Sudden spoilage of food or, conversely, the formation of an ice crust on the walls of the chamber often indicates a failure in the temperature control system. If your refrigerator Atlant stops turning off or, on the contrary, does not start the compressor at all, the thermostat becomes the first suspect. This small but critically important unit is responsible for maintaining a given temperature regime by opening and closing the electrical circuit of the engine.
Self-diagnosis allows you to save time and money, since calling a technician for a simple check can cost more than the spare part itself. In this article we will look at how to check the refrigerator thermostat Atlant in various ways, including methods that do not require complex equipment. You will learn to distinguish the symptoms of a regulator breakdown from malfunctions of other components of the unit.
However, it is worth remembering that working with electrical appliances requires compliance with safety precautions. Before starting any manipulations with the electrical part Be sure to unplug the refrigerator. Ignoring this rule may result in electric shock or damage to the electronics of the device.
Principle of operation and symptoms of a malfunctioning thermostat
A thermostat is a mechanical or electronic device that responds to changes in temperature inside the refrigerator or freezer. Models Atlant most often use mechanical regulators with a bellows tube filled with freon. When heated, the gas expands and closes the contacts, starting the compressor, and when cooled, it contracts, opening the circuit. If this mechanism jams, the refrigerator operates in emergency mode.
You can understand that the problem lies in the thermostat by the characteristic signs. Users often notice that the unit hums continuously without stopping to rest. In other cases, the motor is completely silent, although the chamber is warm. These symptoms may indicate that the contacts inside the relay are either stuck in a closed state, or have oxidized and do not conduct current.
The main signs of a thermostat failure:
- ❄️ The refrigerator works non-stop, the temperature in the chamber drops below normal, food freezes.
- 🔥 The unit does not turn on at all, while the light inside is on, and the compressor is cold.
- 🌡️ The temperature in the chamber fluctuates greatly, not corresponding to the position of the regulator knob.
- 💧 Ice forms on the back wall of the refrigerator compartment or, conversely, it completely dry when the engine is running.
It is important to distinguish a thermostat malfunction from problems with the start relay or freon leak. If the compressor hums, but does not start and after a few seconds it clicks, most likely the problem is in the start relay or the motor itself. If the motor runs for hours without a break, this is a classic symptom of “sticking” contacts of the thermostat.
⚠️ Attention: If you notice that the body of the refrigerator is very hot, but the temperature inside does not drop, do not rush to change the thermostat. First, check the tightness of the door seals and the absence of refrigerant leakage.
Visual inspection and initial diagnostics without instruments
Before picking up a multimeter, you can carry out an initial diagnosis, which often allows you to identify the problem. To do this, you will need to remove the thermostat. In refrigerators Atlant it is usually located inside the refrigerator compartment under the lampshade or behind a plastic panel at the top. Carefully remove the regulator handle and unscrew the fastening screws.
After removing the device, carefully inspect its body and bellows tube. Mechanical damage such as cracks, dents or corrosion on the tube may indicate a fill gas leak. If the gas is gone, the thermostat will physically not be able to respond to temperature changes, and the contacts will remain open.
It is also worth checking the condition of the electrical contacts. If they show black residue or oxidation, this may be the cause of a poor connection. In some cases, it is enough to clean the contacts with fine sandpaper to get the device working again. However, if the carbon deposits are too strong, it is better to replace the entire assembly.
One of the simple ways to check is the “freezing” method. Place the removed thermostat (without the bellows tube, if possible, or carefully bending it) in the freezer for 30-40 minutes. After this, quickly ring the contacts with the tester. If they do not close in the cold, then the device is faulty.
Checking the thermostat with a multimeter: step-by-step instructions
The most accurate diagnostic method is to check the resistance with a multimeter. This method allows you to say with confidence whether the electrical part of the thermostat is working. To carry out the procedure, you will need to switch the device to the resistance (Ohm) or continuity measurement mode.
First you need to gain access to the thermostat contacts. Remove the plastic plugs and disconnect the wires, after remembering or photographing their location. Models Atlant usually use two or three wires. If there are three wires, then one of them goes to ground the case; it can be ignored when checking the compressor circuit.
Connect the multimeter probes to the two main contacts of the thermostat. At room temperature, the contacts should be closed, and the device will show zero or a resistance value close to it. If the screen displays one or infinity, the circuit is broken and the thermostat requires replacement.
☑️ Check with a multimeter
Next you need to check the circuit opens. To do this, heat the thermostat body (you can hold it in your hands or put it in warm water, avoiding getting moisture on the contacts). When heated, the contacts should open and the multimeter will show an open circuit. If this does not happen, then the mechanism is jammed.
