The refrigerator is one of the most important household appliances in the house, and its sudden breakdown can cause serious stress. When the compressor runs continuously or, conversely, stops starting, the first thing to suspect is a malfunction of the temperature control system. Often the cause of such symptoms is a failed thermostat, which stops correctly reading the temperature in the chamber. Thermostat Replacing this component in brand refrigerators is a completely solvable task for a person who has basic skills in handling tools. You don't have to call a professional if you are willing to act carefully and follow safety precautions. Understanding the principle of operation of the unit and strictly following the instructions will allow you to restore the functionality of the equipment in a relatively short time and save your budget. thermostat (thermostat), which stops correctly reading the temperature in the chamber.
Replacing this component in brand refrigerators Atlant - a task that is completely solvable for a person who has basic skills in handling tools. You don't have to call a professional if you are willing to act carefully and follow safety precautions. Understanding the operating principle of the unit and strictly following the instructions will allow you to restore the functionality of the equipment in a relatively short time and save your budget.
Before starting disassembly, you need to make sure that the problem lies precisely in the thermostat, and not in a freon leak or a compressor breakdown. If the motor hums constantly, and the food freezes, or the chambers are warm, although the motor is silent, then the likelihood of a malfunction of the temperature sensor is extremely high. In this article we will analyze in detail the process of diagnostics, selection of analogues and direct replacement of the element.
Principle of operation and symptoms of malfunction
Thermostat is a mechanical or electronic device that serves as a link between the user and the compressor. Its main task is to control the temperature inside the refrigerator or freezer. When the temperature rises above the set value, the contacts close, starting compressor. When the desired cold is reached, the circuit opens and the engine stops.
Models Atlant most often use capillary thermostats. They respond to changes in gas pressure inside a sensitive tube, which is attached to the evaporator. If this mechanism wears out, the contacts may “stick” in a closed or open state, which leads to emergency operation of the unit.
⚠️ Attention: If your refrigerator has stopped cooling, but the compressor is running non-stop, and there is no frost on the evaporator, there may be a refrigerant leak. In this case, replacing the thermostat will not help.
Understanding the symptoms will help you avoid unnecessary work. The main signs of thermostat failure include:
- 🧊 The compressor operates around the clock without interruption, causing severe hypothermia of the products.
- 🔇 The engine does not start at all, although the light is on and the relay clicks (provided that the start-protection relay is working properly).
- 🌡️ The temperature in the chambers is unstable, the food is either defrosted or covered with an ice crust.
- 🔌 The thermostat housing has visible damage or traces of oxidation of the contacts.
Preparation for repair and selection of tools
Before starting any work with electrical appliances Safety rules must be strictly followed. The first step should always be to completely disconnect the device from the electrical outlet. Unplug the socket and make sure that the refrigerator is easily accessible from all sides. To replace the thermostat in models Atlant you will need a minimum set of tools that most home craftsmen can find.
You will need a flathead and Phillips screwdriver to remove panels and dismantle fasteners. You may also need an open-end wrench (usually 7 or 8 mm) to loosen the nuts securing the lamp housing or thermostat. It would be a good idea to prepare a multimeter to check the integrity of the electrical circuit if you want to further diagnose the old element.
☑️ Tools for replacing the thermostat
It is important to ensure good lighting of the work area. The interior of the refrigerator is dark and the parts are arranged compactly. Using a flashlight or headlamp will help you avoid mistakes when disconnecting wires. It is also recommended to prepare a container for small parts so as not to lose the screws during disassembly.
Diagnostics of the thermostat with a multimeter
Before disassembling half of the refrigerator, it makes sense to carry out preliminary diagnostics. This will help to accurately confirm that the problem lies precisely in thermostat. To do this, you will need to remove the thermostat from the seat, but do not completely disconnect the wires from it yet, if the design allows you to reach with probes.
Switch the multimeter to the continuity mode (or resistance measurement). At room temperature, most refrigerator thermostats should have their contacts closed. If the meter shows infinite resistance, the circuit is open and the thermostat is faulty. However, if the contacts are open, try to cool the sensitive tube by applying something cold to it, or, conversely, warm it with your hands to check whether the circuit is closed.
⚠️ Attention: Never check the integrity of the circuit with a multimeter while the device is connected to a 220V network. This will lead to instant failure of the tester and can be life-threatening.
For a more accurate check, you can remove the thermostat completely. In models Atlant it is often mounted in a niche above the door or inside the lampshade. After dismantling the “lamb” and the protective casing, you will have access to the terminals. Ring the contacts in different positions of the adjustment knob. Lack of response to turning the handle will indicate mechanical destruction of the insides of the unit.
Removing the old thermostat in Atlant refrigerators
The process of removing the thermostat in refrigerators Atlant has its own characteristics, depending on the specific series. In most single-compressor models, the thermostat is located inside the refrigeration chamber, in the corner near the lampshade or in a special box. In two-compressor models, access can be through the back wall or top panel.
