A sudden stop of the compressor or, conversely, its continuous hum is often the first sign that there is a failure in the temperature control system. Refrigerators of the Belarusian brand Atlant are famous for their reliability, but even time-tested models do not have an endless thermostat life. If you notice that the food in the chamber has begun to deteriorate, an excessive amount of ice has frozen, or the unit has simply stopped turning on, the problem may lie precisely in the thermostat.
Diagnostics of this unit is a completely solvable task for a home craftsman, which does not require complex industrial equipment other than a basic set of tools. Thermoregulator (or thermostat) is responsible for opening and closing the electrical circuit depending on the temperature inside the chamber. Understanding the principle of its operation will allow you to accurately determine whether an urgent replacement of a part is needed or a simple adjustment is sufficient.
In this article we will analyze in detail the algorithm for identifying faults, consider the design features of various models Atlant and provide clear instructions for safe measurements. Ignoring the symptoms of a breakdown can lead to failure of more expensive components, such as a compressor or evaporator, so the timely response of the owner is critical.
Principle of operation and signs of a thermostat malfunction
The thermostat is an electromechanical device that responds to changes in the temperature of the sensing element, located inside the chamber. When the temperature reaches a preset threshold, the contacts open and the compressor stops. As the temperature rises, the process is repeated in reverse order. Violation of this cycle indicates that control mechanism has stopped reading data or transmitting commands correctly.
There are a number of characteristic symptoms that indicate the need to check this particular element. Owners often confuse them with compressor problems or freon leaks, so it is important to conduct a thorough visual and technical inspection. Pay attention to the following manifestations:
- ❄️ The refrigerator compressor Atlant does not turn on at all, while the light inside is on and you can hear the quiet hum of the network.
- 🧊 The unit operates continuously without turning off, which leads to the formation “coats” of ice even in models with the No Frost system.
- 🌡️ The temperature in the main chamber differs significantly from that set on the regulator, despite the serviceability of other systems.
If you observe one of the listed signs, there is a high probability that contact group the circuit inside the thermostat itself is stuck or has an open circuit. It is also worth considering that in two-chamber models with one compressor, a malfunction of the thermostat can have different effects on the operation of the freezer and refrigeration chambers.
⚠️ Attention: Before starting any diagnostic work, be sure to disconnect the refrigerator from the power supply. Working with live electrical wiring is dangerous to life and can lead to a short circuit.
Preparation for diagnostics and the necessary tools
For a high-quality check of the temperature relay, you will need a minimum set of tools that most home craftsmen can find. The main requirement is the accuracy of the measuring instruments, since an error can lead to false conclusions. First of all, you will need multimeter (tester) to test the circuit.
The preparation process includes not only finding tools, but also providing access to the node. In refrigerators Atlant the thermostat is most often located inside the refrigerator compartment, under a plastic cover, or outside, depending on the model series. You may need:
- 🔧 A set of screwdrivers (phillips and flat) for removing decorative panels and dismantling the assembly.
- 🔌 Pliers or side cutters for carefully disconnecting the terminals if they are tight.
- 🧊 A container with cold water or ice to simulate working conditions (when checking without removal).
It is important to ensure good lighting of the work area, since it may be dark inside the chamber, and the markings of wires and contacts require careful study. If the refrigerator model requires complex disassembly, clear the space in front of the unit in advance for easy access.
☑️ Ready to check the thermostat
Removing the thermostat in Atlant refrigerators
The procedure for removing the thermostat may vary slightly depending on the specific series of the refrigerator Atlant. In most modern models, the regulator is hidden behind a plastic cover on the inner wall of the chamber, next to the light lamp or defrost button. First, you need to carefully remove the regulator handle by pulling it towards you.
After removing the handle and decorative trim, you will see the thermostat body itself, mounted on the wall. It is often secured with special latches or screws. Proceed carefully so as not to damage the fragile plastic, especially if the refrigerator has been in use for a long time and the material may have lost its elasticity. Capillary tubecoming from the body is very thin and is easily pinched, so you absolutely cannot pull on it.
When removing the unit, pay attention to the markings of the wires. Refrigerators Atlant usually use a standard color scheme, but it is best to photograph the location of the contacts or mark them with a marker before unplugging them. This will save you from errors during reassembly.