The table below will help you interpret the instrument readings for different thermostat states:
| Thermostat condition | Ambient temperature | Multimeter readings | Diagnosis |
|---|---|---|---|
| Normal operation | Room (+20°C) | 0 Ohm (circuit closed) | Good |
| Normal operation | Heating (+40°C and above) | ∞ (circuit broken) | Good |
| Fault | Room | ∞ (circuit open) | Breakage of contacts |
| Fault | Heating | 0 Ohm (circuit closed) | Sticking contacts |
⚠️ Attention: When working with a multimeter, make sure that your hands are dry and the probes do not touch each other during measurement, so as not to get false readings.
Diagnostics of electronic thermostats in Atlant models
Modern models refrigerators Atlant, especially series with digital control, are equipped with electronic thermostats. In them, the role of the sensitive element is performed by a thermistor (temperature sensor), and not by a bellows tube. Testing such devices has its own characteristics and requires an understanding of the operating principles of electronics.
The electronic sensor changes its resistance depending on the temperature. A multimeter is also used to check it, but the resistance values will differ from mechanical analogues. Typically at room temperature the resistance is several kiloohms. The exact values for your model can be found in the technical documentation.
The testing process is similar: we measure the resistance at room temperature, then cool the sensor (for example, by putting it in the freezer) and measure again. The resistance should change smoothly. If the device shows a break or the value does not change, the sensor is faulty.
Features of electronic sensors
In electronic control systems, it is often not the sensor itself that fails, but the contacts in the connector connecting to the control board that oxidize. Before replacing the sensor, try cleaning the connector with alcohol.
It is worth noting that in electronic systems, a failure can be caused not only by a breakdown of the sensor, but also by a malfunction of the control board. If replacing the thermistor does not help, perhaps the problem lies deeper, and professional electronics diagnostics will be required.
Replacing the thermostat: algorithm of actions and nuances
If the diagnostics confirmed a malfunction of the thermostat, it must be replaced. For refrigerators Atlant it is important to choose an analogue with identical parameters, especially the length of the bellows tube and the temperature range of operation. Using an unsuitable spare part can lead to incorrect operation of the unit.
Installation of a new thermostat is carried out in the reverse order of dismantling. Carefully insert the bellows tube into the mounting hole, being careful not to damage it or bend it. Secure the regulator body with screws and connect the wires according to the diagram or photograph made earlier.
After assembly, turn on the refrigerator and set the regulator handle to the middle position. During the first hours of operation, monitor the temperature in the chamber. If the refrigerator begins to freeze too much or, conversely, does not gain cold, additional adjustments or replacement of the spare part with a more suitable one may be required.
Do not forget that after replacing the thermostat, the refrigerator may take time to come out to operating mode. Do not load the chamber with products during the first 4-6 hours of operation; let the device reach temperature while empty.
Frequent errors in diagnostics and maintenance
When doing self-repair, users often make mistakes that can aggravate the situation. One of the most common is an attempt to adjust the thermostat without first checking its serviceability. Tightening the adjustment screws on a faulty device will not produce results and may throw off the factory calibrations.
Another mistake is ignoring the condition of the door seals. If the door does not fit tightly, warm air enters the chamber and the refrigerator operates continuously. In this case, replacing the thermostat will not solve the problem, since it will respond properly to a real increase in temperature.
It is also worth mentioning the error when choosing a spare part. Thermostats for different models Atlant may differ not only in the length of the tube, but also in the on/off temperature. Installing a regulator from another model may result in the refrigerator either not freezing or overfreezing food.
⚠️ Attention: If you are not confident in your abilities or are afraid of damaging the cooling system, it is better to contact a specialized service center. Inept actions can lead to freon leakage.
FAQ: Frequently asked questions
Is it possible to temporarily bypass the thermostat to make the refrigerator work?
Technically, you can short the wires directly and the compressor will earn. However, in this mode the refrigerator will run continuously, resulting in deep-frozen food and possible damage to the compressor due to lack of rest cycles. This solution is only permissible for a short time to save food before the technician arrives.
How often do you need to change the thermostat in the Atlant refrigerator?
The service life of a mechanical thermostat is on average 5-7 years, but with intensive use or power surges it may fail earlier. Electronic sensors usually last longer, but are more sensitive to moisture.
Why does the refrigerator not turn off after replacing the thermostat?
This may be due to incorrect installation of the bellows tube (it does not fit tightly to the evaporator), the use of the wrong thermostat model, or a freon leak. It is also worth checking whether the start relay is jammed.
Where is the thermostat located in a two-chamber Atlant refrigerator?
In most two-chamber models Atlant the thermostat is located in the refrigerator compartment. It can be hidden under a lampshade or behind a decorative panel at the top of the chamber. In some models, access to it is through the top cover of the refrigerator.