A sudden stop of the compressor or, conversely, its endless operation without stopping often indicates problems with the temperature control system. In refrigerators Atlant, which are famous for their reliability, the most vulnerable element in this unit is the thermostat. It is he who is responsible for turning the motor on and off depending on the temperature inside the chambers. If you notice that the food in the refrigerator has begun to deteriorate or, on the contrary, freeze, and the compressor is behaving strangely, the first thing to do is to diagnose the thermostat.
Independent testing of this component allows you to save a significant amount on calling a technician, since the procedure is quite simple and requires a minimal set of tools. However, it is important to understand that thermostat is an electrical device, and working with it requires compliance with basic safety rules. In this article, we will analyze in detail the algorithm of actions that will help you determine exactly whether the thermostat is to blame for the breakdown or whether the cause needs to be looked deeper.
Before you start disassembling, you need to know exactly where this element is located in your model Atlant. In most two-compartment refrigerators, it is located inside the refrigerator compartment, often hidden behind a plastic panel or directly in the lampshade. Single-chamber models may have an external thermostat, but modern versions of the brand more often use an internal installation. Your task is to carefully get to it without damaging the plastic latches of the case.
Symptoms of thermostat malfunction
The first sign of failure thermostat is a violation of the temperature regime. If the compressor does not turn on at all, and there is room temperature inside the chamber, this may mean that the contacts inside the thermostat have oxidized or broken, and the signal to start the engine simply does not arrive. In this case, the refrigerator is silent, but the light inside is on. The opposite situation, when the motor hums continuously without turning off for hours, also indicates sticking of the contacts in the “closed” position.
Another alarming symptom is cyclic operation at very short intervals. The compressor starts, runs for a couple of minutes and stops again. This indicates that it thermostat reads the temperature incorrectly or reacts too quickly to the slightest changes. In some cases, you can hear a characteristic click, after which the equipment should work, but this does not happen. If you hear a click, but the motor is silent, the problem may be not only in the thermostat, but also in the start relay or the compressor itself.
⚠️ Attention: If, when you try to turn on the refrigerator, you hear a humming noise, which ends abruptly after 5-10 seconds, and a click is heard, stop experimenting immediately. This may indicate a malfunction of the compressor or start relay, and further activation may permanently damage the unit.
Visual inspection can also provide clues. If the thermostat has visible signs of corrosion, melted plastic or damaged wire insulation, its replacement is necessary in any case. Sometimes the cause of problems is not the sensor itself, but its sensitive tube, which may have become dislodged or damaged. In models Atlant with electronic control, symptoms can be displayed on the display in the form of error codes, however, mechanical thermostats are silent and require manual checking.
Preparation for diagnostics and necessary tools
For a high-quality check of the thermostat, you will need a basic kit for a home technician. The main tool will be multimeter (or a tester) capable of measuring resistance and conducting a “continuity test” of the circuit. Without this device, diagnostics will be of a mere nature. You will also need a screwdriver (usually a Phillips or flat-head screwdriver, depending on the model of fastener) to remove the casing and the thermostat itself.
It would not be amiss to prepare a container with cold water and a thermometer if you plan to test using the immersion method, although testing the contacts is most often sufficient for initial diagnosis. Make sure you have good lighting, as the niche where the thermostat is located in refrigerators Atlantis often dark. Before starting any work, be sure to disconnect the refrigerator from the power supply - this is a critically important safety rule.
☑️ Preparing to check the thermostat
It is important to prepare the workplace. Place the tools on a stable surface. If you plan to remove the thermostat completely, have electrical tape or new terminals on hand in case the old ones turn out to be disposable or damaged during removal. In models Atlant KShD series or two-chamber refrigerators, access may be limited by the chamber wall, so be careful not to pierce the evaporator with the sharp edge of the tool.
Removing the thermostat in Atlant refrigerators
Removal process The thermostat in refrigerators Atlant has its own characteristics. In most models, the temperature control knob is simply removed by hand or pryed out with a flat screwdriver through a special hole. Under the handle you will see a plastic housing that is attached to the inner wall of the camera or to the lampshade. Carefully unscrew the fastening screws and remove the protective casing.
After removing the casing, you will see itself thermostat with the wires suitable for it. Refrigerators Atlant usually use two or three wires. One of them (often yellow-green) goes to ground the case; it can be immediately disconnected. The remaining wires (usually black, red or brown) are responsible for powering the compressor. Before disconnecting, it is strongly recommended to photograph or sketch the connection diagram so as not to mix up the contacts during assembly.
To remove the thermostat, you may need to remove the lampshade, since the device is often attached to it or behind it. A sensitive capillary tube that senses temperature is attached to the evaporator inside the chamber. It must be carefully snapped off from the mounting clips. Do not pull the tube sharply and with force - it is thin and easily breaks, which will lead to freon leakage from the sensor and its complete unusability.
Features of removing the sensor tube
The thermostat capillary tube in Atlant refrigerators can be fixed in a special channel of the evaporator or pressed with a bar. If the tube does not come out freely, do not force it. Inspect the mounting location - there may be a hidden fastener or a second screw there. Damage to the tube will cause the new thermostat to work incorrectly or not work at all.
