When it comes to replacing a pump in a Bosch, Ariston, Indesit, Electrolux or other brands dishwasher, the first thing to do is to understand the design of the appliance. It is important to understand which part will have to be changed, because the drain pump and the circulation pump (engine) are two different things. Let us consider in more detail the purpose of these elements in the dishwasher and the principles of their replacement.
PMM working principle
The circulation pump is used to pump water into the system. He constantly works, pumping and supplying water to the rocker arms, from where it flies out under high pressure. The detergent dispenser opens immediately and the leftover food is washed off into the drip tray, from where it enters the filter. The waste water is again cleaned and fed to the nozzles. Therefore, the pump is also called recirculation.
A common cause of a breakdown in the recirculation unit is leakage. Water enters the bushings, leaches the grease, which leads to wear.
The pump drains the waste water, taking it outside the hopper. After the end of the cycle, the control board gives it a signal for pumping out. The impeller is considered the most vulnerable. Around it is often wound hair, threads that block the mechanism, so it is important to carry out periodic cleaning.
When a pump needs repair
The dishwasher works, but the water does not circulate after dialing, the dishes do not wash. At the same time, you can hear the engine humming. First check:
- Inlet filters - when clogged, they are washed under pressure from a tap;
- Nozzles - remove the rocker arms from the seats and check their holes; if they are clogged, take a toothpick and clean the aisles.
If the water in the machine does not heat up, and the flowing heater is in order, then the engine must be replaced.
Does the Candy or Zanussi PMM drain pump constantly work and does not turn off? There may be several reasons:
- Problems with the electronic board or wiring. Perhaps the pump triac is broken, or the wires are damaged and do not transmit a shutdown signal.
- Failure of the pressure switch. The level sensor monitors the amount of water in the tank, and then sends a signal to the board to stop dialing. If the sensor transmits incorrect readings that there is still water left in the hopper, the pump does not turn off.
- The dishwasher is not level. For example, the Electrolux models are very sensitive to tilts of more than two degrees.
- Incorrect connection to the sewer leads to a siphon effect. The drains flow back into the machine and the pump has to pump them out.
- The pump itself broke.
The PMM engine and its components cannot be repaired, so a complete replacement will be required. When choosing replacement parts, consider the following factors:
- the real cost of components (the most expensive are parts for Bosch dishwashers);
- originality - the spare part should fit your dishwasher model.
In Bosch machines, the pump is located next to the engine. Whereas in the technology of other brands (Hansa, Siemens) - from above.
How to check and replace the drain and circulation pumps
Prepare the entire repair kit so that parts and tools are at hand. You will need:
- pliers;
- set of slotted screwdrivers;
- awl;
- multimeter for diagnostics.
Immediately you need to check and unlock the impeller. How to clean the pump:
- Disconnect the PMM from the network.
- Open the hopper door.
- Remove the basket for dishes.
- Pull out the drain filter. You can clean it from clogging with a brush under the pressure of water.
- Take a sponge and pump water out of the filter hole.
- Pull on the pump cover (if there are screws, unscrew).
- Put on gloves and feel the impeller. Remove foreign objects.
To change the engine or pump, you have to disassemble the dishwasher. The disassembly principle is similar for almost all manufacturers. We will describe the general sequence of work, and detailed instructions can be found in a separate article.
- Unplug the plug, unplug the dishwasher from the communications.
- Open the door and remove all the baskets.
- Pull out the drain filter.
- Unscrew the fastenings of the side walls of the PMM.
- Remove thermal insulation.
- Place an old blanket or towel and turn the equipment on its side (on the back).
- Disconnect the inlet hose.
- Remove the bottom. It can be mounted on screws or latches.
- Disconnect the engine and pump wiring.
- To remove the drain pump, hold it in your hand and turn it counterclockwise.
You removed the pump, now you need to remove the circulation pump:
- Disconnect the drain pipe from the circulation unit.
- Remove the part from the mount and pull it out of the machine.
- Unscrew the inlet hose.
We recommend photographing the connectors before disconnecting the wiring. In the future, it will be easier for you to connect them.
If you find a leak, you may need to replace the recirculation unit bushings. To do this, disassemble the engine:
- remove the upper part of the block by turning it to the right;
- the lower sector is non-separable, so let's deal with the upper part;
- inside you will notice damaged bushings and traces of working out;
- if you can’t pick up the bushings in the store, you will have to order parts from a locksmith;
- replace the elements and assemble the unit.
To check the electronic part, connect the multimeter probes to the motor contacts. Resistance on the screen should tell you whether the element is working or not.
Repair is not difficult to do with your own hands, the main thing is to adhere to the recommendations. Disassembling equipment takes the most time - in total, you must manage in half an hour or an hour. If you did not repair before, then it is better to contact a specialist.
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