When the number 15 light on your dishwasher's control panel lights up, this is a signal that the system has detected a problem with the water pumping process. Equipment owners Hotpoint Ariston We often encounter this situation when the wash cycle is completed, but liquid remains inside, or the device refuses to start the program at all. This code is not fatal, but it cannot be ignored, since regular stagnation of water can lead to an unpleasant odor or damage to the pump.
The self-diagnosis system of modern dishwashers is designed in such a way that it continuously monitors the water level in the working chamber. If the sensors detect that the liquid has not left after the allotted time, the controller blocks further operations and issues a corresponding signal. Understanding what exactly it means error 15, will help you save time and money by performing initial diagnostics yourself, without calling a specialist.
In most cases, the problem lies in simple blockages or kinks in the hoses, which can be easily fixed. However, sometimes the reason may lie in a malfunction of electrical components, such as a pump or pressure switch. Our task is to consistently eliminate simple options before moving on to complex repairs. Below we will analyze in detail the algorithm of actions and technical nuances that every owner of this equipment needs to know.
Decoding the code and operating principle of the drain system
Error code 15 on the display or in the form of a lit indicator indicates that the machine cannot pump water out of the tank. This state is recorded by an electronic module, which receives data from a water level sensor (pressostat). If, after the time allotted for draining, the liquid level does not drop to a critical level, the program is interrupted. It is important to understand that in different models Ariston the indication may differ: in some places only the number is lit, and in others the shower or faucet symbol flashes in combination with the number 15.
The operating principle of the drainage system is quite simple, but requires precise coordination of all components. After completing the rinsing or washing phase, the solenoid valve opens (if it is included in the design) or immediately turns on drain pump. Water under pressure passes through the filters, then goes through a corrugated hose into the sewer. If there is resistance along any part of this path, the pump continues to operate, but the water remains inside. It is this moment that is recorded as an emergency situation.
⚠️ Attention: Do not try to forcefully restart the program many times in a row if the water is standing in the tank. This can lead to overheating of the drain pump motor winding and its final failure.
It is worth noting that some models are equipped with an AquaStop system or similar protection against leaks. If error 15 is accompanied by a humming sound or unusual sounds, this may indicate that water has entered the pan of the machine and the protection has tripped. In this case, the electronics block the intake of new water until the cause of moisture entering the lower part of the housing is eliminated. Diagnosis in this case requires a careful examination of the internal cavities.
Primary visual diagnostics and testing of communications
Before disassembling equipment or looking for spare parts, it is necessary to conduct an external inspection of communications. Often the reason lies not in the machine itself, but in the organization of the drain. Check if it is kinked drain hose behind the back wall of the dishwasher. When installing equipment, the hose could be pressed too tightly against the wall or squeezed by a furniture leg, which created a mechanical barrier to the flow of water.
Next, you should pay attention to the place of insertion into the sewer. If the drain hose is connected to the sink trap, make sure that this unit is not clogged with food waste. A clog in a common drain line can create a back-pressure effect that can even cause water from the sink or other sources to flow back into the dishwasher. This is a common problem in older homes with narrow pipes.
Check the height of the drain hose connection. It must be raised to a height of 60-80 cm from the floor before descending into the sewer to prevent the gravity of water and the reverse suction of dirty liquid.
It is also worth checking the condition of the surge protector and socket. Unstable voltage in the network sometimes leads to malfunctions of the electronic module, which can incorrectly interpret data from sensors. Although this happens less often than a banal blockage, the electrical factor cannot be completely ruled out. If you notice that the error occurs sporadically (periodically), try plugging the machine into a different outlet.
Cleaning the filters and drain pipe
The most common reason for code 15 is a dirty filtration system. At the bottom of the dishwasher chamber Hotpoint Ariston There is a mesh structure consisting of coarse and fine filters. Their job is to trap food debris, bones and other debris, preventing them from entering the pump. Over time, this layer becomes dense and impermeable to water.
The filters must be removed for cleaning. They usually unscrew counterclockwise. Rinse them under a strong stream of hot water, using a soft brush to remove any grease deposits. Grease is an insidious enemy and may not wash off with cold water, so it is recommended to use a dish degreaser. While the filters are drying, look into the hole underneath them.
☑️ Cleaning the filtration system
If you find large objects under the filter (toothpicks, glass fragments, seeds), they must be carefully removed with tweezers. It's also worth checking the drain pipe, which is located deeper, often under the bottom of the car or behind the bottom panel. Disconnect the hose from the pump and check its permeability by blowing it out or pouring water on it. Often it is in the bends of this pipe that small objects that pass through the filter get stuck.
