Why does the dishwasher wash with cold water?

When your dishwasher doesn't heat the water, it becomes very difficult to use. The dishes remain dirty, so the owners try to quickly find out the reason for this behavior of the “home assistant”. You can deal with a number of problems yourself at home; some can only be fixed through a service center. Let's figure out why there may be no heating in the PMM.

What is this problem?

When the dishwasher is washed with cold water, there is no need to immediately disassemble its body in search of a problem. If the machine is new, then first of all check whether it is properly connected to the water supply. Some models have two outlets for the inlet hose, one “hot” and the other “cold”. If the points are mixed up during the installation process, the PMM will not heat the liquid in the system.

If you mistakenly connect the inlet hose to the “hot” outlet, the “brain” of the machine will think that warm water is being poured into the system. Therefore, he will not warm it up. Fixing the problem is very simple, you just need to connect the corrugation to the “cold” terminal.

Perhaps the dishwasher does not heat the water due to the user choosing the wrong program.

For example, having launched the delicate mode for very dirty dishes, the user is not satisfied that the machine did not completely wash the cutlery. After touching the plates and forks, he notices that the cutlery is cold. From this it is concluded that the dishwasher is not heating the water. You can view the parameters of each program in the equipment instructions.

Another possible cause is a clogged dishwasher filter.This provokes a circulation disorder, and the machine washes the dishes with cool water, and even intermittently. Therefore, the user’s task is to clean the filter element from food residues in a timely manner, avoiding such situations.

If you are confident that no errors were made during the operation of the machine, you will have to engage in in-depth diagnostics of the dishwasher. The cause of the problem may be:

• Broken thermistor. This is a common problem with many dishwashers. Due to a damaged thermistor, the control module receives false information about the degree of water in the working chamber. In such a situation, the “brain” does not turn on the heating element, so the water in the bunker remains cold. To fix the problem, you will need to replace the sensor.
• Failed heating element. In modern PMMs, the heater is combined with a recirculation pump. If the heating element breaks, the entire unit must be replaced. Fortunately, such a malfunction occurs extremely rarely.
• Damaged control module. The PMM board is “studded” with a large number of semiconductors. When the element responsible for communication with the heating element or temperature sensor fails, the machine stops heating the water. It is better to entrust the solution to the problem to the service center specialists.

Damaged wiring may also be the cause. Even if one cable frays or jumps out of the chip, the power supply to the heating element, temperature sensor or recirculation pump will be disrupted. The machine will stop heating water during the cycle.

It is quite possible to replace failed elements with your own hands. You will have to contact the service center specialists if there are problems with the control module. You shouldn’t “dig” into the dishwasher’s electronics without sufficient experience and knowledge. This could cause further damage to the equipment.

How to find the source of the problem?

To find out the cause of the problem, you will have to diagnose the dishwasher. To check the PMM parts you will need a multimeter. Using the device, it is necessary to measure the indicators produced by the thermostat, heating element and pump.

Before starting disassembly, de-energize the PMM and disconnect it from the water supply and sewerage system. Next, remove the dishwasher tray - this is where all the “suspect” parts are located. It is better not to go into the control module - repairing it requires special knowledge.

Disconnect the chip with wires from the recirculation pump and measure the resistance at the input with a tester. Normally, the indicator for a working pump together with the heating element should be approximately 25 Ohms (a deviation of plus/minus 5 Ohms is allowed). If the value is less, it means the element is not functioning correctly and needs to be changed.

Then run diagnostics on the temperature sensor. Disconnect the wiring from it and measure the resistance of the contacts. The tester should produce a value in the range of 4700-6000 Ohms. If the number does not correspond to the standard, it means that the thermostat is faulty and needs to be replaced.

If everything is in order with the pump, heating element and temperature sensor, carefully inspect the wiring. It may be possible to detect burnt or worn areas. Also make sure that no cable is coming off the chips.

When visually everything is in order with the wiring, arm yourself with a multimeter and check each cable for breakdown. It is likely that the wiring has burnt out or is broken under the insulation, and therefore cannot function correctly. If you find a problem, fix it.

What to do after detecting a problem?

What to do after detecting a breakdown? Some “do-it-yourselfers” advise trying to restore the heater in the recirculation pump. According to experts, such repairs are quite doubtful. The best way out is to change the entire assembly.

When purchasing new components, pay attention to the PMM model and the factory markings of the parts themselves.

There is a number on the body of the recirculation pump. It is necessary to order a part with the same markings. Next, it will be enough to dismantle the old pump and install a new unit, connecting all contacts to it.

You should do the same with the temperature sensor. Buy a new thermostat and install it in place of the broken one. If these elements are in working order and suspicions fall on the control module, contact a service center for help. Specialists will competently diagnose the electronic unit.

   

Reader comments

• Share your opinion - leave a comment