Brand refrigerators Stinol have enjoyed well-deserved popularity for many years due to their reliability and simplicity of design. However, like any complex equipment, they require periodic maintenance or repair. One of the most common reasons why a unit stops maintaining the temperature correctly is a failure or incorrect operation of the thermostat. Understanding exactly how this unit functions will help the owner independently diagnose the problem and avoid calling a technician for simple operations.
The thermostat is an electromechanical device that controls the temperature conditions inside the chambers. It is he who sends a signal to the compressor to turn it on or off, ensuring cyclical operation of the refrigeration circuit. Models Stinol often use thermostats with a capillary tube, the operating principle of which is based on changing the volume of gas or liquid during heating and cooling. If you notice that the refrigerator works without interruptions or, on the contrary, turns off too often, the problem may lie in this component.
In this article we will analyze in detail the internal structure of the sensor, consider the algorithm of its interaction with the compressor and provide step-by-step instructions for checking the health of the device. Accurate diagnostics will allow you save time and money, since in many cases the fault can be identified without special equipment. We will also touch on issues of adjustment and replacement so that you can confidently carry out repair work.
The principle of operation and design of the thermostat
The basis of any mechanical thermostat installed in refrigerators Stinolis a sealed sensitive system. It consists of a capillary tube filled with freon or inert gas and a bellows (corrugated metal container). When the temperature inside the chamber changes, the working fluid in the tube expands or contracts, changing the pressure on the walls of the bellows. This mechanical movement is transmitted to the contacts, opening or closing the electrical power circuit of the compressor.
It is important to understand that Stinol thermostat is not just a switch, but a device that requires precise calibration. Inside the housing there is a spring mechanism that counteracts the pressure of the bellows. By adjusting the tension of this spring using the knob on the front panel, the user changes the temperature of the contacts. The tighter the spring is, the lower the temperature must drop so that the gas pressure in the capillary can open the contacts.
⚠️ Attention: The capillary tube of the thermostat is very thin and sensitive to mechanical damage. When replacing or installing the sensor, it is strictly forbidden to bend the tube at an acute angle or squeeze it with tools, as this will lead to depressurization and complete loss of sensitivity of the device.
The contact group inside the device is made of silver or special alloys that can withstand frequent cycles of switching on and off under load. Over time, carbon deposits can form on the contacts, which leads to sticking or, conversely, poor contact. In modern models Stinol there may also be electronic thermostats, where the role of the sensitive element is played by a thermistor that changes its resistance depending on the temperature, but classic mechanical models remain the most common in operation.
What is the difference between thermostats TAM, K-59 and other markings?
Thermostats are marked depending on the operating temperature range and type of mounting. For example, the TAM series is often used in single-compressor models, where one tube controls the main chamber, and the second (if any) controls the freezer. The K-59 label usually indicates a sensor for the main camera with a specific shutdown range. When replacing, it is important to select an analogue with an identical temperature range, otherwise the refrigerator will freeze too weakly or work for wear.
Symptoms of thermostat malfunction in Stinol refrigerators
You can determine that thermostat of the refrigerator Stinol it has failed by a number of characteristic signs that appear during the operating mode of the unit. The most obvious symptom is the compressor running continuously. If the motor hums for days without going into rest mode, and a “snow coat” or ice crust forms inside the chamber, this indicates that the thermostat contacts are closed and do not open when the set temperature is reached.
The opposite situation also indicates a breakdown: the refrigerator is silent and does not turn on, even if it becomes warm inside. In this case, the food begins to deteriorate, and room temperature is established in the chamber. This indicates that the circuit is broken and there is no signal to start the engine. Sometimes the malfunction manifests itself in the form of short operating cycles, when the compressor turns on for a couple of minutes, then turns off for a long time, without having time to cool the volume of the chamber.
- ❄️ Constant cold: The compressor does not turn off, a thick layer of ice grows on the back wall of the main chamber, the food in the refrigerator freezes.
- 🌡️ Lack of cold: The engine is silent, the light is on (if any), but there is no cold, even when the control knob is turned to the maximum position.
- ⚡ Chaotic operation: The unit turns on and off at irregular, too short intervals of time, which is accompanied by relay clicks.
It is worth noting that similar symptoms can occur if there is a freon leak or a faulty start relay. Therefore, before replacing the thermostat, it is necessary to exclude other causes. However, if, when the thermostat contacts are forced to close, the refrigerator begins to freeze normally and turns off, then the problem lies precisely in the sensor. Diagnostics with a multimeter in this case, it is the most reliable method of checking.
Diagnostics and checking the thermostat with a multimeter
To carry out high-quality diagnostics, you will need a regular digital multimeter set to the circuit continuity or resistance measurement mode. Before starting work, you must disconnect the refrigeratorunplug the plug from the socket. Access to the thermostat in different models Stinol may differ: in some cases you need to remove the top cover, in others you need to dismantle the lampshade or control panel.
After gaining access to the thermostat terminals, disconnect the wires from the contacts. Usually there are two or three. If there are three wires, then the third, as a rule, goes to the compressor operation indicator lamp. To check we need the main power contacts. Connect the multimeter probes to each other to make sure the device is working, and set the regulator knob to the middle position.
