Bosch dishwasher error code e21When a Bosch dishwasher displays error E21, it means it has problems with the drain pump. Let us find out how to detect and fix the problem with your own hands.

Causes of malfunction

Why Bosch dishwasher can display icons E 21:

  1. The impeller is blocked. This happens when the appliance is treated carelessly. Late cleaning of the drain leads to clogging of the filter and the impeller with food leftovers, small particles and bones.
  2. Pump failure. Such an outcome is possible with a long service or a burnout of contacts and wiring.
  3. Problems with the rotor. If it gets stuck due to a lack of lubrication, then the impeller will not rotate.

How to restore the work of the dishwasher? Let’s consider possible solutions.


If the error is on again, then you should carry out an inspection:

  1. Disconnect the machine from all communications and unplug it from the power grid.
  2. Open the door and remove the rack.
  3. Unscrew the drain filter from the sump.
  4. The pump is located behind the filter.
  5. Loosen the screws and remove the cover by pulling it towards yourself.
  6. Check the impeller for debris that could block it.

Now you need to check the drain pump. Turn the machine upside down, remove the bottom cover by unscrewing the screws or moving the clamps. The pump is located next to the circulation unit. Unscrew the mounting bolt and disconnect the wiring leading to it. Take the pump and turn it counter-clockwise.

The pump can be inspected visually, while the diagnostics of the electronic part will require the use of a multimeter.