How to properly install the thermostat on a refrigerator

Failure of the temperature control system is one of the most common reasons why the refrigerator stops freezing normally or starts working without stopping. Thermoregulator (thermostat) is the main element responsible for maintaining a given microclimate inside the chambers. It is he who gives the command to the compressor to turn on when the temperature rises above normal, and turns off the unit when the required values are reached.

If you notice that the food in the main chamber has begun to deteriorate, and a “coat” of ice has formed on the walls of the freezer, or the motor is humming around the clock without rest breaks, most likely there is a problem. in the sensor. Independent replacing a thermostat is a completely solvable task for a person with basic skills in working with tools, but it requires attention to detail and strict adherence to safety precautions.

In this article we will analyze not only the mechanical installation process, but also the nuances of selecting compatible spare parts, calibration features and typical errors, which can lead to repeated failure. Properly performed repairs will extend the life of your refrigerator and save your budget, since the services of a technician often make up a significant part of the cost of a new part.

Diagnostics of the fault and selection of a new spare part

Before disassembling the refrigerator, you need to make sure that the culprit is It is the thermostat that is malfunctioning, and not, for example, a freon leak or a compressor failure. A classic sign of a malfunction is the absence of a click when turning the temperature control knob from the extreme position counterclockwise. In good condition, you should hear the characteristic sound of contacts opening. If there is no click, but the light bulb lights up when the door is opened, the circuit is most likely broken inside the thermostat itself. Another symptom is that the refrigerator does not turn off. The compressor is working hard, trying to reach a temperature that the sensor “does not feel” due to the contacts sticking in the closed position. In this case, replacement thermostat.

Another symptom is that the refrigerator does not turn off. The compressor is working hard, trying to reach a temperature that the sensor “does not feel” due to the contacts sticking in the closed position. In this case, replacement thermostat is inevitable. It is important to understand that different models of refrigerators require different types of sensors, which may differ in the length of the capillary tube, operating temperature range and mounting method.

⚠️ Attention: Before purchasing a new spare part, be sure to remove the old thermostat and rewrite its markings. Externally identical parts may have different temperature response ranges, which will lead to incorrect operation of the refrigerator after installation.

When choosing an analogue, pay attention to the length capillary tube. If it is too short, you will not be able to correctly place the sensitive element in the evaporator, and if it is too long, you will have to carefully roll it up, avoiding kinks and creases that could break the tightness of the system.

The necessary tools and preparation of the workplace

To successfully replace the thermostat, it is not required complex industrial equipment, but a set of tools should be on hand in advance so as not to interrupt the work process. The main tool will be a set of screwdrivers (Phillips and flathead) for dismantling control panels and the inner lining of the camera. You may also need a multimeter to check the continuity of the circuit and confirm the diagnosis before starting disassembly.

You will need good lighting, since many components are located in hard-to-reach places. Prepare a container to collect water if you need to defrost the evaporator during dismantling, and dry rags. Do not forget about gloves to protect your hands from sharp metal edges and possible contact with the refrigerant in case of damage to the tubes.

Pay special attention to safety. Although the thermostat operates at low voltage, the refrigerator itself is connected to a 220 Volt network. Any manipulations with electrical contacts should only be carried out with the device completely disconnected from the network. This is a critical requirementignoring which may result in electric shock.

Removing the old thermostat

The process of removing the old sensor begins by disconnecting the refrigerator from the power supply. Then you need to gain access to the thermostat installation location. In most modern models, it is hidden behind a plastic control panel or located inside the refrigerator compartment under the lampshade. Carefully remove all decorative plugs and unscrew the mounting screws using the appropriate screwdriver.

After removing the protective cover, you will see yourself thermostat with the wires coming to it and the capillary tube coming out. Before disconnecting the wires, it is strongly recommended to photograph the connection diagram or sketch it, so that when installing a new element you do not mix up the contacts. An error in the connection can lead to a short circuit or the compressor operating in the wrong mode.

Disconnect the wires from the terminals, having previously noted their location. Next, you need to remove the sensitive tube from the evaporator. It is usually inserted into a special socket or secured with a clamping bar. Proceed with caution: the tube is thin and breaks easily. If it is stuck or stuck, do not use excessive force, it is better to slightly warm the outlet with a hairdryer or defrost the chamber.

What to do if the capillary tube breaks?

If, when removing, the tube breaks inside the channel, do not try to remove the fragment with tweezers, you can pierce the wall of the evaporator. In this case, it is better to leave the fragment inside, carefully insulating the exit point, and when installing a new thermostat, use a tube of a new length, carefully placing its coil in an accessible part of the chamber.

Table of compatibility and parameters of thermostats

When selecting a spare part, it is important to focus not only on the external similarity, but also on the technical characteristics. Different manufacturers use different standards. Below is a table to help you navigate the main types of thermostats found in household refrigerators.