Let's consider the classic dismantling option for models with a lampshade inside the chamber. First you need to remove the top shelf of the refrigerator compartment to gain free access to the ceiling. Then carefully unscrew the screws holding the lampshade. Having removed the lampshade, you will see the thermostat mounted on the bracket.
Next you should proceed according to the following algorithm:
- Remove the temperature control knob (it is simply pulled together by hand).
- Unscrew the screw or nut that secures the thermostat housing.
- Carefully pull the thermostat housing out, keeping an eye on the sensitive capillary tube.
- Disconnect the electrical wires from the terminals, having previously memorized or photographed the connection diagram.
The most crucial moment is removing the sensitive tube from the evaporator. It can be secured with a bracket or simply inserted into the technological hole. In older models Atlant the tube is sometimes attached with tape or tape. Be careful not to damage the thin copper tube, as this may compromise the tightness of the system, although the thermostat itself will not be affected.
| Model Atlant | Thermostat location | Mounting type tubes | Difficulty of access |
|---|---|---|---|
| Atlant MXM 1700 | Inside the chamber, near the ceiling | Inserted into the evaporator hole | Low |
| Atlant MHM 1800 | Inside the chamber, in a niche | Fixed with a bracket | Medium |
| Atlant 4000 series | Behind the rear panel (No Frost) | Hidden in the channel | High |
| Atlant 6000 series | Inside, by the door | On a clip | Low |
Nuances of dismantling in No Frost models
In refrigerators with a No Frost system, the thermostat is often located behind the rear plastic panel inside the chamber. To gain access, you will need to remove all the shelves, unscrew the screws around the perimeter of the back wall and carefully unclip the plastic clips. Be careful, plastic becomes brittle in the cold.
Installation of a new thermostat and assembly
After successful dismantling of the faulty part, you need to install a new one thermostat. It is critically important to select an analogue with identical parameters. Thermostats differ in the length of the capillary tube, the temperature range of operation and the location of the contacts. Using an unsuitable spare part will lead to incorrect operation of the refrigerator.
When installing a new sensitive tube, make sure that it is immersed in the evaporator to the same depth as the old one. Usually this is 10-14 cm, but it is better to focus on the length of the removed tube. The excess length cannot be twisted into a tight spiral, as this can lead to its rupture during thermal expansion. Carefully lay the excess along the channel without bending it.
⚠️ Attention: When connecting the wires, make sure that the terminals are seated tightly. Poor contact will lead to sparking, heating and possible melting of the plastic, creating a risk of fire.
Assembly is carried out in the reverse order. Place the thermostat housing in place and secure it with the fixing screw. Put on the adjustment knob. If you removed the lampshade or decorative panels, return them to their places by tightening all fasteners. Check that the wires are not pinched between the body and the wall of the refrigerator.
Checking operation and setting the temperature
After completing the installation work, the refrigerator must be plugged in. Do not load the chambers with products immediately. Let the unit run idle for 2-3 hours. This will allow the system to reach the specified temperature regime and make sure that the cycles of turning the compressor on and off are correct.
During the first hours of operation, listen carefully to the sounds. You should hear characteristic clicks of the thermostat when starting and stopping the engine. If the compressor runs continuously for more than 40 minutes without stopping, the thermostat may not sense sufficient cooling, and you need to check the fit of the sensing tube.
For a final check, use the following methods:
- 👂 Listen to the frequency of the cycles: normally the refrigerator should rest for about 30-40% of the total operating time.
- 🌡️ Use an external thermometer by placing it in a glass of water in the center of the chamber to check the actual temperature.
- ❄️ Check for excessive ice formation on the back wall or food.
If the temperature stabilizes within +2...+4°C in the refrigerator compartment and -18°C in freezer, and the compressor works cyclically, the repair can be considered successful. Otherwise, you may need additional adjustment of the screw under the seal (if there is one) or re-checking the correct installation of the tube.
Is it possible to use a thermostat from another manufacturer?
Yes, you can, if the main technical characteristics match: the length of the capillary tube, the temperature response range, the type of contacts and the dimensions of the seat. Popular substitute brands for Atlant — TAM, K59, Ranco. However, it is better to look for the original spare part number or a complete analogue in the catalog.
What to do if the new thermostat clicks, but the refrigerator does not start?
If there is a click, but the compressor is silent, the problem may not be in the thermostat, but in the start-up relay, the compressor itself or the wiring. Also check if voltage is coming to the thermostat input. It is possible that the wire was broken during replacement or there was poor contact in the terminal.
Do you need to defrost the refrigerator before replacing?
Full defrosting is not necessary if you work quickly. However, if there is a lot of ice in the chamber, it may interfere with access to the fasteners. In any case, before starting work, be sure to disconnect the device from the network.