Failure of the thermostat in refrigerator Atlant often leads to serious malfunctions in the operation of the compressor: either it stops starting at all, or it works without stopping, freezing food to the point of stone. This small device is the “brain” of the cooling system, monitoring the temperature inside the chamber and sending a command to turn the motor on or off. If you notice that the refrigeration chamber is too warm or, conversely, everything is covered with ice, and the compressor behaves inadequately, most likely, diagnostics or replacement of the thermostat.
The replacement process does not require deep engineering knowledge, but does imply compliance with safety precautions and strict adherence to the wiring diagram wires An error in connecting the contacts can lead to a short circuit or failure of the compressor, so each step must be treated carefully. In this article we will analyze all the nuances of installing a new sensor, typical errors and ways to check the functionality of the system.
Before starting disassembly, you need to turn off the power to the device and prepare the tool. You will need a flathead and Phillips screwdriver, pliers and preferably a multimeter to test the circuits. Remember that any work inside the electrical appliance is only permissible when the power is completely disconnected from the mains.
⚠️ Attention: Before starting any work to replace the electrical components of the refrigerator, be sure to disconnect it from the electrical network. Working under voltage is deadly and can lead to electric shock.
Diagnostics of thermostat malfunction
Before disassembling the refrigerator, you should make sure that the problem lies in the thermostat, and not in a freon leak or compressor failure. The main sign of a sensor malfunction is the absence of a characteristic click when turning the temperature control knob. If you turn the knob from minimum to maximum, and silence remains, this is the first bell.
Another symptom may be the operation of the motor-compressor in continuous mode. In normal condition cooling cycle intermittent: the refrigerator gets cold, turns off, the temperature rises, and it turns on again. If the unit hums for days on end, and a “snowdrift” forms inside, it means that the thermostat does not give the command to stop the engine.
For final confidence, you can carry out a simple test. With the refrigerator running, carefully remove the thermostat (without disconnecting the wires) and lower its sensitive tube into a container of warm water. If after a few minutes you do not hear a click of the contacts opening, the part is faulty and requires replacement.
Removing the old thermostat
In refrigerators Atlant the thermostat is most often located inside the refrigerator compartment. Access to it can be hidden behind a plastic cover of the lighting lamp or a special decorative overlay in the corner of the chamber. In some models, especially two-chamber ones, it may be located outside, under the top cover of the case.
The extraction process begins by removing the regulator handle. She just pulls herself, sometimes with a little effort. After this, the screw securing the device body is unscrewed. Be careful: the capillary tube coming from the sensor is very thin and is easily damaged if handled carelessly.
- 🔧 Remove the plastic cover or shade that hides the thermostat by unscrewing the fastening screws.
- ❄️ Carefully pull the sensitive tube out of the evaporator, being careful not to bend it at a right angle.
- 🔌 Fix the position of the wires before disconnecting, so as not to confuse them during assembly.
When the housing mounting screws are unscrewed, lightly pull the device towards you. You will see a terminal block with wires connected. This is where maximum concentration is required. Before disconnecting, it is strongly recommended to photograph the connection diagram or sketch it, since the color marking of the wires in different models Atlant may differ.
☑️ Preparation for dismantling
Connection diagram and wire color
Most The critical stage is the correct connection of the new thermostat. The standard circuit for refrigerators Atlant usually involves three or four wires, each of which is responsible for its own function. An error in connecting even one wire can lead to the fact that the refrigerator will not start or will not work correctly.
Consider the classic color coding, which is found in most models. However, always check the technical documentation for the specific model of your device, as manufacturers may make changes to the design.
| Wire color | Function | Where it is connected |
|---|---|---|
| Red | Phase (power supply) | Contacts 3-4 (input) |
| Orange | Compressor start | Contact 3 (compressor output) |
| Black | Lighting lamp | Pin 4 (lamp output) |
| Yellow-green | Grounding | Case or grounding terminal |
If you install a universal analog instead of the original sensor, the numbering of the contacts may not match. In such cases, it is necessary to use a multimeter in dialing mode. At room temperature, the contacts should ring in a certain position of the handle, and when cooled (for example, if you press the tube against something cold), they should open.
⚠️ Attention: Never connect wires by twisting without subsequent soldering or using high-quality terminal blocks. Poor contact will lead to heating, melting of the insulation and possible fire.
What to do if the colors of the wires do not match?
If the colors of the wires on the new thermostat differ from the old ones, do not rely only on the color. Use a multimeter to look for pairs of contacts that close when you turn the knob. Typically this is the input phase and output to the compressor. The wire of the lighting lamp is connected to a contact that opens when the light is on (depending on the design).
