Refrigerator stopped turning off or, on the contrary, stopped freezing, although the motor hums without interruption? In most cases, the culprit of these problems is thermostat, which ceases to correctly read the temperature inside the chamber. This small device is the “brain” of the cooling system, and its failure requires immediate intervention to avoid food spoilage or icing of the evaporator.
Many owners of household appliances Indesit, Atlant or Stinol are frightened by the prospect of disassembling the unit, considering this a task for professionals. However, if you have a basic set of tools and follow safety precautions, you can replace the part yourself, saving a significant amount on calling a technician. The main thing here is not to rush and clearly understand the design of your device.
Before you start disassembling, you need to make sure that the problem lies in the regulator, and not in a freon leak or a compressor malfunction. If the motor runs non-stop or does not start at all with a working starting relay, the probability of breakdown thermostat is more than 80%. Let's look at the diagnostic and dismantling process step by step.
Signs of a malfunctioning thermostat
Understanding the symptoms is half the success in repair. Thermostat responsible for opening and closing the electrical circuit depending on the temperature. When it breaks, the contacts may become stuck closed, causing the compressor to run continuously, or they may become permanently open, leaving the chamber warm. In the first case, you will notice that a “fur coat” is growing in the freezer compartment, and the food in the main chamber is freezing.
In the second case, the refrigerator simply stops cooling, although the light inside is on. Sometimes there is an option: the device works, but with a large error. You set the average value, and the temperature jumps from +2 to +10 degrees. This indicates that capillary tube has lost its tightness or has become deformed, and the gas inside it has stopped responding to changes in thermal conditions.
⚠️ Attention: If the thermostat housing is swollen or there is a burning smell coming from it, do not under any circumstances attempt to repair it - only a complete replacement will correct the situation safely.
It is also worth paying attention to the nature of the click. A working device makes a clear, loud click when switching modes. If the sound is dull or absent at all, the mechanism inside could have soured or collapsed over time. This is especially common in older models Biryusa i Minsk.
Necessary tools and preparation
To successfully complete the task, you do not need complex industrial equipment. A standard DIY kit is sufficient. Safety is key: before starting any work, the refrigerator must be disconnected from the power supply. Do not ignore this rule, since you will be working with conductive elements.
You will need the following tools:
- 🔧 Screwdrivers (Phillips and flat) for removing panels and terminals.
- 🔪 Knife or thin awl for carefully prying up plastic latches.
- 🔦 Flashlight for inspecting hard-to-reach places inside the camera.
- 🧤 Gloves to protect hands from sharp edges and possible oil.
It is important to prepare the work area. Move the refrigerator away from the wall to allow access to the rear if you need to remove the compressor guard for inspection. Find a container in advance to collect water if ice has formed inside the chamber, which will have to be defrosted before removing the sensor.
Don't forget to prepare a multimeter. This device will allow you to accurately check contacts the thermostat for conductivity and finally verify its malfunction before installing a new part. Without a tester, replacement can only be done at random.
Where the thermostat is located in different models
The location thermostat depends on the design of the refrigerator and the year of its manufacture. In modern models with the No Frost system, the sensor is often hidden behind decorative panels, while in older two-chamber refrigerators it can be brought out. Understanding the type of your unit will save you time searching.
Main placement options:
- 📍 Inside the refrigerator compartment: usually at the top right, under the plastic cover, where the light bulb is also located.
- 📍 Outside the case: typical for older models Atlant i ZIL, where the adjustment knob is located on the outer wall next to the door.
- 📍 In the foamed part: in some models Stinol i Indesit the capillary tube is built into the wall, and the regulator can only be removed by reaching it through the internal panel.
If you see the temperature control knob inside the chamber, then most likely the thermostat is located right under it. In models with electronic control, there may not be a mechanical thermostat at all - its function is performed by electronic sensor, which looks like a small “tablet” on a wire.
It is important to know that in two-compressor refrigerators there can be two thermostats: one for the refrigerator compartment and one for the freezer. In such cases, replacement requires care so as not to confuse the wires and the purpose of the parts.
Removing the thermostat: step-by-step instructions
The process of removing a part requires care, especially when working with plastic elements that become fragile over time. Start by completely defrosting the refrigerator if there is ice in the compartment. Then remove all shelves and drawers to provide free access to the work area.
Next follow the algorithm:
- Remove the temperature control knob. It may simply pull towards itself or have a hidden screw under a decorative plug.
- Carefully pry up the plastic trim (if there is one) with a flat-head screwdriver. Act without fanaticism so as not to break the latches.
- Unscrew the mounting screws holding the thermostat housing.
- Take a photo of the location of the wires before disconnecting them. This is a critical point for proper assembly.
- Disconnect the terminals and remove capillary tube from the seat in the evaporator.
