If, at the end of the program, you take out dishes that are dirty and cold to the touch from the tank, this means that the dishwasher does not heat water or does not heat it well enough, but it also does not dry. It’s too early to sound the alarm, because some failures, due to which the water does not heat up, can be eliminated without the help of the wizard:
- The machine is in use for the first time. Perhaps the equipment is not installed correctly, which is why water is constantly being collected and drained, so the heater does not have time to warm it up, the heating time has been increased. To fix the problem, ask a specialist to properly connect the dishwasher or do it yourself, observing the installation rules.
- Error mode. There are cycles in which the water does not warm above 40 degrees (with delicate washing). There is a problem in the PMM of the electromechanical type: when the program is set to 30 degrees, and the position of the selector wheel is at a temperature of 90, the washing will go according to the selected program; water does not warm above 30 degrees. Information about the modes can be easily found in a separate article or in the user manual.
- When the filter is clogged, the water circulation decreases, because of which the heater does not start and does not heat the water. You need to clean the filter and add this procedure to the list of regular household chores, otherwise the PMM will still wash your dishes with cold water - and this is time wasted, washing products, resources: water and electricity.
Important! We are often asked whether it is possible to use a machine with idle heating. It all depends on whether your dishwasher works without hot water. If the quality of washing is satisfactory, then for some time, before replacing parts, you can continue to operate at your own risk.
If, among the reasons described above, you have not found what prevents your dishwasher from heating water, then it means a breakdown.
Water does not heat up: causes and description of the problem
The main reasons why the equipment stopped heating water normally:
Crash | Description of the problem |
The heater burned out. | In the design of the PMM there is a flowing water heater or more often a heating element. Externally, the part resembles the one that is installed in the washers, and works on the principle of an electric kettle. Due to hard water, over time it becomes covered with a thick layer of scale and fails. It is impossible to repair the part - replacement with the original analogue is required. |
The temperature sensor (sensor, thermostat) has broken. | The sensor is present in the design of any dishwasher. It is a sensor that detects the temperature of water and communicates the received data to an electronic circuit board. If the process is violated, the command unit does not start the heater; the machine washes dishes without hot water. Repair of the thermostat is not possible; it must be replaced. |
The electronic control module is malfunctioning. | Electronic PMMs are equipped with a “brain” - an electronic board that analyzes the information coming from various nodes of the device and gives commands to turn them on / off. If the machine has stopped heating water, it is possible that the module has failed and does not start the heater. It is necessary to flash the electronic board or replace the unit with a new one. |
How to check and repair the temperature sensor, control board
The temperature sensor is a weak element in the design of the dishwasher, especially with Bosch brands. To understand that a temperature sensor has failed, and not another part, proceed as follows:
- Arm yourself with tools: a tester (multimeter), screwdrivers and pliers.
- Disconnect the equipment from the water supply and sewage system (be sure to close the taps on the pipes themselves).
- Disconnect power to the appliance.
- Remove the dish baskets.
- Remove the lower nozzle, the "garbage" filter and the mesh, unscrew the two fasteners that you will find under it.
- Turn the machine upside down and remove the fasteners on the sides.
- Disconnect the drain pipe from the block in which the heater is located, and raise the bottom of the PMM up.
- The sensor is located inside the body of the water heating unit - this design is due to the need to transfer data to the control unit.
- Disconnect the wires from the terminals of the thermistor.
- Strip the contacts and use a tester to measure the resistance level of the sensor.
- If it became clear that the element burned out, do not install it back, but carry it to the store to pick up a similar one.
- Install a new element in the same way as you removed it - all actions are carried out in the reverse order.
Important! Often, it is not the temperature sensor that is faulty, but its wiring. If everything is in order with the sensor (and heater), it is worth looking for a problem in the electronic module.
In 1 out of 100 case it happens that the heater is working properly (according to the tester), everything is fine with the sensor and the wiring is in order. Checking the system for blockages showed that everything is fine, the pressure is normal, and the machine continues to wash with cold water. What is the reason, what to do? In this case, the probability of failure of the electronic unit is high: most likely, not all at once, but of a separate part - the triac.
We do not recommend that you repair your expensive part yourself. To fix the board, you need knowledge in the field of electronics, experience and special tools. If it fails, you will have to buy a new module, and its cost often amounts to half the price of the PMM.
How to check the heater
In modern dishwashers Electrolux, AEG or Neff, there is a “smart” self-diagnosis system that can detect the slightest malfunctions in time. But you can’t 100% rely on it - sometimes the machine heats badly or does not heat water at all, and error codes do not appear on the screen. It is worth starting an independent search for the cause of the malfunction. To check if the heater is working, proceed as follows:
- Place the case upside down.
- Unscrew the back wall (if you do not have a built-in model) or remove the panel from the bottom (in the built-in version). To remove it, disconnect the drain pipe from the water heating unit and pull the panel towards you.
Attention! Do not remove it at all - this is optional, and it will not work without removing the mounts.
- If you already checked the sensor according to the previous instructions, you need to disassemble the dishwasher further to diagnose the heater.
What will be needed to replace
Any part, including the heater, in such brands of dishwashers as Indesit or Electrolux, requires a complete replacement. The heater cannot be repaired - it is easier to unscrew and discard the part, replacing it with a new one.
Prepare tools for work:
- Phillips, slotted screwdriver;
- tester;
- pliers;
- ordinary awl.
Before buying a heating unit, make sure that the heater is faulty - it may not be in it. The difficulty is that in the above brands of PMM it is impossible to separately replace the part, you need to install the entire unit, but it costs more.
The heating unit is located in a plastic case, in which there are bends for pipes and outputs for sensors. If you did not find fasteners that make it clear that the unit is being disassembled, it means that a separate heater cannot be replaced. If the unit can be disassembled, it will turn out to replace the heating element separately from the entire part.
Important! A non-separable type block for Bosch cars costs from 3,000 to 10,000 rubles, for Indesit and Electrolux - an order of magnitude cheaper.
How to replace the heater
If the problem is in the heater, buy a part and replace the heater. Before that, consider how profitable the repair will be: if the PMM is old and more than 10,000 rubles will not be given for it, then buying a spare part is not profitable. But the decision to make you.
How to replace the heater:
- Open the hopper, remove the baskets.
- Disconnect the machine, remove the hoses.
- Remove the sprayer.
- Unscrew the filter.
- Remove the stainless mesh.
- Unscrew the fastenings on which the pipe and instantaneous water heater are held.
- Turn the appliance upside down.
- Turn the pump half a turn to the right and pull to remove the part.
- Remove the sensor, set the pump aside.
- The flow heater is held onto a rubber mount. Find fasteners and disconnect.
- Then remove the sensor plugs, pipes and get the blown heater.
- Install a new part, assemble the machine, acting in the reverse order.
Now you know why your PMM does not heat water. We made a repair manual using leading brands as an example, but cars of other brands such as Coopersberg, Ariston or Abbot are repaired on a similar basis.