Brand refrigeration equipment Indesit has earned popularity due to its reliability, but even time-tested equipment may require the attention of the owner. The main element responsible for maintaining a stable microclimate inside the chambers is the thermostat. It is this component that controls the cycles of turning the compressor on and off, ensuring the safety of the products. Understanding the principle of its operation helps to quickly diagnose malfunctions and avoid unnecessary calls to the technician.
The cooling system is based on a closed loop, where thermostat acts as the main control element. It continuously reads the temperature of the evaporator or air in the chamber, comparing the readings with the specified parameters. If you notice that food has begun to freeze or, conversely, to deteriorate faster than usual, the problem most often lies in the failure of this particular unit. In this article we will analyze in detail the mechanics of the device, its design features and operating nuances.
Device of different series Indesit can be equipped with regulators of various modifications, but the basic principle of their operation remains the same. Knowledge of this mechanics will allow you to independently carry out initial diagnostics and, if necessary, replace the part.
Principle of operation of the thermostat
The functioning of the thermostat is based on the physical properties of gases and liquids to change their volume when the temperature changes. Inside the sensitive tube, which is attached to the evaporator or introduced into the air flow of the chamber, there is a working substance. When the temperature drops, this substance contracts, creating pressure on the membrane, which mechanically opens the electrical contacts. As a result, the compressor stops.
When the temperature in the chamber rises above a predetermined threshold, the working substance expands. The pressure inside the bellows increases, pushing the membrane and completing the electrical circuit. The compressor starts again, starting the refrigeration cycle. This process is repeated cyclically, ensuring maintenance set temperature within the permissible error. The accuracy of operation depends on the calibration of the spring and the state of the contacts.
In models Indesit with electronic control, the role of a mechanical bellows is performed by an electronic sensor (thermistor). It changes its resistance depending on the heating, transmitting data to electronic module. The control board analyzes the signal and supplies voltage to the compressor start relay. This approach allows you to achieve higher adjustment accuracy and implement additional functions, such as fast freezing.
⚠️ Attention: Mechanical thermostats are sensitive to vibrations and shocks. A sharp shake of the case during transportation can disrupt the calibration of the spring, which will lead to incorrect operation.
Types of regulators in Indesit refrigerators
The manufacturer uses two main types of temperature control systems, depending on the model class and year of manufacture. Mechanical controls are a rotary switch with a dial, usually located inside the refrigerator compartment or on the top panel. They are simple in design and repairable, but have a large measurement error.
Electronic control systems, often found in models Indesit No Frost, require a digital display on the outside of the door. Here the user sets precise degrees, and the system automatically regulates the operation of the unit. Such systems are more difficult to diagnose, as they require special instruments for checking electronic sensors.
You can distinguish the type of control by the presence of a control knob inside the camera. If it is not there, but there is a screen on the door, then you have an electronic version. In some budget models, the mechanical regulator may be hidden behind a decorative panel on the ceiling of the chamber. It is important to know the type of your device before ordering spare parts.
Location and design of the device
In classic models Indesit with a drip defrosting system, the thermostat is most often located inside the refrigerator compartment. Its capillary tube is attached to the evaporator, hidden behind the plastic panel of the rear wall, or introduced into the air flow. The control handle is located outside for user convenience. The design includes a housing, a bellows, a spring and a contact group.
In systems No Frost temperature sensors are placed in the cold air circulation zone. There may be several of them: one controls the operation of the evaporator, another controls the temperature in the chamber, and the third monitors the defrost system. Access to them often requires partial disassembly of the interior or removal of the back cover. This complicates the process of self-replacement.
Where to look for the thermostat in older models?
In old Soviet Indesit models, the thermostat could be located outside the case, under the top cover, next to the motor. However, in most modern household refrigerators it is located inside the chamber or behind a decorative trim on the door.
Structurally, the mechanical regulator is sealed. An attempt to open its body without special equipment will lead to failure of the sensitive element due to a violation of the bellows seal. Therefore, if a mechanical thermostat breaks down, it is completely replaced with a new analogue with identical parameters.
Symptoms of a malfunctioning thermostat
You can determine that the regulator has stopped performing its functions correctly by a number of characteristic signs. The first and most obvious symptom is a violation of the temperature regime. Products can either freeze, turning into ice blocks, or, conversely, quickly deteriorate due to insufficient cooling.
Another important sign is the uncharacteristic behavior of the compressor. It can work without interruptions, trying to “catch up” the temperature, or, on the contrary, turn on extremely rarely. In some cases, the refrigerator may not turn on at all, although the light in the compartment is on. This indicates that thermostat contacts do not close.