Using an inappropriate thermostat can result in the refrigerator either undercooling food or operating with overload. For example, installing a thermostat from the freezer into the main chamber will lead to deep freezing of the contents of the refrigerator compartment.

Installing and connecting a new thermostat

Installing a new one thermostat is done in the reverse order of dismantling. First of all, carefully insert the capillary tube into the mounting hole of the evaporator. The immersion depth should match the length of the tube on the old sensor or the manufacturer's recommendations. The sensing element must be in close contact with the surface of the evaporator to correctly read the temperature.

Fix the thermostat housing in place using screws or latches. Make sure it fits snugly and does not wobble, as vibration from the compressor can damage the contacts over time. Then connect the electrical wires to the terminals, strictly following the diagram or photograph you made earlier. If necessary, use new terminal clamps if the old ones are oxidized or deformed.

After connecting the electrics, assemble the plastic case, install all the decorative trims and return them to their place lamp shade. Make sure that not a single wire is pinched by a sharp edge of the metal or plastic of the case, which could lead to melting of the insulation in the future.

Calibration and performance testing

After assembly, the most important stage begins - testing and initial setup. Plug in the refrigerator and set the thermostat knob to the middle position. After 15-20 minutes you should hear a click when the compressor turns on. If the refrigerator starts working, let it reach its temperature. The operating time before the first shutdown can vary from 30 minutes to 2 hours, depending on the load and ambient temperature.

To accurately adjust the temperature inside the chamber, it is recommended to use an external thermometer placed in a glass of water. This will avoid errors associated with thermal expansion of air when opening the door. Adjust the position of the thermostat knob to achieve the desired readings: usually +3...+5°C for the refrigerator compartment.

⚠️ Attention: Do not make frequent and sharp turns of the thermostat knob during the adjustment process. The mechanism has a certain backlash and inertia, so changes in the operating mode will be noticeable only 20-30 minutes after each turn.

If the compressor does not turn on at all or, on the contrary, works without interruption even with the minimum position of the handle, an incompatible thermostat may be installed or an error was made when installing the capillary tube. In such cases, repeated diagnostics are required and, possibly, replacement of the part with a more suitable model.

Frequent errors during self-repair

One of the most A common mistake is incorrect positioning of the capillary tube. If it does not fit tightly to the evaporator or is located in an area where air circulation is impaired, the thermostat will “lie” by reading the wrong temperature. This leads to chaotic operation of the unit. Also, technicians often forget to check the integrity of the wire insulation, which can lead to a breakdown on the body.

Another mistake is ignoring the condition of the door seals during repairs. If the door does not close tightly, warm air enters the chamber, and no one, even the newest one, will be able to provide a normal temperature - the compressor will simply work for wear. Therefore, replacing the sensor should often be accompanied by checking and cleaning the sealing rubber. thermostat will not be able to provide a normal temperature - the compressor will simply work for wear. Therefore, replacing the sensor should often be accompanied by checking and cleaning the sealing rubber.

Some users try to “repair” the old thermostat by disassembling it and bending the contacts. This is strictly forbidden. The internal cavity of the sensor is filled with an inert gas or liquid under pressure, and a violation of the seal of the housing makes the part unsuitable for further use. Repair is only possible by completely replacing the unit.

Why can’t you twist the capillary tube into a ring?

Twisting the tube into a tight ring with a radius of less than 3-4 cm can lead to its kinking and blockage of the channel through which pressure is transmitted to the membrane. This will disable the new thermostat instantly.

Questions and answers about replacing the thermostat

Is it possible to install a universal thermostat on any refrigerator?

There are so-called universal thermostats with adjustable capillary length, but they are not suitable for all models. It is important to consider the operating temperature range and mounting method. For complex electronic control systems, a conventional mechanical thermostat will not work.

How can you tell if the thermostat is faulty without a multimeter?

A simple way is to short-circuit the wires going to the thermostat directly (temporarily). If the compressor starts when the circuit is closed, it means that the circuit is working, and the problem is in the sensor itself. However, this method requires caution and an understanding of the electrical circuit.

Is it necessary to defrost the refrigerator before replacing?

Yes, complete defrosting is required. Moisture can cause a short circuit in the contacts of the new thermostat or damage the insulation. In addition, ice can interfere with the correct removal and installation of the capillary tube.

Why does the new thermostat click, but the refrigerator does not freeze?

The click only means the electrical circuit is closed. If the compressor is humming, but there is no cold, the problem may be a freon leak or a malfunction of the compressor itself, and not the thermostat. The thermostat only gives the command to turn on.

How long does a new thermostat last?

The service life of a high-quality thermostat is on average 5-7 years of active use. However, with frequent power surges in the network or mechanical damage (shocks during transportation), this period may be reduced.