Diagnostics and testing of the drain pump (pump)
If the filters are clean and the hose is free, attention turns to the drain pump. This is the heart of the drainage system. To check it, you need to gain access to the underside of the machine. In some models, it is enough to remove the bottom plinth; in others, you will have to lay the dishwasher on its side (after draining the water). Find the pump: it is a plastic cylinder with an impeller inside.
Visually inspect the impeller. Try turning it with your finger (after turning off the power to the car!). It should rotate freely, without jamming. If resistance is felt or a crunching sound is heard, a foreign object may have gotten into the mechanism or the shaft bearings may have worn out. Sometimes threads from sponges or hairs are wound there, blocking rotation.
How to check the integrity of the pump winding?
For this you will need a multimeter. It is necessary to remove the terminals from the pump contacts and switch the device to resistance measurement mode (Ohms). The normal winding resistance of a working pump is usually from 150 to 200 ohms. If the device shows one (open) or zero (short circuit), the pump needs to be replaced.
It is also worth checking the wires going to the pump. Make sure that the contacts are not oxidized and are securely fixed. If you hear a hum when you turn on the drain mode, but the impeller does not spin, this is a sure sign that the motor is trying to work, but is mechanically blocked or has failed. In this case pump replacement is the only solution.
Checking the electronic module and pressure switch
If the mechanical part is working properly, the problem may lie in the “brains” of the device or sensors. A pressure switch is a device that tells the control module how much water is in the tank. If it transmits incorrect data (for example, that the water has already left, although the tank is full, or vice versa), the module may display error 15. Check the tube going from the pressure switch to the tank: it should not be clogged or pinched.
The electronic control module is the most complex and expensive component. Voltage surges or moisture ingress can damage the triac that controls the pump or other elements of the board. If you see traces of burning, swollen capacitors or blackening on the board, DIY repairs are only possible if you have soldering and circuit design skills.
| Component | Signs of malfunction | Verification method |
| :--- | :--- | :--- |
| Drain pump | It hums, but doesn't pump / is silent / sparks | Visual inspection of the impeller, ringing with a multimeter |
| Pressostat | The machine does not “understand” the water level | Purge the tube, check the contacts |
| Electronic module | Program crashes, lack of response to buttons | Visual inspection of the board, checking the output voltage |
| Drain hose | Water goes away slowly or doesn't go away | Removing the hose and checking the water flow |
⚠️ Attention: Repairing an electronic module requires high qualifications. Incorrect actions can lead to short circuits and failure of other machine components. If you are not confident in your abilities, it is better to consult a specialist.
Error reset algorithm and testing
After all cleaning and repair work has been carried out, it is necessary to reset the error from the machine’s memory. Simply turning the power off and on is often not enough. For models Hotpoint Ariston There is a standard reset procedure. Press and hold the power button (or dedicated reset button if there is one, often indicated by a drop or crossed out circle symbol) for 3-5 seconds.
After reset, run the express wash program without dishes. Watch the draining process. If the water drains quickly and silently, and error 15 does not appear again, the problem is solved. If the situation repeats, perhaps the cause has not been completely eliminated or the malfunction is of an intermittent (floating) nature, which often happens with sensors.
A full diagnostic cycle takes about 30-40 minutes, but in 80% of cases it allows you to avoid a costly service call.
Prevention and operating rules
To error 15 on the dishwasher Hotpoint Ariston never appeared again, it is important to follow the operating rules. Always remove large food particles from plates before loading. Use special products to dissolve fat and prevent scale. Regular cleaning of filters (at least once a week) will extend the life of the pump.
It is also recommended to run a high-temperature dry cycle every few months with the addition of citric acid or a special dishwasher cleaner. This will help dissolve fatty deposits in hidden cavities and hoses that are not visible during normal inspection.
Use dishwasher salt even if the water is soft. This will prevent limescale from forming on the heating element and internal parts, maintaining their efficiency for years to come.
Frequently asked questions (FAQ)
Is it possible to use the dishwasher if error 15 is on?
It is not recommended to operate the machine with a drain error. The water in the tank can start to spoil, give off an unpleasant odor, and there is a risk of overflowing and flooding the kitchen if the machine tries to draw new water on top of the old one.
How much does it cost to replace a drain pump for Hotpoint Ariston?
The cost of the original pump varies depending on the model and region, usually the price ranges from 1,500 to 3,500 rubles, excluding the work of the master. Analogues may cost less, but their service life is often lower.
Why does the machine hum, but does not drain the water?
A humming sound when there is no drain most often indicates that the pump impeller is blocked by a foreign object (bone, glass) or the motor winding is burned out and it cannot develop the required force.
How often should filters be cleaned to avoid error 15?
It is recommended to carry out a visual inspection and, if necessary, clean the filters after each wash cycle or at least once every 2-3 days, especially if you are washing heavily soiled dishes.