Failure of the temperature control system is one of the most common reasons why the refrigerator compartment ceases to perform its functions or, conversely, begins to freeze food to the point of stone. Understanding how the thermostat is attached to the refrigerator is necessary not only for professional craftsmen, but also for owners of equipment who want to carry out diagnostics or independent repairs. Thermostat It is the main control element that reads the temperature inside the chamber and sends a command to the compressor to turn on or off.
Structurally, this unit can be located in different places, which directly affects the method of its fixation. In modern models, there are both overhead options and units built into the control housing. Errors when dismantling or installing a new element often lead to damage to the capillary tube or loss of tightness, so it is important to study in advance the fastening features specifically for your model Indesit, Atlant or Beko.
In this article we will analyze in detail all existing methods of fixation, consider the tools necessary for the work, and point out the critical points, ignoring which can completely damage the equipment. You will learn why the length of the capillary matters and how to properly secure the sensor so that it reads the readings correctly.
⚠️ Attention: Before starting any work on replacing the thermostat, be sure to disconnect the refrigerator from the electrical network. Working with electrical wiring and internal components under voltage is deadly.
Main types of location and methods of fixation
The first thing the master faces when disassembling is determining the type of thermostat installation. The algorithm of actions depends on this. There are two main placement options: inside the refrigeration chamber and outside, in a special box or under the top cover. Mechanical thermostats most often they have an external capillary tube, which requires careful handling during installation.
If the thermostat is located inside the chamber, it is usually hidden behind a plastic cover or installed directly on the wall. Fastening can be done using screws, special latches, or simply fixed by tightly fitting into the socket. It is important to understand that the sensitive element (capillary) in such models is immersed directly in the cooled volume or attached to the evaporator.
In the case of an external location, which is typical for many models Stinol i Biryusa, the thermostat housing is hidden under the top panel of the refrigerator. Here it is attached to a metal base or plastic frame. It is accessible after removing the decorative cover, which often requires dismantling the door or upper part of the case.
Regardless of the location, the key element remains the method of fixing the tube itself. It should not dangle, but it should not be stretched like a string. Correct fastening ensures stable operation of the entire cooling system.
Tools and preparation for replacing the thermostat
Before you begin removing the old and installing a new regulator, you need to prepare a workplace and tools. Haste in this matter is the main enemy, since the capillary tube of the thermostat is very thin and easily damaged. To carry out a quality replacement, you will need a set of screwdrivers, pliers and, possibly, a multimeter for preliminary diagnostics.
Particular attention should be paid to the cleanliness of your hands and tools. Oil or dirt on the contacts can cause oxidation and poor connections in the future. It is also recommended to photograph the wire connection diagram in advance, since the color markings from different manufacturers (Danfoss, Tam, K59) may differ.
List of necessary tools and materials:
- 🔧 A set of screwdrivers (phillips and flat) for removing panels and fastening screws.
- 🔌 Multimeter for checking the integrity of contacts and the absence of a short circuit.
- 🧤 Dielectric gloves to protect hands and prevent grease from getting on parts.
- 📸 Smartphone for photographing the connection diagram before disconnecting the wires.
It is important to ensure good lighting of the working area zones. The insides of the refrigerator are often hidden in the shadows, and it is almost impossible to see small latches or wire markings in poor light. If you work in a garage or workshop, use a portable lamp.
☑️ Checking readiness for repair
Removing the old thermostat: step-by-step instructions
The process of removing a faulty element begins with gaining access to it. If the regulator is located inside the camera, it is usually sufficient to remove the plastic casing that hides the light bulb and regulator. In some models Liebherr or Bosch it may be necessary to remove the shelf or even the back wall of the chamber if the sensor is hidden deeply.
After removing the decorative elements, you will see the thermostat itself. It can be secured with one or two screws, or held on with plastic latches. Carefully unscrew the fastener. If the thermostat is tight, do not use excessive force - just rock it gently. A sharp jerk can damage the capillary tube, which will make further repairs impossible without replacing the entire assembly.
The next step is to disconnect the wires. The golden rule applies here: one disconnected, one marked. Use colored markers or stickers so as not to confuse phase, zero and grounding. Contact They can be oxidized, so they should be carefully cleaned before installing a new element, although most often they change the entire unit assembly.
The most delicate moment is removing the capillary tube from the seat. It passes through a seal or a special bushing. You need to pull it out slowly, without jerking, controlling every millimeter. If the tube is stuck or stuck, you can slightly heat the outlet with a hairdryer (at minimum temperature) to soften the plastic or ice.
⚠️ Attention: The capillary tube is filled with refrigerant under pressure. If the tube is damaged, gas will escape and the thermostat will stop working. Do not bend the tube at an angle of less than 45 degrees and do not use sharp objects to pick at the exit point.
What to do if the capillary tube breaks off at the base?
If the tube breaks off, but the bellows itself is intact, in some cases (only for experienced craftsmen) soldering or using a special repair kit is possible. However, for domestic conditions, it is safer to replace the entire thermostat, since the tightness of the system is broken and the sensor will show incorrect values.
Specifics of fastening the capillary tube
Fasting the capillary tube is not just a matter of “throwing it in and forgetting it.” The accuracy of temperature reading depends on how tightly and correctly it is fixed. The tube should have maximum contact with the cooled surface (evaporator) or chamber air, depending on the design.
