Failure of the temperature control system is one of the most common reasons for contacting service when it comes to household appliances brand Ariston. If you notice that the food in the refrigerator compartment has begun to freeze, or, conversely, the temperature inside has risen above the permissible values, the first thing you should do is check thermostat. It is this component that is responsible for maintaining a given microclimate, turning the compressor on and off as needed.
Many owners mistakenly believe that in order to diagnose or replace this unit, it is necessary to completely disassemble the entire unit or call a technician. In fact, in most models Ariston access to the thermostat is quite simple and does not require specialized tools other than a screwdriver. Understanding exactly where the sensor is located will help you save time and money on DIY repairs, as well as quickly diagnose the problem.
In this article we will analyze in detail the design features of various modifications of refrigerators so that you know exactly where to look. We will consider both classic mechanical models and more modern electronically controlled options, where thermostat functions can be distributed among several sensors. Be careful, as incorrect diagnosis can lead to the purchase of unnecessary spare parts.
The principle of operation and the role of the thermostat in the cooling system
The thermostat, or thermostat, is an electromechanical or electronic device that continuously reads the temperature inside the refrigeration chamber. Based on the data received, it closes or opens the electrical circuit that supplies power to compressor. In mechanical models, this process occurs due to the expansion and compression of gas or liquid inside a bellows connected to a capillary tube.
When you turn the adjustment knob, you change the degree of spring tension or the position of the contacts, which shifts the temperature thresholds. If the chamber becomes warmer than the set limit, the contacts close, starting the motor. When the desired cold is reached, the circuit opens and the unit goes into standby mode. Violation of this cycle often indicates wear of internal components or loss of system tightness.
⚠️ Attention: If your refrigerator Ariston works without stopping or, conversely, does not turn on at all, do not rush to change the compressor. In 80% of cases, the problem lies precisely in a faulty thermostat or a break in its capillary tube.
It is worth noting that in two-chamber models, the thermostat usually controls the temperature only in the refrigerator compartment. The freezer compartment is cooled according to the residual principle or has its own separate sensor, but the main cycle of the motor operation is set precisely by the upper compartment. Therefore, a malfunction of the regulator often manifests itself in the form of an ice crust on the food in the main chamber or complete defrosting of the entire contents.
Types of thermostats in Ariston refrigerators
The company Ariston over the years of production has used various types of temperature control systems, which is important to consider when searching for a part. In older and budget models, mechanical thermostats are most often found, which are easily identified by the presence of a rotary knob with numbers or divisions inside the chamber. Such devices, as a rule, are marked with manufacturer codes TAM, K or RANCO.
More modern lines can be equipped with electronic thermostats. They have no moving mechanical parts, and temperature data is read by semiconductor sensors. The location of such elements may vary: they are often built into the chamber wall or hidden behind decorative panels. Electronics provide more precise adjustment, but are more difficult to diagnose without special equipment.
- 🔧 Mechanical: have a capillary tube that goes into the evaporator and are controlled by turning the handle.
- 📟 Electronic: they are a small sensor on a wire that transmits a signal to the control module.
- ❄️ Combined: in some models Ariston No Frost a mechanical thermostat can control the evaporator, and an electronic thermostat can control the overall temperature.
You can determine the type of your device by looking at the control panel inside the refrigerator. If there is a handle that you can turn, you have a mechanic. If there are only buttons or a display, most likely it is electronics, although in some cases the handle can be simply decorative and control a potentiometer.
Is it possible to replace mechanics with electronics?
Theoretically it is possible, but this requires a deep rework of the control system, changing the wiring and installing a new control unit. It is easier and cheaper to find an original analogue of a mechanical thermostat.
Where is the thermostat located: main locations
Searching for a thermostat in the refrigerator Ariston depends on the year of manufacture and the specific series of the model. In the vast majority of classic models, this element is located inside the refrigerator compartment. Most often it is located in the upper right or left corner, closer to the lampshade. The regulator handle is brought out, and the body itself is hidden behind a plastic cover.
In models with the system No Frost the situation may be different. The thermostat is often hidden behind the back wall of the refrigerator compartment or in a niche above the door. The capillary tube in such units goes to the evaporator, which is hidden behind the panel. To get to it, sometimes partial disassembly of the interior is required, including the removal of shelves and containers.
⚠️ Attention: In some modifications Ariston the thermostat can be installed outside, on the back wall of the refrigerator case, near the compressor. This is typical for built-in models or equipment where the internal space is as limited as possible.