If the thermostat is located outside (found in older models), access to it is through the back panel or the top of the case. In this case, dismantling requires removing the compressor protective casing or the top cover of the refrigerator.
Features of the capillary tube
The capillary tube is filled with refrigerant (freon), which expands or contracts when the temperature changes. Any microcrack or bend in the tube will lead to failure of the thermostat, since the pressure inside the system will change and the contacts will no longer open.
Checking the thermostat with a multimeter
The most reliable way to determine the performance of a part is to test the contacts with a multimeter. To do this, switch the device to resistance measurement mode (Ohm) or continuity mode. If you have an analog tester, make sure that the arrow is at zero before starting measurements.
Connect the multimeter probes to the thermostat contacts. Under normal conditions at room temperature, the contacts should be closed and the device will show a resistance close to zero or emit a beep. If the screen displays one or infinity, it means that the circuit is broken and the part requires replacement.
For a more accurate diagnosis, you can conduct an experiment with changing the temperature. Place the sensitive part of the thermostat (the can) in a container of ice water for a few minutes. After cooling, the contacts should open and the multimeter will show no conductivity. If this does not happen, it means opening mechanism jammed.
The table below shows the main states of the contacts and their interpretation:
| Condition | Indications multimeter | Action |
|---|---|---|
| Normal (heat) | 0 Ohm (Sound) | Good |
| Open (heat) | ∞ (No sound) | Replacement |
| Normal (cold) | ∞ (No sound) | Good |
| Stuck (cold) | 0 Ohm (Sound) | Replacement |
Visual inspection and search for indirect defects
Even if the test shows normal results, do not rush to assemble the refrigerator. A careful visual inspection can reveal hidden problems that will manifest themselves in the near future. Inspect the thermostat housing for cracks, dents or signs of corrosion.
Pay special attention to the condition of the wire insulation and the points at which the capillary tube enters the housing. If you notice traces of oxidation on the contacts, they can be carefully cleaned, but it is better to replace the entire part, since oxidation often indicates moisture getting inside the mechanism. Tightness the unit is a key factor in durability.
Also check the tightness of the sensing element to the evaporator. In refrigerators Atlant the thermostat tube must be tightly fixed in a special groove or pressed with a plate. If contact with the evaporator is broken, the thermostat will “think” that the chamber is warmer than it actually is, and the compressor will work intermittently.
⚠️ Attention: Never try to bend or shorten the capillary tube of the thermostat. This will disrupt the calibration of the sensor, and the refrigerator will no longer maintain the temperature correctly.
Replacing and setting up a new regulator
If diagnostics confirm a malfunction, the only correct solution will be to install a new thermostat. When purchasing a new part, be sure to check the markings with the old one. For refrigerators Atlant thermostats of the TAM or K-59 series are often used, but their response parameters may differ.
Installation is carried out in the reverse order of dismantling. Carefully lay the capillary tube along the existing channels, avoiding kinks. Secure the housing in its original place and connect the wires according to the previously made marks or color scheme. After assembly, turn on the refrigerator and set the regulator to the middle position.
The first startup after replacement may take longer than usual. It will take time for the compressor to reach the required temperature and turn off at the signal of the new thermostat. Do not load the chamber with products in the first few hours of operation, let the unit return to operating mode.
In some cases, additional adjustment may be required with a screw located on the thermostat housing. However, the factory setting is usually optimal for most household conditions. It is worth interfering with calibration only if you have special equipment and an understanding of thermodynamic processes.
Is it possible to repair an old thermostat?
Theoretically, some types of faults (for example, oxidation of contacts) can be eliminated. However, practice shows that the seal of the case is broken after opening, and the accuracy of the settings is lost. The repair is temporary, so replacing with a new unit is more economically feasible and reliable.
Why does the Atlant refrigerator freeze weaker after replacing the thermostat?
This may be due to incorrect installation of the capillary tube (poor contact with the evaporator) or the use of a thermostat with other response parameters. It is also worth checking the amount of refrigerant in the system, since the problem can be complex.
How often should the thermostat be changed?
The average service life of a high-quality thermostat is 5-7 years of intensive use. However, with frequent power surges in the network or mechanical damage, it may fail earlier. Planned replacement is not required, only in the event of a malfunction.