The dishwasher won't turn off.

the dishwasher won't turn off Much has been written about malfunctions characterized by a dishwasher not turning on. But there are also reverse symptoms. The dishwasher starts and runs normally, but then, for some reason, it fails to stop. The only way to stop it is by unplugging the power cord. This problem is common in Bosch dishwashers and other models, so we decided to take a closer look at the possible causes and troubleshooting steps.

The pump does not turn off

The dishwasher pump is designed to pump wastewater out of the wash tank. During the wash cycle, wastewater can be removed multiple times. The program algorithm determines when the control unit should turn the pump on and off, as well as the drain pump's operating time.

It is very important at what moment the command to turn on the pump is given. The control unit must collect information from all sensors and, based on this information, decide whether to turn on the pump. If the pump runs continuously and does not turn off, this means:

the electrics or electronic module are faulty – commands are not sent to the pump or they do not reach the pump;
The control module receives information from the pressure switch about excess water in the Bosch dishwasher;
the machine is not installed level (some models of dishwashers are sensitive to slopes and do not work properly even at a 5 degree angle)⁰);
The Bosch dishwasher is not connected to the sewer system correctly, which leads to a "siphon effect" (backflow of dirty water into the machine), and the pump is forced to constantly try to pump out the water;
the pump itself is faulty.

There are also optional reasons for the pump to run constantly, such as a leak in the inlet hose or pipe. But in this situation, it's quite difficult not to understand why the drain pump is behaving strangely, as water will be leaking from underneath the car, and quite heavily.

Aquastop dishwasher hose This can prevent this, but then the pump won't show any signs of failure. Even if your dishwasher doesn't have Aquastop protection at all, a minor hose leak won't affect the pump's operation. For the drain pump to react, a significant pressure drop is required, which can cause either water hammer or a ruptured hose or pipe.

Please note! Aquastop's full protection will protect your dishwasher from leaks of any kind, but you still need to be careful.

The symptom of a malfunction is a constant humming sound emitted by the pump, regardless of whether a wash cycle is running. Furthermore, if the dishwasher is disconnected (by unplugging the power cord), the pump will continue to run continuously when turned back on.

The troubleshooting procedure will depend on the nature of the problem. Let's start with a simple reason: if your Bosch dishwasher isn't connected to the drain properly, what should we do?

Unscrew the drain hose from the siphon or sewer pipe.
We check that the length of the hose does not exceed 2 m.
We check the bend and the connection height of the hose (the height of the connection point from the floor should be no more than 50 cm).
We redo the connection to the sewer and screw the hose back on.

After this, the pump should stop acting up and start working normally. If, after fixing the sewer connection, your Bosch dishwasher continues to use the pump excessively, you can inspect how the machine is installed on the floor. Bosch dishwashers are not overly demanding regarding the installation surface; even steep slopes of 8-10° are acceptable.⁰ . Electrolux brand machines are more capricious, so they need to be installed level on a solid, reliable surface.

If the dishwasher is installed properly, the problem is likely with one of the components, a sensor, or even the control module, which is not a good sign. Brace yourself for the expense and start checking the machine's electrical and electronic components.

By the way, you don't necessarily have to do this yourself. If you encounter serious problems with your dishwasher's electronics, it's best to contact a professional. This reduces the chance of further damaging the dishwasher. But if you're determined to see this through, at least consider the advice of professionals.

The washing program does not start and does not turn off

If the Bosch dishwasher (or another one) does not respond to any user actions after being turned on, that is, most of the buttons do not work and it is impossible to turn on any washing program, In this case, it is also impossible to turn off the machine using the button – this indicates a malfunction of the control panel. More precisely, there's a problem with one of the control triacs or the contacts of one of the buttons. If several buttons don't work at once, then the triac is most likely the problem.

Please note! A triac is a special semiconductor component installed on the control board of Bosch dishwashers (and other brands). It is also known as a symmetrical triode thyristor.

Testing and replacing a triac requires minimal knowledge of semiconductor circuits and the ability to use a soldering iron and a multimeter. First, let's set up the multimeter.

We turn on the device and set it to voltmeter mode.
We set the minimum value in Volts.
We short-circuit the multimeter probes and check how the device works. If everything is normal, we move on to the next step.

Now we need to access the control board. Disconnect the power to the dishwasher and open the door. There are small fasteners on the ends of the door and on the inside; remove them while holding the door open. The inside of the door will pop off like a sandwich, exposing the control board. Next, proceed as follows. triac

We find the triacs on the control board (see photo) and check them one by one using a multimeter.
If you find a faulty part, carefully unsolder it and remove it.
Take the broken part as a sample and buy a similar one in the store or take one from a non-working device.

Important! The numbers and markings on the faulty part and the new one must match.

Very carefully, so as not to damage the tracks, solder the new part in place of the old one.

Now we replace the control board, reassemble the door, connect the power to the dishwasher, and test its operation. After these simple steps, the dishwasher should turn on and off normally.

The washing program is frozen

control board A dishwasher often fails to turn off due to a system error. System errors are programmed into the machine's control module; they help perform self-diagnostics and inform the user about various malfunctions. A system error displayed on the dishwasher's display stops it from operating, and in some cases, even prevents it from being restarted using the on/off button. Turning the machine on again does not solve the problem, the error appears again.

A striking example is Bosch dishwasher error code E22This error occurs when the dishwasher user forgets to clean it. The filter becomes clogged, the sensors are triggered, and the control module blocks the entire machine until the blockage is cleared. In this case, the dishwasher does not turn off and does not respond to any user input.

If your dishwasher won't turn off due to one of the many system errors, there's only one solution: find the cause and fix it. Only then will you forget what it's like to watch your dishwasher not turn off.

To summarize, if a dishwasher won't turn off, it's a worrying symptom that indicates a more serious problem, usually a breakdown. It's bad news if the pump or, worse, the control module is broken, but sometimes a simple clogged filter can interfere with the dishwasher's operation. This is yet another reason to remind dishwasher users of the need to regularly maintain their "iron helpers."