Error E20 on a Bosch dishwasher

The more you use your dishwasher, the greater the chance of encountering a fault code you've never encountered before. Error E20 is one of these, as it's rarely encountered by new users, often leaving homemakers stumped. It alerts the user to problems with the circulation pump, its components, or the winding, which are usually difficult to resolve without calling a service technician and subsequent expensive repairs. However, you can fix the problem yourself if you carefully follow our guide.

Why did the circulation pump break down?

The circulation pump in a Bosch dishwasher rarely fails, so if the E20 error code appears, don't immediately disassemble your dishwasher and inspect the pump for damage. First, it's worth examining the drainage system, which could simply be clogged with debris or broken dishware that has blocked the pump impeller.

If we consider the worst-case scenario—damage to the pump—the cause could be sudden power surges that caused a winding break. Liquid could also have spilled onto the pump's electronic components, or the heating element could have burned out. All of these steps need to be checked to reset the E20 error.

First reboot and clean

This error code in a Bosch dishwasher could be caused not only by clogged or broken dishes, but also by a one-time system failure. Therefore, the first step is to reset the machine by unplugging it for about 15 minutes. If this doesn't resolve the E20 error, as it reappears on the display, you'll need to proceed to the next steps.

Let's start by cleaning the waste filter located at the bottom of the dishwasher's wash chamber. To access it, open the bin door, remove all the dish racks, and unscrew the filter. Next, rinse it thoroughly under a strong stream of hot water, or use a sponge or brush.

If the stains are stubborn, you can soak the part in a citric acid solution for several hours.

After the filter, locate the drain pump. Be sure to remove all water from the hole, which is easiest to do with a large sponge. Then, remove the fasteners and take out the drain pump cover. This will give you access to the impeller, which you should inspect for damage, debris, and broken glass. If the impeller is fine, but the E20 error persists, you'll need to inspect the pump itself.

Removing the circulation pump

If the error code is caused by the circulation pump, the only way to fix it is by disassembling the appliance. This should only be done if the warranty has expired, otherwise, your actions will void the warranty. What should I do to access the pump?

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

Just in case, take a few photos of the correct wire connections to the electronic component - you will need them when reassembling the dishwasher.

• Finally, remove the pump itself.

As you can see, the disassembly process takes a lot of time and effort, so if you're unsure, it's best to call a service center specialist who can quickly disassemble the machine and test the pump.

Checking and replacing the circulation pump

The E20 error in Bosch dishwashers most often occurs due to worn graphite bushings in the circulation pump. These components can only be checked after disassembling the machine and gaining free access to the pump. If, during the inspection of the bushings, you notice significant play, then they must be replaced to correct the problem. What to do for this?

• Disassemble the pump, 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 an impeller from a hardware store or online retailer that sells 3D-printed dishwasher parts.
• Install new elements in place of damaged ones.
• Assemble the pump and the Bosch dishwasher according to our instructions in reverse order.

If you order spare parts online, be sure to specify the exact model of your "home helper" to ensure the part is compatible with your appliance.

You can also check the pump coil with a standard multimeter, as this component can also sometimes fail, requiring replacement of the entire circulation pump. After replacing the unit or its parts, be sure to test the Bosch dishwasher's functionality by running an empty cycle without any dishes. Only after the E20 error has been resolved should you reinstall the appliance in the kitchen cabinetry.

   

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