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Valves for Bosch Dishwasher

valve for PMMSuch small and simple details as valves for the Bosch dishwasher are of great importance for the operation of the device as a whole. If at least one of the valves of the “home assistant” starts to work intermittently, the machine will either not be able to perform its main function at all, or it will do it with serious interruptions. In this publication, we list all types of valves that are installed in Bosch dishwashers, give them a brief description and talk about the features of their replacement. We hope it will be interesting.

Types of valves

The task of any valve in a Bosch dishwasher is to pass a certain amount of liquid in a certain direction, and then at the right time to block its flow. Solenoid valves operate under the direction of a control module. The latter gives a command, after which the valve either opens or closes. Mechanical valves work independently, but they are no less useful. What types of valves are there in the Bosch dishwasher?

  1. Solenoid inlet valve for water supply.
  2. Check valve drain.
  3. A special valve that protects the machine from emergency leaks Aquastop.

Each of these valves has its own device, is installed in a certain place and changes in accordance with a certain algorithm. We will discuss this in detail below.


The inlet valve has a very important role. It closes the water, which, under pressure, enters the dishwasher. Its main task is to open for a while at the command of the control module in order to pump some water into the machine, and then close again at the command. The valve is activated whenever pure water is added to the dishwasher. Depending on the program, this may be required 2 to 8 times per wash cycle.

filler valve

Violations in the operation of the control module or the wiring connecting the control board to the inlet valve will lead to dysfunction of the latter.

The interconnection of the inlet valve and the control module makes it possible to quickly shut off water, not only in a normal working environment, but also in an emergency. Although in case of an accident the machine has a special valve.


The non-return or anti-siphon valve is much simpler, but this does not mean that its role is anyway diminished. An anti-siphon valve is installed to drain the dishwasher at the base of the drain hose. As soon as the pump begins to pump the waste water into the sewer under pressure, this valve opens and freely passes sewage into the drain. If the pump stops working, the valve closes securely.

drain valve

If suddenly sewage gushes out of the sewer back into the dishwasher, they will be blocked by a reliable anti-siphon valve. Under whatever pressure sewage comes from the sewer, the valve will stop them. Some users who set their own dishwashers themselves ignored this valve and already bitterly regretted it. If there is a blockage in the sewer, all sewage penetrated into the dishwasher and fell into clean dishes. Existing unsanitary conditions! In general, without an anti-siphon valve, no Bosch dishwasher can be imagined, and now you understand why.


The emergency valve is an integral part of the Aquastop system. Some townsfolk mistakenly believe that this valve is the only part of the protective system, but this is not so. Partial leakage protection Bosch dishwashers have a special float sensor in the pan. When enough water enters the sump, the float rises and closes the sensor contact, which in turn sends a signal to the valve. And that instantly overlaps.

aquastop PMM

In the future, in order for the valve to open again, it will be necessary to open the sensor contacts in the drain pan and eliminate the cause of the leak. The Aquastop valve mounted on the inlet hose of the Bosch machine with full leakage protection is triggered when the hose breaks. The fact is that Aquastop hoses on these machines are also unusual. They have a double layer.

  1. When the base layer bursts under pressure, water enters between the layers and presses on the valve.
  2. The valve closes tightly, blocking the flow of water into the machine.
  3. No matter how much the user tries to restart the machine, it will not work.

In this case, no measures will help, you need a complete replacement of the hose, since this system is designed as a disposable one. The next hose will serve until a similar emergency occurs, as this happens infrequently, otherwise the user would go broke buying new hoses.

Features for replacing these parts

When replacing the filler valve, the main thing is not to mix up the contacts when connecting it, but first you have to remove the dishwasher tray. Read more about disassembling the machine in the article How to fix Bosch Dishwasher Error E14, now we will not stop there.

The inlet valve is directly connected to the inlet hose, so it will not be difficult to find it. Before dismantling the old valve and removing wires from it, take a picture of it. Next, check with a multimeter whether the part is working, and then proceed with the replacement. Install the wires in the correct order, and then assemble the machine.

The anti-siphon valve needs to be replaced only if it is clogged. Usually this happens after 5-7 years of operation of the dishwasher. The old valve must be unscrewed, and the new one screwed, nothing tricky. But you need to do this at least 1 time in 7 years, otherwise a clogged valve at a critical moment may not work and you will not like the result.

Aquastop valve is changing easier than others. To do this, it is not even necessary to disassemble the dishwasher, since this valve is located outside. Not only pleasing is its value. On average, it costs about $ 45 and for the duration of a dishwasher (7-12 years), it can fail 2-3 times. Agree, it’s quite expensive, but without it there is a risk of flooding the neighbors from below.

In conclusion, we note that there are not many valves in the Bosch dishwasher, but each of them in its place plays an important role in the overall operability of the equipment. Largely thanks to these details, without physical effort, we wash a mountain of dirty dishes every day. And it costs a lot!


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