- 🧊 A “snow coat” forms in the refrigerator compartment or ice freezes even at minimum settings.
- 🔇 Compressor is silent for a long time, while the chamber is warm, although there is light.
- 🔊 The unit works continuously, without going to rest, and the temperature inside drops below normal.
- ⚡ Frequent clicks of the relay when trying to start the compressor may indicate a problem in the control circuit.
It is also worth paying attention to the condition of the products. If vegetables wither too quickly or milk turns sour in one day, this is a sure signal that cooling cycle it is broken. In such cases, checking the thermostat becomes a priority for the owner.
Diagnostics and performance testing
Before you start replacing the part, you need to make sure it is faulty. The simplest method for diagnosing a mechanical regulator is visual inspection and “freezing”. To do this, disconnect the refrigerator from the network, defrost it and remove the thermostat. Then the sensitive tube is placed in a container with cold water and ice for several minutes.
After cooling, the tubes are checked with a multimeter in dial mode. If, when removing the tube from the cold, a click is heard and the device shows the presence of a circuit, then the regulator is working. The absence of a click or ringing indicates that the mechanism is jammed or the seal of the bellows is broken.
☑️ Thermostat diagnostics
For electronic models, diagnostics are more complicated and require checking the sensor resistance at different temperatures. Resistance values must correspond to the characteristics table for a specific model Indesit. A deviation from the norm, even by a few ohms, can lead to errors in the operation of the control board.
Table of faults
To systematize information about possible problems with the temperature controller, it is convenient to use a pivot table. It will help you quickly navigate the symptoms and choose the right algorithm of action. Remember that accurate diagnosis requires compliance with safety precautions.
| Symptom | Probable cause | Check method | Solution |
|---|---|---|---|
| The refrigerator does not turn on | Open circuit of the thermostat | Contact continuity | Replacing the regulator |
| Continuous operation of the motor | Sticking contacts or leaking freon | Metering temperature | Replacing the thermostat or refilling |
| Severe freezing | Incorrect calibration | Visual inspection | Adjustment or replacement |
| Frequent on/off | Sensor malfunction | Test with a multimeter | Replacing the sensor |
⚠️ Attention: When working with electrical components, always disconnect the device from the mains. Residual voltage can lead to electric shock or damage to the electronics.
Replacing the thermostat with your own hands
The process of replacing a mechanical thermostat in a refrigerator Indesit is technically simple, but requires care. After removing the decorative panels and removing the faulty part, you need to install a new regulator. The main condition is that the new element must have identical parameters, especially the length of the capillary tube and the temperature range of operation.
The installation of the sensitive tube must be done in the same location where the old one was fixed. It is important to ensure tight contact of the tube with the surface of the evaporator, since the accuracy of temperature reading depends on this. Often, special clamps or heat-conducting paste are used for fixation.
After assembling all the components and connecting the electrical part, the refrigerator is connected to the network. The first cycle of work may take several hours. At this time, it is not recommended to load the chamber with products in order to allow the unit to start working. normal mode work.
Setting and calibrating the temperature
Correct setting of the regulator is the key to long service life of the compressor and the safety of products. In mechanical models, the scale usually has numerical designations from 1 to 5 or 7. It is important to understand that the number does not indicate degrees, but the cooling intensity. The higher the number, the colder.
The optimal position of the control knob for most models Indesit is considered to be the average value (usually 3 or 4). In summer, when the ambient temperature is high, you can slightly increase the cooling. In winter, if the refrigerator is in an unheated room, the load should be reduced so that the compressor does not run idle.
In electronic models, adjustments are made using buttons on the display. Here you set specific degrees. The system itself will maintain the set parameter, turning on the compressor as needed. However, here too you should avoid extreme values unless necessary.
Is it possible to repair a thermostat without changing it?
Repairing a mechanical thermostat at home is practically impossible and impractical. Bellows leakage or spring wear require factory equipment for restoration. Electronic sensors are also not subject to repair and are replaced entirely.
Why does the refrigerator work longer after replacing the thermostat?
The new thermostat may have slightly different response characteristics. It also takes time for the compressor to stabilize the temperature after defrosting and installing new parts. If after 24 hours the mode has not returned to normal, check the tightness of the system.
Does the type of freon affect the operation of the regulator?
The type of refrigerant (R600a or R134a) does not directly affect the mechanics of the thermostat. However, different freons have different heat transfer efficiencies, which can indirectly affect the duration of the compressor operating cycles controlled by the regulator.