In most models, the tube is secured using a special clamp or clip that presses it to the evaporator plate. Sometimes heat resistant tape or aluminum tape is used to improve heat transfer. It is unacceptable for the tube to hang in the air without touching any surfaces - in this case, the thermostat will respond with a long delay.
The length of the free part of the tube also matters. If it is too long, it cannot be twisted into tight rings. It is allowed to form loops with a diameter of at least 4-5 cm. The excess length is neatly placed in the provided channels or fixed with clamps along the walls so as not to damage it when installing the rear panel.
Comparison of types of capillary fastening:
| Type of fastening | Where used | Installation features | Risks |
|---|---|---|---|
| Clamp (clip) | Most models Atlant, Indesit | The tube is inserted into the groove and secured with a spring | Loss of spring elasticity, poor contact |
| Fitting in the hole | Models with a remote sensor | The tube passes through the sleeve in the chamber wall | Insulation damage from the edges of the hole |
| Fixation with tape | Old models, retro refrigerators | Wound with aluminum tape to the evaporator | Tape peeling off, contact oxidation |
When installing a new thermostat, make sure that the end of the capillary tube (sensitive element) is located in the same area as the old device. A displacement of even a few centimeters can cause the refrigerator to operate in the wrong mode.
Installing a new thermostat and checking operation
Installation of the new element is carried out in the reverse order. First, the capillary tube is carefully inserted to the required depth. It is important not to overdo it here: if you press the tube against the bottom of the channel with force, you can break through the thin wall of the bellows. Movements should be smooth and progressive.
After fixing the tube, the thermostat housing is attached. The screws are tightened evenly, without distortion. If the model provides for fastening with latches, wait for the characteristic click. Then the wires are connected according to the previously made diagram or color marking. The contacts should fit tightly, without play.
After assembling all the panels and returning the refrigerator to its original position, you can carry out the initial test. Connect the equipment to the network. The compressor should start within the first minutes of operation. If you hear a click, but the motor does not hum, the starting relay may be faulty or the new thermostat itself may be defective.
Temperature control is best done using an external thermometer placed in a glass of water in the center of the chamber. This will give more accurate results than built-in sensors, which may have inaccuracies. The normal operating cycle should be about 15-20 minutes of operation and 20-30 minutes of rest, depending on the load and ambient temperature.
⚠️ Attention: Technical characteristics of refrigerators may vary depending on the year of manufacture and the specific modification. The parameters indicated in the instructions are average. Always check the technical documentation (diagram) for your specific model, located on the sticker inside the case or in the product passport.
Frequent installation errors and their consequences
Even experienced technicians sometimes make mistakes that lead to repeated calls or equipment breakdown. One of the most common problems is incorrect seating depth of the capillary tube. If you insert it too deeply, it may rest against the heat exchanger and become deformed, and if it is too shallow, it will not feel the real temperature in the chamber.
Another common mistake is ignoring the condition of the seals. The rubber bushing through which the tube passes becomes dull and cracks over time. If you install a new thermostat in an old, cracked bushing, warm air will flow into the chamber. This will lead to the formation of ice and increased load on the compressor.
It is also worth mentioning the problem of “cold contact”. If the wires are connected carelessly or stripped too short, the plastic will heat up at the connection point. Over time, this will lead to melting of the insulation and short circuit. Always check the reliability of the connection by lightly pulling the wire after installation.
Typical errors and their symptoms:
- ❌ Twisting of the tube: Leads to the rupture of the capillary inside, the thermostat stops turning on the compressor.
- ❌ Lack of pressure: The tube does not is pressed against the evaporator, the refrigerator “does not see” that it has reached the temperature, and freezes endlessly.
- ❌ Incorrect calibration: If the adjusting screw inside the thermostat was knocked down during installation, the temperature range will shift (for example, instead of -5°C it will be -25°C).
Attention and following instructions will help you avoid these problems. Don't be afraid to double-check your work several times before final assembly. Remember that a refrigerator is a complex mechanism where all elements are interconnected.
Is it possible to use a thermostat from another model?
In emergency cases, it is possible to install an analogue if the mounting dimensions, capillary tube length and temperature range match. However, it is better to look for the original spare part number or its full analogue in the catalog to avoid problems with setup and durability.
Questions and answers (FAQ)
How to understand that the thermostat is faulty before removing it?
Main symptoms: the refrigerator does not turn off and runs continuously, forming ice crust; or the compressor does not start at all, although the light is on. There may also be no click when turning the knob.
Is it necessary to defrost the refrigerator before replacing?
Yes, complete defrosting (at least 24 hours) is required. This will remove ice from the channels through which the capillary tube passes, and avoid damage to it when removed. In addition, it is safer to work with dry components.
Is it possible to repair an old thermostat or just replace it?
Modern thermostats are considered disposable units. Their housing is sealed at the factory, and breaking the seal when attempting to repair will result in leakage of filler gas. Repair is not economically feasible and technically difficult, so a complete replacement is recommended.
Why does the new thermostat click but does not turn on the refrigerator?
The compressor starting relay or the motor-compressor itself may be faulty. The reason may also be oxidized contacts or broken wiring. It is worth checking the voltage at the input to the thermostat and at the output from it at the moment of the click.
Does the length of the capillary tube affect the operation?
Yes, critically. If the tube of the new thermostat is longer than the old one, the excess cannot be cut off or twisted too much. You need to carefully lay the excess length along the wall. If the tube is shorter, it may not reach the desired zone, and the sensor will not work correctly.