Sudden loss of food tightness or the formation of an ice crust on the walls of the refrigerator compartment Ariston often indicates a failure in the thermoregulation system. If the compressor runs continuously without turning off, or, conversely, turns on extremely rarely, allowing the temperature to rise, then the first suspicion falls on the temperature sensor. This small element is the “eyes” of the electronic control module, informing it about the real climate inside the refrigerator and freezer chambers.
Diagnostics of the temperature sensor does not require deep engineering knowledge, but requires compliance with safety precautions and the presence of a minimum set of tools. Sensor malfunction can lead to damage to a large stock of products, so the first signs of incorrect operation of the No Frost or static cooling system cannot be ignored. In this article, we will analyze a step-by-step verification algorithm, typical symptoms of failure and methods for restoring the device's functionality.
Modern refrigerators Ariston are equipped with complex electronics, which, if the sensor fails, can block the start of the compressor or display an error on the display. Understanding how this element works will help you save time on calling a technician, or at least accurately diagnose the problem before he arrives. We will consider both visual assessment methods and instrumental diagnostics using a multimeter.
Symptoms of a thermal sensor malfunction
The first signal that thermistor has stopped reading data correctly is a change in the compressor operating mode. If you notice that the motor is humming non-stop, trying to catch up with a non-existent cold, or the pauses between starts have become abnormally long, the food in the refrigerator compartment begins to thaw, this is a direct indication of a problem with the sensor. The electronics receive false signals and cannot properly control the cooling cycle.
In models with a display, specific error codes often light up, which directly indicate the fault zone. Refrigerators Ariston are characterized by errors associated with the evaporator or air sensors in the chamber. However, you should not rely only on the indication, since a failure can be caused by oxidation of the contacts or a break in the wiring leading to the sensor.
⚠️ Attention: If you observe a complete absence of cold when the fan is running, do not rush to blame the sensor. First of all, check whether the drainage is clogged and whether the defrosting system is working, as the symptoms may be similar.
An indirect sign may be the formation of excessive ice in one of the compartments during normal operation of the other. For example, in the freezer Ariston it may be "-25°C", and in the refrigerator compartment the food begins to deteriorate due to insufficient cold, although the compressor is working properly. This indicates that air temperature sensor in the refrigeration chamber is transmitting incorrect data about cold saturation.
Where the sensor is located and how it works
In refrigerators Ariston several temperature sensors are used, located in different units of the unit. The main ones are sensors that control the air temperature in the refrigerator and freezer compartments, as well as an evaporator defrost sensor. Understanding their location is critical for correct diagnosis, since checking each of them has its own nuances.
The air sensor in the refrigerator compartment is usually hidden behind a decorative panel on the back wall or built into the control unit if the model has a remote sensor. In a freezer with a No Frost system, the sensor is often located next to the evaporator, hidden behind a plastic cover. You can get to it only by dismantling the inner lining of the chamber, which requires care.
Structurally, the sensor is thermistor with a negative temperature coefficient (NTC). This means that as the temperature rises, its electrical resistance drops, and as it cools, it increases. It is the change in resistance that is recorded by the electronic module and, based on this data, makes a decision to turn the compressor on or off.
Design features of NTC sensors
Inside the plastic case there is a ceramic element that is sensitive to heat. If there is a mechanical shock or moisture gets inside the case, the ceramic can crack, which will lead to a sharp jump in resistance and a system error. That is why you should not pull the wires when dismantling.
Necessary tools for diagnostics
To carry out a quality test, you will need a minimum set of tools that any home craftsman will have. The main device is a multimeter (tester) capable of measuring resistance in the range from 1 kOhm to 20 kOhm. Without this device, the check will be only tentative.
In addition to the multimeter, you will need screwdrivers (Phillips and flathead) to remove the panels and access the sensor. Some models Ariston may require Torx screwdrivers. It would also be a good idea to have a hairdryer or a container of hot water with you to simulate temperature changes during testing.
- 🔧 Multimeter —the main device for measuring resistance.
- 🪛 Set of screwdrivers - for disassembling the case and removing panels.
- 🌡️ Hair dryer or container with water - to check the sensor's response to heat.
- 🧤 Gloves - to protect your hands from sharp plastic edges.
It is important to make sure that the multimeter is working properly and its battery is not discharged, since measurement errors can lead to erroneous conclusions. Before starting work, be sure to disconnect the refrigerator Ariston from the electrical network to avoid short circuit or electric shock.
