Error E20 on a Bosch dishwasher

Error E20 on a Bosch dishwasher The more actively you use the dishwasher, the greater the chance of encountering a fault code that has never occurred before. Error E20 is just one of these, because it rarely occurs to beginners, so it usually causes stupor in a housewife. It informs the user about problems with the circulation pump, its parts or windings, which are usually not easy to deal with without calling a service center specialist and subsequent expensive repairs. However, you can deal with the problem yourself if you strictly follow our guide.

Why did the circulation pump break down?

The circulation pump in a Bosch dishwasher rarely fails, so if error code E20 appears, you should not immediately disassemble the “home assistant” and examine the pump for damage. First, it is worth examining the drainage system, which could simply be clogged with debris or fragments of broken dishes blocking the pump impeller.

If we consider the worst case scenario, namely damage to the pump, then the reason for its failure may be hidden in sudden voltage drops in the network, which provoked a break in the winding. Also, liquid could get on the electronic elements of the pump, or the heating element could burn out. All this needs to be checked in order to reset error E20.

First reboot and clean

The indicated error code in a Bosch dishwasher could appear not only due to clogs and broken dishes, but also due to a one-time system failure. That's why the first thing you should do is reboot the machine by unplugging it from the power supply for about 15 minutes.If it was not possible to eliminate error E20 in this way, since it was again displayed on the display, then you will have to proceed to the following steps. cleaning the dishwasher filter

Let's start by cleaning the debris filter installed at the bottom of the PMM washing chamber. To get to it, you need to open the bin door, remove all the dish baskets and unscrew the filter. Then it should be thoroughly rinsed under powerful pressure of hot water, or with a sponge or brush.

If contamination persists, you can soak the part in a citric acid solution for several hours.

Following the filter, you need to find a drain pump. Be sure to remove all the water from the hole, which is best done with a large sponge. Then remove the fasteners and remove the drain pump cover. This will give you access to the impeller, which needs to be checked for damage, debris and broken glass. If everything is in order with the impeller, but error E20 does not disappear, then you will have to start checking the pump itself.

Removing the circulation pump

The error code can be eliminated if the cause is hidden in the circulation pump only by analyzing the “home assistant”. This should only be done if the warranty period has already expired, otherwise your actions will void the warranty. What should I do to get to the pump?

Disconnect your Bosch dishwasher from all communications.
Remove the equipment from the niche of the kitchen unit by removing the mounting bolts if it is a built-in model, or simply move the equipment away from the wall if you have a freestanding machine.
Open the washing chamber door.
Remove all dirty dish baskets.
Unscrew the legs with a wrench so that they do not interfere with work and the machine can be removed from the furniture.
Unscrew the fasteners and remove the decorative facade along with the cover on the dishwasher door opening mechanism.
Pull the tensioner ropes installed to open the door towards you to temporarily move them aside.
Remove the panel with ropes on the other side of the Bosch PMM.
Turn the machine upside down.
Remove the two screws that hold the bottom decorative panel of the "home assistant" installed on the front of the case, and then remove it.
Pry the clamp of the filler pipe to disconnect the hose.
Disconnect the power cord from the device body.
Remove the fasteners for the drain and inlet hoses from the rear side of the housing.
Disconnect the Aquastop leak protection system sensor.
After releasing the latches, lift the lower part of the machine body.
At the bottom of the Bosch dishwasher, disconnect the Aquastop float.
Remove the PMM tray.
Disconnect the pipes and wiring from the pump.

Just in case, take a few photographs of the correct connection of the wires to the electronic element - they will be needed during reassembly of the dishwasher.

Finally, remove the pump itself.

As you can see, the disassembly process takes a lot of time and effort, so if you are not confident in yourself, it is better to call a service center specialist who will quickly disassemble the machine and test the pump.

Checking and replacing the circulation pump

Most often, error E20 in Bosch dishwashers appears due to worn-out graphite bushings on the circulation pump. You can check these elements only after disassembling the machine and gaining free access to the pump. If during checking the bushings you notice serious play, they must be replaced to eliminate the problem. What should I do for this?

Disassemble the pump by first removing the nozzle on the rotor.
Carefully remove the fragile impeller from the shaft, which may also need to be replaced as it can easily be damaged in the process.
Order bushings and impellers from a hardware store or from online stores that sell 3D printed parts for PMM.
Install new elements instead of damaged ones.
Reassemble the pump and Bosch dishwasher according to our instructions in reverse order.

If you order spare parts online, be sure to indicate the exact model of your “home assistant” so that the part fits your household appliance.

Additionally, you can check the pump coil with an ordinary multimeter, because this element also sometimes fails, which is why you have to change the entire circulation pump. After replacing a unit or its parts, be sure to check the functionality of the Bosch dishwasher by running an idle cycle without dishes. Only when error E20 is eliminated should you reinstall the equipment into the kitchen set.