Error E04 on a Bosch dishwasher

Error E04 on a Bosch dishwasher To cope with any dishwasher problem, it is enough to know not the customer service phone number, but the decoding of the fault codes. This will prevent you from getting into trouble, for example, when error E04 is displayed on the display of your home assistant. This code means that the equipment is unable to provide the required level of pressure in the circulation unit. This is a rather critical malfunction, because because of it, water either cannot come out of the sprinkler nozzles, or it comes out, but without sufficient pressure to wash dirty dishes. Let's figure out how to deal with this problem with our own hands.

Preparing for diagnosis

The possibility cannot be ruled out that error E04 in the Bosch dishwasher appeared due to a normal blockage, so this needs to be checked and eliminated first. If it was not possible to reset the error code in this way, you will have to partially disassemble the “home assistant” in order to conduct a high-quality diagnosis.

Do not under any circumstances open the housing of a household appliance if the machine is still under warranty, as this action will void it.

When the warranty period has ended, you can start working. Prepare in advance a Phillips slotted screwdriver, pliers and a regular multimeter to check the functionality of the key components of the PMM. When the preliminary procedures are completed, you can begin to disassemble the equipment. Let's check the FPS with a multimeter

First, be sure to disconnect your Bosch dishwasher from all communications.
Disconnect the inlet hose and drain any fluid remaining from the last operating cycle.
Disconnect the drain hose and inspect it for blockages.
Attach the hose to the back wall of the dishwasher using the fasteners provided by the manufacturer.

Now the machine can be moved to the center of the room to provide free access to all its sides.

Is there a lot of dirt inside?

Often, the spray arms of a Bosch dishwasher stop spinning normally precisely because the drain system of the unit is clogged. First you need to thoroughly clean the drain, and then examine the pump impeller. What should I do to completely clean the element?

Make sure that there is no water in the tank, and if there is any left over from the last wash, it must be removed using the drain hose.
Next you need to remove all the dish baskets from the PMM hopper.
Pull out the debris filter installed at the bottom of the washing chamber.
Find the mesh filter installed directly under the garbage filter and remove it too.
If the contaminants cannot be removed with the filter, since over time they have become embedded in the parts, then you can use a solution of citric acid, in which the elements can be soaked for several hours.
Use a cloth or sponge to remove any water that may have accumulated there from the dust filter seat.
Remove the protective cover by pulling it towards you.

All described actions must be performed with protective gloves so as not to accidentally cut yourself with fragments of broken dishes, which often get stuck in the impeller.

The manipulations performed will allow you to gain access to the pump impeller, which often causes error E04. Examine the part for damage and carefully inspect it to make sure there are no foreign objects inside. Remove glass shards and other debris if present, and replace the impeller if damaged. clean the PMM spray nozzles

If you still can’t reset the error code, you can try to manually clean all the sprinkler nozzles using a toothpick or a needle. This will take quite some time, but it is necessary in order to eliminate the problem with water circulation.

One of the pumps is not working correctly

When error E04 in a Bosch dishwasher remains even after clearing the blockage, it is necessary to test the drain pump and circulation pump. Let's start with the pump.

Carefully remove the sprayer.
Using a screwdriver, remove the bolts installed on the bottom of the washing chamber.
Just in case, cover the floors with rags or unnecessary towels.
Lay the dishwasher on its side.
Disconnect the bottom from the household appliance.
Carefully disconnect the water level sensor wiring that is attached to the bottom panel on the back side.
Remove the motor wiring contacts.

Pay attention to the drainage pump, which is located on the side. You need to remove it and thoroughly clean the seat from dirt. Next you should check the part using a multimeter. If the pump is damaged, then you should not try to restore it, since this element is easier to replace with a new one. Purchase an original spare part that will fit your Bosch dishwasher and install it according to our instructions, performing all steps in reverse order. dishwasher pump

Also, the lack of rotation of the sprinklers may be caused by damage to the circulation pump. The procedure in this case will be similar. If the pump motor makes a loud noise, but the “home assistant” does not turn on and the sprinklers do not rotate, then the problem is clearly in the motor. What should I do to test it and replace it with a new one?

Loosen the pipe clamps.
Disconnect the connectors that power the assembly.
Using a screwdriver, release the latches.
Carefully remove the mounting screw.
Remove the fasteners of the other pipes.
Carefully remove the motor and check it with the same multimeter.
Replace the part if it fails.

If you want to encounter error E04 and other fault codes in your Bosch dishwasher as little as possible, then try to regularly clean the hoses and filters of any contaminants. You can easily handle this yourself without calling a service center specialist, so this procedure should be performed at least once a month.