Installation and fastening of the sensitive tube
After the electrical connection, it is necessary to correctly install the sensitive element - the capillary tube. It is she who reads the temperature inside the chamber. If the tube is not secured correctly, the refrigerator will “lie” about the temperature, which will lead to food spoilage or icing.
In refrigerators Atlant the tube is usually inserted into a special hole in the evaporator or pressed against its back wall with a metal strip. The immersion depth should be the same as the old sensor. Usually this is 10-15 centimeters, but it is better to measure the length of the working part of the old thermostat.
Do not allow the tube to be kinked. A sharp break in the capillary will disrupt the circulation of the refrigerant inside the sensor, and it will stop responding to temperature changes. Also avoid contact of the tube with other metal parts, except for the mounting area, to avoid false readings.
- 📏 Measure the length of the immersion part of the old sensor to accurately install the new one.
- 🧊 Make sure that the end of the tube is pressed tightly against the surface of the evaporator for heat exchange.
- 🚫 Avoid contact of the sensitive element with the plastic parts of the camera body.
Attachment is carried out using a standard clamp or a special bracket. If the old clamp breaks, you can use a heat-resistant clamp, but be careful not to squeeze the tube. Reliable fixation is the key to stable operation of the entire system.
Setting and calibrating the temperature
After assembling the refrigerator and connecting it to the network, the setup stage begins. Don't expect instant results: the refrigerator needs time (usually from 2 to 6 hours) to reach operating mode and stabilize the temperature at all points in the chamber.
The thermostat knob should initially be set to the middle position. In refrigerators Atlant this is usually a division “3” or “4”. If after several hours of operation the temperature turns out to be insufficient, you can gradually increase the power by turning the knob clockwise.
It is important to understand that thermostats have a factory calibration, but it may “float” a little. If you notice that food begins to freeze even on the minimum settings, a mechanical adjustment may be required. On some models there is an adjustment screw under the handle, the rotation of which changes the temperature range.
If the compressor starts to turn on and off (short cycle), this may indicate that the new sensor is set too tightly or is faulty. In this case, try reducing the temperature a little or checking the tightness of the capillary tube.
Typical installation errors
Even experienced craftsmen sometimes make mistakes that negate all the work. One of the most common is incorrect capillary tube length. If it is too long, it is often rolled into a ring. This must be done extremely carefully, without creases, and the coils must be positioned so that they do not touch each other or other elements.
Another common mistake is ignoring the condition of the door seal. If you change the thermostat because the refrigerator won't keep cold, but the door rubber is worn out, the new sensor will be under constant stress trying to compensate for the loss of cold. This will lead to its rapid wear.
Also, users often forget to check the voltage in the network. Unstable voltage can simulate a broken thermostat, causing the compressor to turn on randomly. Before replacing expensive parts, make sure that everything is in order with the wiring in the house.
⚠️ Attention: Do not use thermostats from other refrigerator models without checking the parameters. Different models may have a different on/off temperature range and capillary tube length, which will lead to incorrect operation.
Checking operation after replacement
The final stage is a control launch. After connecting all the wires and installing the case in place, turn on the refrigerator. Pay attention to the sound: the start of the compressor should be accompanied by a characteristic hum, and after a while a shutdown click should follow (when the temperature is reached).
Check the operation of the lighting lamp. Open the door and the light should come on, close it and it should go out. If the lamp does not work, check the connection of the black wire (in the standard circuit Atlant). If the compressor does not start, double-check the connection diagram of contacts 3 and 4.
During the first 24 hours, refrain from loading a large amount of products. Let the unit idle to make sure the cycles are stable and there is no extraneous noise. If everything works properly, then repair of the thermostat it was completed successfully.
Is it possible to use a thermostat from another manufacturer?
Yes, you can use universal analogues (for example, TAM-133, K-59) if they are suitable for dimensions and length of the capillary tube. The main thing is compliance with the temperature range and type of contacts (normally closed/open).
Why does the refrigerator not turn off after replacing the thermostat?
Possible reasons: the wires are connected incorrectly, the capillary tube is not pressed tightly to the evaporator, there is a freon leak in the system, or the new thermostat itself is faulty (stuck contacts).
How to determine which wire is responsible for what without a diagram?
Use a multimeter. Ring the contacts: the wire coming from the network (phase) will ring with the wire to the compressor in one position of the handle and open in another. The third wire usually goes to the lamp.
Is it necessary to defrost the refrigerator before replacing?
Yes, complete defrosting is required. This will allow you to work safely with electricians, avoid water getting on the contacts and make it easier to remove the sensitive tube from the icy evaporator.