When all fasteners are released, the thermostat can be removed from the niche. Be careful: the wires may be short, so proceed smoothly. If you are only planning a test, you don’t have to completely disconnect the wires, but only gain access to the contact group for connecting the multimeter probes. However, for full diagnostics and replacement, it is better to completely dismantle the assembly.
Methods of checking with a multimeter
The most reliable way to check thermostat is to use a multimeter in the resistance measurement mode (Ohm) or the "continuity" mode. If your tester has an audible short circuit indication mode, this will greatly simplify the task. First, move the regulator knob to an arbitrary position, for example, to the middle mark. Touch the probes of the multimeter to the contacts to which the wires from the network approached (usually these are the two main contacts).
If the multimeter shows a resistance close to zero or makes a sound signal, this means that the circuit is closed and current is passing through the thermostat. This is normal for the on position. Next, you need to check the thermostat's response to temperature. To do this, immerse the sensitive tube of the thermostat (only the metal part, without plastic and wires) in a container with cold water (temperature about 0...+2°C) for 2-3 minutes. After this, repeat the test.
In a working thermostat, when cooling, the contacts should open, and the multimeter should show infinite resistance (or remain silent if there is no sound mode). If, after immersion in cold water, the chain continues to ring, it means that the contacts are stuck or the mechanism is deformed, and the thermostat does not turn off the compressor when the temperature reaches a low temperature. In this case, it is required replacing the thermostat with a similar one in parameters.
| Contact state | Multimeter readings | Diagnosis | Actions |
|---|---|---|---|
| At room temperature temperature | 0 Ohm (Sound) | Normal (circuit closed) | Check reaction to cold |
| After cooling (0°C) | Infinity (No sound) | Normal (circuit open) | Thermostat is working |
| At any temperature | Infinity | Open circuit | Replacing the thermostat |
| After cooling (0°C) | 0 Ohm (Sound) | Sticking contacts | Replacing the thermostat |
There is also a test method bypass (jumper), but it requires caution. If you close the contacts of the thermostat directly and the refrigerator starts and freezes, then the problem is definitely in the thermostat. However, leaving the refrigerator to work with a jumper can only be done for a short time for diagnostics, since it will not turn off and may overcool the food or the compressor may fail.
Replacing and setting up a new thermostat
If the diagnostics confirmed a malfunction, you need to purchase a new one thermostat. For refrigerators Atlant it is important to select a part with similar markings or a complete functional analogue. The main parameters that you need to pay attention to are the length of the capillary tube, the on/off temperature and the presence of a third contact (for the indicator light or fan motor). Install the new thermostat in the reverse order.
Pay special attention to installing the capillary tube. It should be tightly secured in the same place where the original one was, usually on the last turn of the evaporator or in a special channel. The accuracy of the refrigerator's operation depends on the quality of contact between the tube and the cooled surface. If the tube hangs in the air, the thermostat will assume that the chamber is warm and the compressor will work without interruption.
After assembly and connection to the network, adjustment may be required. In some models Atlant there are adjusting screws under the seal on the thermostat body. It is not recommended to twist them without special equipment and knowledge, as you can reset the factory settings. Usually it is enough to simply set the knob to the average value and let the refrigerator return to mode during the day.
⚠️ Attention: Technical characteristics of thermostats may vary even within the same series of refrigerators. Before purchasing a new part, check the markings on the body of the old thermostat with the manufacturer's catalog. Using an unsuitable part can lead to incorrect operation of the refrigerator.
Common mistakes during self-repair
One of the most common mistakes is ignoring the condition of the contacts. Even if the thermostat rings, oxidized contacts can produce high contact resistance, which leads to heating and eventual failure. Always check the visual condition of the terminals. If they have black carbon deposits or traces of sparking, it is better to replace the entire assembly.
Another mistake is incorrect installation of the sensor tube. Amateur craftsmen often secure it with tape or tape where this is not provided for by the design. This disrupts heat exchange. The tube must be secured with standard clips or pressed tightly against the metal surface of the evaporator. In refrigerators Atlant with a No Frost system, the sensor may be located in the air duct, and its displacement will lead to errors in the operation of the defrosting system.
Don't forget about the wires. When reassembling, make sure that the wires are not pinched by the housing and do not touch moving parts or hot elements (although there is not much hot in the refrigerator compartment, the compressor heats up from below). Securely secure all connections so that the vibration of the compressor does not weaken the contact over time.
Is it possible to repair an old thermostat, or is it only necessary to replace it?
In 99% of cases, thermostats are non-separable devices. An attempt to disassemble the housing to clean the contacts usually leads to the seal of the bellows breaking and loss of sensitivity. Even if you manage to assemble it, it will be impossible to guarantee stable operation under conditions of temperature and humidity changes. Therefore, experts recommend only a complete replacement of the unit.
Why does the new thermostat click, but the refrigerator does not turn on?
The click means that the contacts are closed, but if the compressor is silent, the problem may be in the compressor itself, the start relay or the protective thermostat. It is also possible that when installing a new thermostat, you connected the wires incorrectly (mixed phase and neutral or ground). Check the connection diagram again.
How often do you need to change the thermostat in the Atlant refrigerator?
The service life of the thermostat usually coincides with the service life of the refrigerator itself (10-15 years). However, with frequent power surges in the network or mechanical damage (shocks during defrosting), it may fail earlier. Planned replacement is not required, they are replaced only in the event of a malfunction.