How does a dishwasher inlet valve work

The dishwasher's solenoid valves

The solenoid valves in dishwashers

There are a number of solenoid valves on the dishwasher that are required for the various work processes. Most of them will work for the life of the dishwasher without causing a single problem. Others, in turn, are increasingly responsible for malfunctions. The following is an overview of the most important solenoid valves:

  • Aquastop valve (with an electric Aquastop in the dishwasher)
  • Inlet valve (double valve, with or without pressure cell)
  • Valves for the water pockets (inlet, outlet)
  • Regeneration
  • Rinse aid dosage
  • for the wash levels (upper basket)
  • Circulation valve

The valves most often associated with a defect

In most cases there is a malfunction in one of the valves, all of which are related to the water supply. As a result, the most common malfunction is that the dishwasher does not draw water.

Solenoid valves in the water supply system

Depending on which device you have, the following solenoid valves come into question:

  • Aquastop
  • Inlet valve
  • the two valves on the water pocket (encoder system, level system)

Check the Aquastop using a bucket test

Before you check the Aquastop system, remove the inlet hose from the shut-off valve on the wall side. It is possible that only the sieve is dirty. Screw the hose back on and now loosen it on the dishwasher. You are now performing a bucket test. Turn on the angle valve, hold the other end of the hose in a bucket and measure the amount of water that flows in in one minute.

Water flow after the water pocket

It should be at least 5 liters, usually around 10 liters. By the way, you can also check the feed system in the dishwasher. Pull the drain from the water pocket and check how much water arrives within a minute. Often the water only comes out here as a trickle. But first check the inlet valve.

Defects on the inlet valve with pressure cell

For the inlet valve in particular, there are models with a vacuum unit. If this valve strikes, you should first check whether the valve has accidentally triggered (this can happen). To do this, pull off the hose to the pressurized can, suck in the air and close it again. In principle, this pressurized can has the same function as an air trap. If there is too much water in the device, the pressure rises and the valve closes. We have described the elimination of the problem in detail under “Dishwasher does not draw water”.

Inlet valves as double valves

In the case of an electric double valve, the second valve would completely open and close in the event of a defect. If, for example, the solenoid of one valve has burned out when both valves are currently open, the second valve takes over the opening and closing. In the event that the defect occurred when both valves were closed, it is no longer of any use if the second valve opens - water can still not flow through.

Remember: a valve is not always the cause

Again, depending on which device you have, components such as the dishwasher's water pocket, sensor system, float and float chambers, level system can be checked for soiling.

But even if no water flows out of the water pocket or only too slowly, it could be contamination in one of the components mentioned - or the tappets in the valves.

The circulation valve

The circulation valve is responsible for ensuring that the water runs through the heating circuit, if necessary, until it has the required temperature. Then it is directed into the spray arms. Devices with which only one level is supposed to wash (upper basket) are ball circulation valves. Depending on how this valve fails, it can have the following effects:

  • Water no longer heats (or sporadically)
  • Wash ware is not clean despite the freely moving and clean spray arms

Temporarily repair the circulation valve

In the case of a device where the ball is installed so that the cleaning level can be set to the top, the ball can also be removed from the circulation valve. Then, however, the separate washing on only the upper level no longer works.

Please note that the valves also work with electricity. You must also measure the valves accordingly to determine whether there is a defect. But since mostly 220 V are applied, there is an absolute danger to life for laypeople. This work should therefore only be carried out by experienced specialists, which is why we will not describe it in detail here.

In addition, we have only described possible malfunctions of the most important valves here. Different effects can also have a different cause. For example, a clogged water pocket or, in the case of a circulation valve, a component jammed with a foreign body (also not necessarily the circulation valve).