Attach the multimeter probes to the thermostat contacts. If the device shows "0" or makes a beep, the circuit is closed. This is normal at room temperature. Next, you need to check the circuit opens during cooling. To do this, the capillary tube (or the thermostat block itself, if it is removable) must be placed in a container with cold water or pressed against the frozen product. When the temperature drops, the contacts should open and the multimeter will stop beeping.
⚠️ Attention: Do not try to test a thermostat that is energized in resistance measurement mode - this may cause the multimeter fuses to burn out. Always make sure that the refrigerator is disconnected from the network before touching the contacts with the probes.
If the opening does not occur during cooling, or there is no contact already at room temperature, the thermostat is considered faulty and requires replacement. It is also worth visually inspecting the contacts for the presence of oxides or traces of carbon deposits that may interfere with the flow of current. In some cases, cleaning the contacts can temporarily restore functionality, but replacing with a new unit is a more reliable solution.
☑️ Algorithm for checking the thermostat
Do-it-yourself thermostat replacement: step-by-step instructions
Replacement process thermostat in the Stinol refrigerator requires accuracy and attentiveness, but is quite feasible at home. The first step is always to purchase a new regulator. It is important to choose a model with similar markings or a complete analogue that is suitable for the temperature range and capillary tube length. An incorrectly selected sensor will lead to incorrect operation of the refrigeration unit.
After disconnecting the refrigerator from the network and defrosting the chambers (if access to the evaporator is required), remove the old thermostat. Disconnect the wires after first remembering or photographing their connection diagram. Pay special attention to the fastening of the capillary tube: it can be secured with latches or clamps to the evaporator. Carefully release the tube, being careful not to damage it or touch the aluminum evaporator tubes.
Install the new thermostat in the reverse order of removal. The capillary tube must be fixed in the same place where the old one was located, ensuring tight contact with the surface of the evaporator for correct temperature reading. If the tube is longer than the old one, its excess can be carefully rolled into a ring, without bending, and placed in the free space behind the back wall of the chamber.
| Work stage | Required tools | Key points |
|---|---|---|
| Dismantling | Phillips screwdriver, pliers | Remember the wiring diagram |
| Removing the tube | No (by hand) | Do not pull the tube, release the fasteners |
| Installing a new | Screwdriver, electrical tape | Tight contact of the tube with the evaporator |
| Connection | Pliers | Reliable fixation terminals on the contacts |
After assembling all the components and connecting the wires, turn on the refrigerator. Initial entry into the mode can take from 2 to 6 hours. At this time, it is not recommended to open the doors frequently and load large quantities of food. Follow the cyclical operation: the compressor should turn on, cool the chamber to the set temperature and turn off.
Setting and calibrating the temperature mode
After replacing the thermostat or during operation, it may need to be adjusted. On the front panel of refrigerators Stinol there is usually a knob with numbers from 1 to 5 or 7. It is important to understand that these numbers do not indicate degrees Celsius, but indicate the intensity of cooling. Position "1" corresponds to the minimum cold (high temperature), and the maximum number corresponds to the most severe freezing.
For the main chamber, the optimal handle position is in the range 2-3. If you installed a new thermostat, it may take time for operation to stabilize. Some models provide the possibility accurate calibration using an adjusting screw located on the thermostat housing. Turning this screw changes the contact opening point, allowing you to shift the temperature range.
However, factory calibration is usually the most accurate. You should only interfere with the settings of the internal screw if you are confident in your actions and have an external thermometer to monitor the temperature inside the chamber. Shifting the adjustment even by half a turn can change the on/off temperature by several degrees, which is critical for the safety of food.
If, after replacing the thermostat, the refrigerator begins to freeze too much even at the minimum settings, or, conversely, does not reach the required values, the wrong type of sensor may be installed. In this case, it is necessary to check the markings and, if necessary, replace the device with a suitable one. You should not ignore inconsistencies, since constant operation in abnormal mode shortens the service life of the compressor.
Is it possible to repair an old thermostat, or is it better to replace it immediately?
Repairing a mechanical thermostat at home is practically impossible and impractical. The device is sealed, and violation of its integrity leads to loss of sensitivity. Even if it is possible to clean the burnt contacts, the service life of such a unit will be extremely short. Considering the relatively low cost of a new thermostat, replacement is the only reasonable solution.
Why does the Stinol refrigerator not turn off after replacing the thermostat?
There may be several reasons: the type of thermostat is incorrectly selected (wrong temperature range), the capillary tube does not fit tightly to the evaporator and does not feel real cold, or the problem is not in the sensor at all (for example, freon leak or compressor malfunction). It is also worth checking whether the wires are connected correctly.
How often should you change the thermostat in the refrigerator?
The service life of the thermostat is not strictly regulated and depends on operating conditions. On average, mechanical thermostats last 5-10 years or more. Replacement is required only if signs of a malfunction appear: refusal to turn on/off or incorrect temperature maintenance. Preventive replacement is not required.