Water does not flow into Bosch dishwasher

What to do if there is no water coming into the dishwasher? Call a technician right away or try to solve the problem yourself? In fact, you can deal with most breakdowns yourself. Let's figure out why this situation usually occurs.

What could have gone wrong?

Why isn't water flowing into the machine? There may be several reasons - from a clogged filter to damage to the control module. To identify the problem area, you will have to check each element of the PMM one by one, which may be the “culprit” of the problem.

So why doesn’t water fill into the Bosch PMM? The issue may be:

• clogged flow filter;
• broken intake valve;
• damaged door lock;
• a failed pressure switch;
• activated Aquastop;
• damaged electronic control unit.

Banal user errors cannot be ignored either. So, water will not enter the system if the shut-off valve on the pipe is closed. Be sure to check the inlet hose; it may be kinked or squashed. Make sure the water supply to the house has not been turned off.

It is recommended to start diagnosing a Bosch dishwasher from simple to more complex, “weeding out” one possible problem after another. First make sure it's not a user error. Next, check the flow filter and leakage protection system. We'll tell you how to do this.

Either a filter or leak protection

Often the Bosch dishwasher cannot fill after the Aquastop system is activated. Sometimes users don’t even notice a leak, since a large puddle does not always form under the machine. Therefore, first of all, inspect the PMM inlet hose.

Most modern Bosch PMMs are equipped with leak-proof inlet hoses.

Aquastop inlet hoses are equipped with special valves. If a leak forms in the system, the pipe becomes clogged and the indicator on it turns red. Water stops flowing into the dishwasher.

A “triggered” inlet hose cannot be repaired. They are disposable, so you will have to replace the element. A new part is purchased for a specific Bosch PMM model.

Not all Bosch dishwashers have inlet hoses with the Aquastop protection system. If your PMM is equipped with a regular pipe, then simply inspect it for defects and leaks. If the corrugation is dry, you can proceed to check the next likely “culprit” - the flow filter.

When connecting the PMM to communications, experienced craftsmen install a flow filter on the filling pipe. It acts as additional protection. Its task is to prevent water debris from entering the machine. This filter element must be maintained and cleaned.

There is also a main filter in front of the fill valve of a Bosch dishwasher. With an additional mesh, it clogs less often, but its clogging also cannot be ruled out. To check the filter elements, you must:

• turn off the power to the machine;
• turn off the water;
• unhook the inlet hose along with the filters;
• remove the filter elements, clean out the dirt and rinse them in warm water;
• install all parts in place;
• check the operation of the PMM.

The additional and main Bosch PMM filters must be cleaned at least once every 6 months.

If after this there is no water supplied to the machine, you will have to look for the problem further. Next in line to check is the intake valve. It is located at the connection point of the inlet hose to the PMM body.You will also need to inspect the door locking device and pressure switch.

Inlet valve not working

Often water does not enter the dishwasher due to a failure of the inlet valve. This element is very sensitive to pressure changes in the water supply. If the pressure is slightly higher than normal, the part may break.

Therefore, manufacturers of PMM Bosch, in the instructions for the equipment, urge users to be sure to provide pressure relief valves in cases where the pressure in the water pipe can theoretically exceed 1 MPa. They will prevent water hammer. Many people do not follow these recommendations, which leads to breakdowns.

To check the PMM fill valve, you will need a multimeter. The tester must be switched to resistance measurement mode. Next, the probes of the device are applied to the contacts of the part being diagnosed. Normally, readings should be between 500 and 1500 ohms.

If the values ​​​​on the multimeter screen differ greatly from the standard values, then the water inlet valve is damaged. The part cannot be repaired; it will have to be replaced. Sometimes an element is simply clogged with debris, and to resume the operation of the PMM, it is enough to clean it.

If the fill valve is fine, check to see if the dishwasher door locks after closing. A characteristic click will notify you that the mechanism is triggered. If the lock is broken, the system will remain leaky, which means water will not flow into the working chamber. Repair or replace the blocker.

The next thing to check is the pressure switch. An incorrectly functioning level sensor can transmit false information to the control module about there being enough water in the hopper, while there is none there. Then the “intelligence” will not give the command to dial. The part will need to be replaced.

Control board

The problem may also be in the electronics of the Bosch PMM. Not everyone will be able to diagnose the control module, since the upcoming work requires certain knowledge and skills. Not even every master undertakes such repairs. At home, you can first just look at the block - sometimes the problem can be seen with the naked eye.

What is an electronic unit? The control module controls the operation of all elements of the dishwasher Bosch. It gives the command to draw and heat water, drain waste liquid, switch to rinsing, etc.

Usually it is not the entire module that breaks, but one of its elements. On the board, each semiconductor is responsible for the operation of a specific PMM unit. If you find the damaged part and replace it, the unit will begin to function as before.

First you need to remove the control board from the machine. For this:

• turn off the power to the Bosch dishwasher;
• turn off the water supply;
• unhook the drain and inlet hoses from the PMM body;
• Open the machine door completely;
• Unscrew the bolts located on the side and back of the PMM door;
• remove the top of the door.

Having removed the top part of the dishwasher door, you can see the control module on special latches. Carefully inspect the board for defects, burns, swelling, and rust. If at first glance everything is fine, then there is no need to go deeper; it is better to call a service center specialist.

The technician will check the control unit elements using special instruments. Having identified a malfunction, he dismantles the damaged semiconductor and installs a new one. In rare cases, it may be necessary to completely replace the electronic module of a Bosch dishwasher.

If you see that the dishwasher is not filling, do not rush to call a professional.Often you can solve the problem yourself. One by one, check all the elements of the PMM responsible for collecting water. Having identified a malfunction, replace the part. The dishwasher will function again.

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