When the refrigerator Indesit stops freezing or, conversely, begins to turn food into ice blocks, the first The thermostat becomes a suspicious element. It is this small component that is responsible for turning the compressor on and off, maintaining the set temperature. Understanding what the Indesit refrigerator thermostat looks like is the first step to self-diagnosis of the malfunction, allowing you to distinguish a burnt sensor from problems with the refrigerant.
The appearance of this device may vary significantly depending on the year of your model and the type of control - mechanical or electronic. In older models you will see a bulky mechanism with a capillary tube, while in modern No Frost systems this may be a compact electronic sensor. Differences in design directly affect the method of inspection and replacement, so visual identification here is critical for correct repair.
In this article we will analyze in detail the anatomy of thermostats used in technology Indesit, consider their location in various series and learn how to identify signs of failure. You will find out why one sensor can cost three times more than another and whether it is possible to install an analogue from another manufacturer without loss of functionality.
Design features of mechanical thermostats
The classic mechanical thermostat, which is most often found in single-chamber refrigerators and old two-chamber models Indesit, is a sealed unit. Its main elements are a bellows (bag) filled with a temperature-sensitive gas and a long thin capillary tube. It is this tube, often enclosed in a metal braid, that is inserted directly into the evaporator or pressed against the chamber wall, transmitting temperature fluctuations to the bellows.
A rotary knob with graduation is usually located on the device body, allowing the user to adjust the degree of compression of the spring inside the mechanism. Inside the housing there is a group of electrical contacts that open or close when the gas pressure in the bellows changes. If you open such a thermostat, you will see a complex system of levers and springs that provides a clear click-like switching.
It is important to note that the capillary tube is the most vulnerable point of the design. Deformation or damage to this tube during installation leads to leakage of filler gas, after which the thermostat stops responding to temperature changes. The length of the tube can vary from 0.5 to 2.5 meters, which must be taken into account when selecting replacement parts.
⚠️ Attention: When installing a new mechanical thermostat, it is strictly forbidden to bend the capillary tube at an acute angle or twist it into a knot. This will instantly disrupt the integrity of the system and will disable the new part even before the first turn on.
Why does the thermostat click?
A mechanical thermostat makes a characteristic click when the contacts open or close. This sound is a normal operating sign. However, if the clicks become too frequent (every 10-15 seconds) and are accompanied by short starts of the compressor, this indicates “sticking” of the contacts or loss of tightness of the bellows.
Electronic temperature sensors in No Frost systems
Modern refrigerators Indesit s system No Frost and electronic control, bulky mechanical units were abandoned in favor of compact electronic thermistors. Externally, such a sensor looks like a small plastic or metal cylinder (often white, black or gray) with a diameter of about 5-8 mm, from which two wires extend, combined into a common insulation.
The principle of operation here is based on a change in the electrical resistance of the semiconductor material depending on temperature. Such sensors, often called NTC thermistors, are highly accurate and responsive. Unlike mechanics, they do not have moving parts, which theoretically increases their service life, but they are more sensitive to power surges in the network.
In refrigerators Indesit several such sensors can be used simultaneously: one monitors the temperature in the refrigerator compartment, another in the freezer, and the third can monitor the temperature of the evaporator to control the defrost system. Visually, they may be identical, but have different resistance ratings, so when replacing, it is important to check the markings.
The location of electronic sensors in Indesit is often hidden behind plastic panels. For example, the refrigerator compartment sensor may be built into the back wall or located near the fan. To access them, partial disassembly of the internal space is often required, which distinguishes them from mechanical analogues, the handle of which is located outside.
Location of the thermostat in different Indesit models
Finding a thermostat is a task that is solved differently depending on the series of your refrigerator. In classic two-chamber models with one compressor and mechanical control, the regulator knob is usually located inside the refrigerator compartment. It can be mounted in the ceiling of the chamber, in the side wall, or located on the front panel of the door if the control is placed outside.
If the handle is located inside, then the thermostat body itself is hidden behind a plastic cover or directly in the cabinet wall. To get to it, you often have to remove the lamp cover or the top cover of the camera. In models with electronic control, there is a display on the door, and the temperature sensors themselves are scattered throughout the internal volume and do not have controls accessible to the user.
In models of the series Indesit C and Indesit ER the thermostat is often located above the doorway of the refrigerator compartment or in the corner at the top. In more modern series, such as Indesit DF or EF, preference is given to electronics, where sensors are built into the air duct system.
To accurately determine the installation location in your model, it is best to use technical documentation or disassembly diagrams, since engineers Indesit could change the layout even within one series to different ones years of manufacture.
