Error E20 in a Bosch dishwasher indicates an issue with the circulating pump, its parts, or winding.

Causes of malfunction

The circulation unit fails extremely rarely, so before you disassemble and inspect the element, you need to check the drain system. There might be a clogging in the filter, or the impeller of the pump is blocked with sludge. These are also the reasons why the system displays code E 20 on the display.

What could have affected the failure of the circulation pump:

1. Voltage drops could lead to a breakage of the winding.
2. Water got on the electronic parts.
3. The heating element has burnt out.

How to fix the damage yourself

1. Open the door.
2. Remove the rack.
3. Unscrew the drainage filter located in the sump.
4. Wash it with water or clean it with a brush.
5. The drain pump is located behind the filter.
6. Pump the water out of the hole with a sponge.
7. Remove the mounting screws.
8. Pull out and remove the cover.
9. Check the impeller for clogs.

How to understand that the circulating pump is out of order: you will not hear the noise from the unit during the operation of the dishwasher. You will need to take the Bosch dishwasher apart to check or replace the part:

1. Remove all racks from the tub.
2. Disconnect the machine from all communications, unplug it from the outlet.
3. Put the appliance on its back.
4. Unscrew the bolts or unfasten the bottom panel clamps.
5. Carefully inspect the wiring for any damages.
6. Remove the drain pump and the heater, check their performance.