☑️ Preparation for diagnostics
Step-by-step instructions: checking with a multimeter
The testing process begins with access to the sensor. After turning off the power, remove the necessary panels in the chamber where the faulty element is believed to be located. Carefully disconnect the sensor connector from the electronic board or extension wire. Visually inspect the wires for breaks, melting, or signs of rodents.
Switch the multimeter to resistance measurement mode (Ohms). Connect the probes to the sensor contacts. At room temperature (about +20...+25°C), a working sensor Ariston usually shows a resistance in the range from 4 to 7 kOhm, but the exact values depend on the specific model and type of sensor. If the device shows “1” or “OL” (infinity), then there is a break in the sensor and it requires replacement.
For a more accurate check, it is necessary to create a temperature difference. You can warm up the sensor with a hairdryer (without overheating above +60°C) or, conversely, cool it. The resistance should change smoothly. If the readings on the multimeter screen stand still or jump chaotically, thermal sensor faulty.
| Environment temperature | Expected resistance (approximate) | Status sensor | Action |
|---|---|---|---|
| +25°C (Room) | 4.5 – 6.5 kOhm | Normal | Checking dynamics |
| +5°C (Cold) | 8.0 – 12.0 kOhm | Normal | Compare with table |
| Any | Infinity (OL) | Break | Replacement |
| Any | 0 Ohm | Short circuit | Replacement |
⚠️ Attention: Technical characteristics of the sensors may vary depending on the year of manufacture and model of the refrigerator Ariston. It is recommended to compare the obtained data with the official service documentation for your specific modification.
If you are not sure of your readings, you can conduct a comparative test with a known-good sensor of a similar type. Connect the reference sensor to the refrigerator wiring harness (without installing it in the chamber) and see if the system behavior changes or the error code goes away.
Typical errors and fault codes
Modern refrigerators Ariston equipped with a self-diagnosis system that displays error codes on the display or indicates their flashing lights. Understanding these codes makes it much easier to find a faulty sensor. Most often, problems with thermistors are indicated by the letter "F" or "E" in combination with a number.
For example, an error associated with the evaporator sensor may indicate that the defrost system is not receiving correct data about the heat exchanger temperature. This leads to an increase in “fur coat” and blocking of air channels. An error in the air sensor in the chamber often leads to chaotic activation of the compressor.
- ❄️ Evaporator sensor error —often leads to icing and stopping of air circulation.
- 🌡️ Camera sensor error —causes an incorrect temperature in the compartment.
- 🔌 Communication error - may mean an open circuit between the sensor and the control board.
It is worth remembering that the error code does not always mean the death of the sensor itself. The problem may lie in oxidized connector contacts, damaged wiring inside the refrigerator body, or even a malfunction of the control board itself. Therefore replacing the sensor without first checking the circuit may not solve the problem..
Replacing the temperature sensor with your own hands
If diagnostics confirmed a malfunction thermistor, it must be replaced. You can buy original spare parts for Ariston in specialized stores or order using the catalog number indicated on the sensor itself. Universal sensors are rarely suitable, since their calibration may differ.
The replacement process involves dismantling the old element. In some models, the sensor is simply inserted into a plastic groove, in others it is secured with clips or screws. Be careful when removing: the plastic housing of the sensor is fragile, and pieces of it that get into the drain or on the evaporator can cause problems in the future.
After installing the new sensor, reassemble the refrigerator in reverse order. Be sure to securely secure all connectors. When you turn it on for the first time, the refrigerator Ariston may work in test mode for some time (up to 2-3 hours), stabilizing the temperature. During this period, do not load the camera with products.
What to do if after replacement the error does not disappear?
If you replaced the sensor and the error code remains, check the integrity of the wires along the entire length to the control board. The damage may be hidden inside the insulation or broken by the door. It is also worth checking the voltage on the board connector - if it is not there, the problem may be in the control module itself.
Is it possible to use a sensor from another model?
You can use sensors from other models or brands only as a last resort and provided that their resistance at room temperature matches the original (an error of no more than 5-10% is allowed). Otherwise, the refrigerator will not work correctly, which will lead to excessive consumption of electricity or spoilage of food.
How often do you need to change the temperature sensor?
The service life of the temperature sensor is not strictly limited in time. Under normal operating conditions, it lasts as long as the refrigerator itself. Replacement is required only in case of physical breakdown, mechanical damage or natural aging of the material, leading to drift of readings.