Bosch dishwasher won't turn off

Sometimes users, having started the dishwasher, notice that it has been running for much longer than the time set by the program and does not want to stop. Moreover, this problem can only be solved by unplugging the power cord from the outlet. What to do if your Bosch dishwasher won't turn off? What parts breakage leads to this? Let's look into the nuances.

Possible causes of the problem

If you notice that the dishwasher does not turn off, do not rush to call a professional. Often the cause of the problem is a software glitch. It occurs due to a sudden voltage drop in the network or a sudden power outage in the house. In this case, rebooting the PMM will help.

To restart your dishwasher:

disconnect the PMM from the network;
wait 15-20 minutes;
turn on the machine and start the cycle.

If restarting does not help, then there is some kind of malfunction. Let's look at typical problems with this “behavior” of a dishwasher.

Pump failure. Probably the pump does not receive a command from the control module and does not start draining water into the sewer. Therefore, the dishwasher continues to work.
Problems with the control module or wiring. Perhaps the triac that coordinates the operation of the drain pump has failed. The reason may also be a damaged cable, due to which the nodes do not receive commands from the unit.
Pressostat malfunction. The level sensor may transmit incorrect information to the “brain” regarding the amount of water in the working chamber. Therefore, the module does not give a command to drain the waste liquid.
Errors when installing PMM. Some Bosch models are sensitive to body tilts.If they are not level, they may not work correctly.
Incorrect connection of the drain pipe. Probably due to errors when installing the PMM, a “siphon effect” is observed. The waste liquid, before it gets into the sewer, is thrown back into the dishwasher chamber. Therefore, the pump does not stop pumping out water.
Blockage in the drain system. The pump will try to remove water into the sewer despite the debris plugs. Because of this, the execution time of the program can increase significantly.
The Aquastop system is activated. If a leak is detected, the dishwasher may react by displaying error E15. Sometimes the machine will simply automatically start the pump, which will begin pumping out water.

Do not discount problems related to the dashboard. In such a situation, the washing also does not stop, and the buttons on the “tidy” do not respond to the user’s touch. What to do in this case? You will have to check whether the contacts have oxidized and whether the triacs on the controller are working properly.

Incorrect connection to communications or blockage

It is very important to follow the manufacturer's recommendations for installing PMM. Some Bosch models are susceptible to housing distortions. Therefore, the device must be placed on a flat and hard floor. If necessary, adjust the position of the dishwasher by twisting its legs.

Then check whether the PMM is connected to the sewer correctly. The drain hose must be located at a distance of 50 cm from the floor level, otherwise waste water may return to the dishwasher hopper. In this situation: check the hose for blockages

disconnect the drain hose from the dishwasher body;
check the corrugation for blockages;
reconnect the drainage hose, positioning it at the required height and bend.

The length of the PMM drain hose should not exceed two meters, otherwise the pump will work under increased load.

The reason for this behavior of the dishwasher may be internal blockage. Cleaning is easy to do with your own hands. For this:

turn off the power to the dishwasher;
open the machine door;
pull out the baskets;
find the drain filter (it is located at the bottom of the washing chamber);
clean the filter assembly from debris and dirt;
there is a hole behind the filter - remove the water accumulated in it using a sponge;
remove the protective cover;
clean the impeller of debris (sometimes a foreign object that gets inside blocks its operation);
Replace the filter assembly.

If after this the machine still cannot complete the program, you will have to check the pump. To diagnose the drain pump:

turn off the power to the dishwasher;
close the shut-off valve;
disconnect the inlet and drain hoses from the machine;
lay the dishwasher on its side;
remove the bottom of the housing by unscrewing the bolts;
Unclench the clamps of the drain pipe, unhook it from the pump;
remove the bolts securing the pump;
pull the pump out of the PMM housing.

Inspect the pump for defects. Disassemble the body of the part, clean the “insides” of debris. A faulty pump cannot be repaired and will need to be replaced.

The pressure switch is clogged with dirt

Most often, the reason why the level sensor transmits unreliable readings is a clog in its pipe. The pressure switch is a round part; inside it there is a membrane and contacts. The fitting goes from the relay to the tank.

The pressure switch reacts to pressure changes in the washing chamber, measuring the volume of water in the hopper.

When the sensor tube becomes clogged, measurement errors occur. The fitting is easy to clean with your own hands.It is simply blown or washed under running water. The pressure switch is located in a plastic box near the circulation pump.

Control board repair

Typical symptoms of this problem are slightly different from those discussed above. In this case, the dishwasher starts and freezes. After this, the buttons on the dashboard do not respond to pressing, and it is impossible to turn off the machine without unplugging the cord from the network.

Each button that the user presses puts pressure on a certain area of the module. If the machine does not respond to commands, it means either the tracks are damaged or the triacs on the control board are oxidized, or the keys are stuck. In this case, repair of the PMM will be required.

The PMM control module is a rather expensive part. You should not try to repair the dishwasher controller yourself without having experience working with electronics. In this case, it is recommended to seek help from specialists so as not to further damage the machine. Bosch dishwasher control board

In general, the algorithm of actions in case of repair of the PMM control module will be as follows:

turn off the power to the dishwasher;
open the PMM door wide;
unscrew the bolts at the ends of the door;
remove the inner part of the PMM door;
disconnect the wires from the controller, remove the fasteners securing the board;
take out the module, test its triacs with a multimeter;
Having identified a breakdown, unsolder the damaged semiconductor and install a new one.

To diagnose the control module you will need a multimeter, for repairs you will need a soldering iron and new spare parts. Having replaced the damaged semiconductors, put the unit in place, assemble the PMM case and run the test cycle.

We eliminate leaks without disassembling the PMM

If the display of a frozen Bosch dishwasher shows error E15, it means there is a leak.The PMM float floats up when water enters the pan of the machine and gives a signal to the module. Often the reason for this is a damaged oil seal.

You can install a new rubber band yourself by purchasing a special repair kit 12005744 produced by the manufacturer Bosch.

In such a situation, it is not necessary to lay the machine on its side and disassemble the body. The job can be completed without even moving the dishwasher. The algorithm of actions will be as follows:

purchase a repair kit from Bosch (it includes bolts, a new rubber band, a special wire for pulling and installation instructions);
turn off the power to the dishwasher;
remove the dish baskets from the washing chamber;
remove the filter element located at the bottom of the hopper;
unscrew the 4 bolts located at the bottom of the washing chamber;
lift and move the water supply to the side;
take the wire from the repair kit intended for installing the elastic band;
slide the wire along with the elastic band under the first fastener (how to do this is described in the instructions included in the repair kit);
lubricate the protruding end of the elastic with a drop of liquid detergent (to make it easier to slide into place);
pull the elastic band into the second fastening;
spread the rubber gasket in a circle;
Reinstall the water supply and secure the pan that was removed at the beginning of the work with bolts.

It is important to not pull the elastic too hard, otherwise it may break. The entire algorithm of actions is described in detail in the instructions included in the repair kit. This repair method is very convenient, since you do not have to disassemble the PMM housing.