How to fix error E21 in a Bosch dishwasher

Modern dishwashers have fairly well-tuned self-diagnosis systems, the database of which contains not unified, but highly specialized codes that allow more or less accurate identification of a particular breakdown. In this case, you can often talk about damage even before the dishwasher is parsed. A prime example: error E21 in a Bosch dishwasher. Seeing this error, we can confidently say that there were problems with the pump, although the nature of the breakdown can be different. Let's discuss it.

Why does the code appear?

Code E21, barely appearing on the Bosch dishwasher display, immediately paralyzes its operation. The washing program stops and the user is forced to put up with unwashed dishes and uncleaned dirty water. Why does this code even appear?

1. A serious blockage formed in the pump area. A blockage paralyzes the operation of this part, making draining water impossible or at least difficult.
2. The impeller of the pump is damaged or badly worn. Also, the E21 code can “pop out” if large debris is clogged in the impeller.

Often difficulty in rotating the impeller appears when hair or threads are wound around it.

3. There were problems with the rotor from which the latter stops rotating or substantially loses speed. This usually happens when the part is brought to an extreme degree of wear.

It is important to remember that the error E21 appears in those cases when the control module recognizes the pump and can control it, but thanks to a special algorithm, it understands that this part works unsatisfactorily. It happens that first appears error E23 in the Bosch dishwasher, then this error begins to alternate with the E21 code (after reboot). This behavior of the dishwasher once again confirms the formation of a blockage close to the pump, but we will talk about this in the next paragraph.

Pump blockage

So, we figured out the reasons for the appearance of the E21 code, now the brain requires details. Let's start with blockages located next to the pump or inside the part. Unfortunately, it is impossible to get to the pump blockage without disassembling the machine, but you can try to clean the dust filter and then restart the dishwasher. It is very possible that water, passing again through a clean filter, will break through a deeper blockage. If this does not happen, we will disassemble the dishwasher to get to its internal parts.

How to disassemble the machine when reaching the parts located in the pallet, including the pump, is described in the article How to fix Bosch Dishwasher Error E14will not be repeated. To remove the pump, which is located on the housing of the circulation module, it is necessary to grasp its body with one hand and turn this part counterclockwise. After that, it can be easily removed. You will also need to disconnect the plug with wires from the pump casing.

Next, take a cloth, wrap it on your finger and begin to remove the dirt from the niche in which the pump was. After such cleaning, sometimes a good handful of densely crumpled food debris is accumulated, which, among other things, also smell bad. Having cleaned the seat and checking how the impeller rotates on the pump, you can return the part to its place and assemble the dishwasher in the reverse order.

Impeller problems

Removing the pump may indicate that the impeller is worn out and cannot fulfill its direct function. This is one of the most noticeable failures, since a broken impeller can be recognized from afar, because it will be a pity to look at its blades. The impeller on the pumps of the Bosch dishwashers is removable, it is quite possible to change it, although it is very difficult to find this item on sale.

You can try to buy this part somewhere at the parsing, but we repeat again, the chances are small.Some people suggest restoring the old impeller by soldering missing or broken vanes to it, but we are committed to quality repairs, so we suggest you buy and install a new drain pump.

A new pump will cost at least $ 33, but at least you will save on work.

It happens that the blades on the impeller of the pump were not affected at all, but on the other hand a whole coil of some threads hung on them, hair mixed with pressed food leftovers. Under such conditions, the impeller cannot work normally, it must be cleaned. As soon as the cleaning is completed, feel free to collect the dishwasher and put it back into work.

Rotor jamming

When assembling modern Bosch dishwashers (especially cheap models), spare parts of rather poor quality are used. This makes itself felt, because the average life of new machines is much shorter than that of the same units produced 7-10 years ago. Speaking specifically about pumps, the craftsmen note a lack of lubrication in their rotors. It seems that the manufacturer intentionally saved grease so that the part would fail earlier and the dishwasher owners would rather buy spare parts for it.

After some time, a poorly lubricated rotor starts to wedge and rotate poorly, and this in turn causes the E21 error. How to fix this breakdown?

• We purchase special rotary grease for electric pumps.
• We remove the impeller from our pump.
• Lubricate the rotor according to the instructions that are on the tube with grease.
• We put the impeller in place and check its rotation.

That's all. Now you can put the "resuscitated" pump in place and collect the dishwasher in order to check it in operation. Most likely, after repair, your dishwasher will last a long time. Good luck