Visual table: Comparison of thermostat types
To systematize the information and finally understand what the part you are looking for looks like in your case, we suggest comparing the main characteristics of mechanical and electronic regulators used in refrigerators Indesit.
| Characteristics | Mechanical thermostat | Electronic sensor (NTC) |
|---|---|---|
| Appearance | Box with a handle and a long tube | Small cylinder on a wire |
| Operation principle | Gas expansion in the bellows | Change in resistance |
| Accuracy | Medium (error 2-3°C) | High (error 0.5-1°C) |
| Maintainability | Practically not repairable | Replacement with a module |
| Typical malfunction | Broken tube or stuck contacts | Change in resistance or open circuit |
The table shows that electronic systems they provide more stable storage of products, but their diagnostics require a multimeter and knowledge of the nominal resistance at a specific temperature. Mechanical systems are easier to understand visually, but they are less accurate.
Symptoms of malfunction and diagnostic methods
Understanding what a working thermostat looks like will not help if you do not know how to identify its breakdown. The main symptom of a mechanical regulator failure is the absence of a characteristic click when turning the knob. If you turn the knob from minimum to maximum, but the compressor does not start and there is no click, most likely the contacts are not closing.
Another common symptom is that the refrigerator does not turn off at all. The compressor hums continuously, a “coat” or ice crust freezes, and the food in the refrigerator freezes. This indicates that the thermostat contacts are “stuck” in the closed state or the bellows has lost its tightness and does not open the circuit when a low temperature is reached.
Visual inspection is not enough to diagnose the electronic sensor. You need to test it with a multimeter in resistance measurement mode. At room temperature, a working thermistor Indesit usually shows a resistance in the range from 4 to 6 kOhm (specific values depend on the model). When cooling (for example, if you hold the sensor in your hand or put it in the refrigerator), the resistance should change smoothly.
⚠️ Attention: Do not try to test electronic sensors by “short-circuiting” the wires, as is sometimes done with mechanical ones. This can lead to the combustion of the electronic control module of the refrigerator.
It is also worth paying attention to the condition of the wires going to the thermostat. In old refrigerators Indesit the insulation of wires in the area of the door hinge or exit from the case is often frayed, which causes short circuits or loss of contact.
Replacement process: step-by-step instructions
Replacing the thermostat in the refrigerator Indesit - procedure, accessible to the home craftsman, but requiring accuracy. Before starting any work, you must completely de-energize the appliance by removing the plug from the socket. This is a basic safety rule, ignoring which may result in electric shock.
Next, you should remove the decorative panels that hide the thermostat. In mechanical models, after removing the handle and plastic cover, you will see the unit itself. Disconnect the wires (after photographing the connection diagram) and carefully remove the capillary tube from the evaporator. Installing the new one is done in the reverse order, and the tube must be positioned in the same way as the old one was, avoiding kinks.
☑️ Checklist before replacing the thermostat
In the case of electronic sensors, the process often involves Removing the back wall of the refrigerator or freezer. The sensor can be fixed in a special groove or holder. When replacing, it is important to use a heat-resistant lubricant to contact the sensor with the surface of the evaporator (if the design implies this) to ensure correct temperature transfer.
After assembling and turning on the refrigerator, let it work for several hours without loading food. This will allow the system to enter operating mode and make sure that the new thermostat correctly controls the on and off cycles of the compressor.
Can I use a thermostat from another brand?
Technically install a thermostat from Atlant, Stinol or Danfoss in Indesit possible if the dimensions, length of the capillary tube and temperature range of operation match. However, the factory settings may differ, resulting in incorrect operation (too frequent startup or insufficient cooling). It is better to look for original spare parts or specialized analogues marked K59 or TAM for mechanics.
Why does the new thermostat not click?
If you installed a new mechanical thermostat and there is no click, you may not have fully turned the adjustment knob. In some models, the first click occurs only when the handle is turned to its extreme position. Also, the reason may be a defective new part or incorrect installation of a capillary tube that does not sense temperature.
How can you tell that the problem is in the thermostat and not in the compressor?
The easiest way is to short-circuit the wires going to the thermostat (for mechanics), bypassing the regulator itself. If, when shorted, the compressor starts and the refrigerator starts to freeze, then the problem is in the thermostat. If the compressor hums, but does not start, or is silent, the problem may be in the start relay, compressor, or wiring.
Do you need to defrost the refrigerator before replacing it?
Yes, complete defrosting is required. Moisture that gets on the electrical contacts or inside the new thermostat during installation can cause a short circuit or corrosion. In addition, in a defrosted state, it is easier and safer to manipulate plastic elements and evaporator tubes.