☑️ Checklist before removal
Be careful when removing the capillary tube. It is very thin and bends easily. If the tube is damaged, the gas will escape and the new thermostat will immediately fail. In some models, the tube may be glued to the evaporator - in this case, it must be carefully separated by slightly heating the joint with a hairdryer (with caution!).
⚠️ Attention: Never bend the capillary tube at an acute angle and do not hit the sensitive bellows of the device.
Diagnostics and testing multimeter
Before throwing away the old regulator or installing a new one, it makes sense to carry out a final check. This will help ensure that you are replacing the part that has failed rather than looking for the problem elsewhere. To do this, you will need a multimeter in dial mode.
The test is carried out as follows:
- ❄️ Place the sensitive part of the thermostat (bellows) in a container with cold water (about +5°C) for several minutes.
- 🔌 Connect the multimeter probes to terminal contacts.
- 👂 Listen for a click: when the temperature changes, a characteristic sound should be heard, and the device readings should change from “open” to “conductivity.”
If during cooling and heating the contacts do not “ring” or ring constantly, regardless of the temperature, it means mechanism it is faulty. Also check the integrity of the wire insulation - cracks can lead to a short circuit to the housing.
What to do if you don’t have a multimeter at hand?
You can use a test lamp (a socket with a light bulb and two wires) connected to a 220V network. However, this is less safe and requires extreme caution. It is better to purchase an inexpensive digital tester.
It often happens that the contacts simply burn out. In this case, stripping can give a temporary effect, but it is better to make a complete replacement, since the resource of the mechanism has already been exhausted.
Comparison of types of thermostats
When buying a new part, it is important to understand that they are different. There are no universal solutions here: the thermostat from Liebherr will not fit Oscar without modifications. The main difference lies in the length of the capillary tube and the temperature range of operation.
| Parameter | Single-chamber refrigerators | Double-chamber (No Frost) | Industrial display cases |
|---|---|---|---|
| Tube length | 0.7 - 1.2 meters | 2.5 - 4.0 meters | Up to 6 meters |
| Contact type | Normal closed | Normally open/closed | Specific |
| Protection | Basic | Waterproof | Reinforced |
| Price | Low | Average | High |
When choosing, pay attention to the labeling. The numbers at the end of the code often indicate the temperature range. For example, marking TAM-133 will differ in characteristics from TAM-145. If you install the wrong regulator, the refrigerator will either not freeze or work with short cycles, which will kill the compressor.
It is also worth considering the manufacturer. Chinese analogues may cost less, but their resource is often inferior to the original Danfoss or K thermostat. Saving a couple of dollars can lead to repeated repairs in six months.
Installation of a new regulator and configuration
Installation is performed in the reverse order. Insert the capillary tube into the same hole where you removed the old one, being careful not to damage it. Secure the housing with screws and return the decorative trims. The most important thing is to connect the wires to the terminals correctly.
A photograph taken before disassembly will help you here. If there is no photo, look for the markings on the thermostat itself:
- 🔴 The red or pink wire is usually connected to the contact marked "3" or "L" (line).
- 🔵 The blue or white wire often goes to contact "4" or "N" (neutral/load).
- 🟡 The yellow-green wire is grounding, it cannot be confused with anything.
After assembly, plug in the refrigerator. Don't load products right away. Let the unit run idle for 2-3 hours to reach operating mode. During this time, listen to how often the motor turns on and off. The cycles must be uniform.
⚠️ Attention: If after replacing the compressor runs without stopping for more than 2 hours, immediately turn off the device. The wrong temperature range is probably selected or the tube is installed incorrectly.
Adjust the position of the temperature knob. In summer, the load can be reduced, in winter - increased. Monitor the condition of the products on the first day of operation.
Is it possible to replace the thermostat with a universal one?
Yes, there are universal models, for example, series TAM or K-59that are suitable for many brands. However, it is critical to select the correct length of capillary tube. If the tube is too long, it will have to be carefully twisted into a ring (without bending!) and hidden in free space. If it is short, the sensor will not reach the control zone, and the refrigerator will not turn off.
Why does the new thermostat not click?
The absence of a click may mean that the temperature inside the chamber has not yet reached the threshold value for switching. Try artificially cooling the bellows (for example, by applying an ice pack, but without freezing it). If there is still silence, it is possible that a new part is defective or an incorrect connection.
How long does the thermostat last?
The average service life of a high-quality thermostat is 5-7 years. However, with frequent power surges in the network or regular overloads of the refrigerator (loading hot products), the service life may be reduced to 2-3 years. Preventive replacement every 10 years will extend the life of the entire cooling system.
Is it dangerous to change this part yourself?
The main risk is electric shock if safety rules are not followed and damage to the capillary tube, which can lead to a refrigerant leak (if the tube system is touched). With careful operation and the power is turned off, the risk is minimal.