How to Fix Bosch Dishwasher Error E21

Error Code: E21 Difficulty: Hard

Problem: Blocked heat pump.

How to Fix E21 Error (Step-by-Step)

1. Cut all power to the dishwasher by switching off the corresponding circuit breaker.
2. Turn off the hot water supply valve under the sink.
3. 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.
4. Identify the circulation pump, which is a large motor and housing assembly near the center.
5. 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.
6. Remove the screws or release the tabs that mount the pump to the dishwasher’s sump assembly and remove the old pump.
7. Mount the new circulation pump, reattach the hoses and wiring, and carefully return the dishwasher to its upright position before reinstalling and testing.
8. Turn the appliance off, wait about 2 minutes, then turn it back on.

Still Not Working?
If the replacement part didn’t fix the issue, you may have a wiring problem or main board failure.