model number. These are targeted part-category searches, not universal fit claims.
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Bosch dishwasher water inlet valveCommon replacement category: Water inlet valveFit note: Exact OEM part number varies by full Bosch dishwasher model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for fill and water-supply faults after the tap, hose, and inlet screen are checked. -
Bosch dishwasher drain pumpCommon replacement category: Drain pumpFit note: Exact OEM part number varies by full Bosch dishwasher model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for drain and standing-water symptoms after the filter, sump, and hose are checked. -
Bosch dishwasher circulation pumpCommon replacement category: Circulation pump / wash motorFit note: Exact OEM part number varies by full Bosch dishwasher model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for wash, spray-arm, and circulation symptoms after filters and spray arms are checked.
Before ordering: match the part to the complete Bosch dishwasher model number on the appliance tag.
Still Not Working?
If the replacement part didn’t fix the issue, you may have a wiring problem or main board failure.
More options (for a better recommendation)
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When It’s Better to Replace Than Repair
Dishwasher repairs can add up quickly when the pump, control, heater, or leak-related parts fail.
Confirm cabinet width, water line, drain routing, electrical connection, and panel style before ordering.
For repair parts, verify exact fit with the full dishwasher model number before buying; these links are general replacement-appliance shopping options.
- [OK]Drain pump or circulation pump failure
- [OK]Leaking tub, door, or float-switch issues
- [OK]Heater or control failures on an older unit
- [OK]Repeated poor washing or drying performance
Recommended Dishwasher Replacement Options
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