To accurately determine the installation location, it is recommended to look at the technical data sheet of the device or find the markings on the thermostat itself if its shank is visible. It may also be helpful to search for a photo of your model on the Internet, where enthusiasts often post disassembly diagrams.
Instructions for dismantling and accessing the thermostat
Before starting disassembly, be sure to unplug the refrigerator from the power supply. Safety is paramount as you will be working with electrical components. After this, empty the refrigerator compartment of food and remove any shelves that may interfere with access to the top of the unit.
If the thermostat is located under the adjustment knob, carefully pry up the plastic trim around it with a flat-head screwdriver. It is often held in place by latches, which can be quite tight. After removing the decorative panel, you will see the thermostat housing and the wires that go to it. In some models Ariston you will need to remove the lamp shade, since the thermostat is mounted next to it.
☑️ Preparation for dismantling
To remove the device you will need to unscrew the mounting screws, if any, and carefully pull them out thermostat Be careful with the capillary tube: it is very thin and easily damaged. If the tube accidentally gets pinched or bursts, gas will escape and the new thermostat will not work correctly. In models where access is difficult, you may need to remove the top cover of the refrigerator.
Diagnostics of thermostat malfunctions
After removing or gaining access to the thermostat contacts, you need to check its functionality. The easiest way is a visual inspection for melting, oxidation of contacts or damage to the wire insulation. However, external integrity does not guarantee the serviceability of internal mechanics or electronics.
For accurate diagnostics, use multimeter, switched to the circuit continuity mode. Disconnect the wires from the thermostat terminals and connect the probes to the contacts. At room temperature, the contacts of the mechanical thermostat should be closed (the multimeter beeps). If you place the sensitive part (bellows) in the cold (for example, in the freezer for 10-15 minutes), the contacts should open.
| Symptom | Possible cause | Action |
|---|---|---|
| The refrigerator does not turn on | Open circuit of the thermostat | Check the contacts with a multimeter |
| Continuous operation of the compressor | Sticking contacts | Replace the thermostat |
| Food freezes at the back wall | Incorrect calibration | Try adjustment or replacement |
| A click is heard, but it starts no | Malfunction of the starting relay or thermostat | Diagnostics of the power circuit |
If the contacts do not open when the sensitive element is cooled, or if the circuit does not close when warm, the thermostat is faulty and requires replacement. It is also worth checking the condition of the capillary tube: there should be no creases, cracks or traces of oil on it, indicating a freon leak from the bellows.
Replacing the thermostat and adjusting the temperature
The replacement process begins with the purchase of a similar part. There is always a marking on the body of the old thermostat (for example, Ariston there is always a marking (for example, TAM 133 or K 59). Look for an exact analog or compatible model, paying attention to the length of the capillary tube and the number of contacts. Installation is carried out in the reverse order of removal.
Carefully insert the bellows with the tube into its original place, being careful not to damage its sharp edges to the metal elements of the body. Connect the wires to the appropriate terminals, referring to the photographs or color markings you took earlier. Secure the housing with screws and install the decorative handle in place.
After assembly, turn on the refrigerator. The initial startup may take longer than usual as the system needs to get up to temperature. Do not load the camera with food during the first few hours of operation. Adjust the temperature smoothly, pausing between switching the knob to allow the system to stabilize.
⚠️ Attention: Technical characteristics and arrangement of elements may vary slightly depending on the specific production batch. Always check the connection diagram on the new device with the markings on the wires of your refrigerator.
If the problem does not disappear after replacement, the fault may lie in another component, for example, in the compressor start relay or a refrigerant leak. In this case, further diagnostics require more in-depth knowledge and tools.
How often do you need to change the thermostat in an Ariston refrigerator?
The thermostat does not have a strict expiration date and is changed only after a breakdown. With careful use, it can last 10-15 years or more. Frequent power surges in the network can shorten its service life.
Is it possible to temporarily close the thermostat contacts?
Yes, this will allow you to start the compressor to check other components, but you cannot leave the refrigerator in this mode for a long time. The compressor will work continuously, which will lead to deep freezing of food and possible failure of the motor.
Why does the refrigerator freeze less weakly after replacing the thermostat?
Perhaps the capillary tube of the new thermostat is not immersed deep enough in the evaporator or is in poor contact with it. Also, the reason may be incorrect adjustment or a defective new part.
Where can I find the refrigerator model marking?
Usually the nameplate with the model and serial number is located inside the refrigerator compartment on the side wall, on the rear wall outside or on the base below. Technical parameters and release date are also often indicated there.