How to check the thermostat in an Indesit refrigerator: complete instructions

Has the refrigerator stopped turning off or, conversely, does not want to get cold at all? In most cases, the cause of unstable operation is the thermostat - a device responsible for maintaining the set temperature inside the chambers. In models Indesit this element often fails due to voltage surges or natural wear of contacts. Understanding the principle of its operation will help you diagnose the problem yourself and avoid an expensive call to a technician.

Before disassembling the unit, you need to make sure that the problem is the thermostat, and not a freon leak or a compressor malfunction. If the motor hums continuously, and the food in the freezer turns into an ice stone, or the chamber is warm, although the compressor is silent, these are the first bells. Thermostat is an electrical switch that opens the circuit when a certain temperature is reached. Checking it does not require deep knowledge in electronics, but requires attentiveness and compliance with safety precautions.

In this article we will analyze in detail the algorithm of actions for diagnosing mechanical thermostats that are installed in most refrigerators Indesit old and middle years of manufacture. You'll learn how to get to the part, what tools you'll need, and how to correctly interpret multimeter readings. Competent diagnostics will save you time and money, allowing you to accurately determine the need to replace a spare part.

Typical signs of a thermostat failure

Symptoms of a thermostat failure are often disguised as other problems. For example, if the refrigerator Indesit freezes too much, you may think that the capillary is clogged, although in fact the sensor contacts are simply stuck. And vice versa, when the chamber is warm, owners often blame the compressor, not suspecting that the control circuit is broken in the thermoregulation unit. The key sign is the nature of the motor’s operation: either it works without stopping, or it does not start at all, ignoring the turns of the regulator knob.

Pay attention to the condition of the products and condensation. If a huge coat of ice forms on the back wall of the refrigerator, and the vegetables in the drawers freeze, this is a direct signal that the sensor is not giving the shutdown command. If the thermostat does not close the contacts, the temperature in the chamber will rise, food will begin to spoil, and the compressor will be cold and quiet. Sometimes you can hear a characteristic click, which should occur when the position of the handle changes, but if it does not, the mechanism inside could be destroyed.

It is important to distinguish between mechanical and electronic control systems. In modern models with electronics (No Frost with a display), instead of a thermostat there are temperature sensors (thermistors), which are checked by resistance. However, classic ones Indesit are often equipped with mechanics. If your refrigerator makes strange sounds or operation cycles have become chaotic, it is worth checking the integrity of the wiring going to the control unit, since oxidation of contacts can also give false symptoms.

⚠️ Attention: Before starting any diagnostic work, be sure to disconnect the refrigerator from the power supply. Working with live electrical appliances is dangerous to life and can lead to a short circuit.

There are several indirect testing methods that do not require disassembly. Try to forcefully close the thermostat contacts (if you have access) or knock on it, sometimes this helps to temporarily restore contact if the problem is sticking. However, the most reliable way is to dismantle and check with a tester. You should not rely only on external signs, as they may also indicate problems with the start relay or the compressor itself.

Tools and preparation for diagnostics

To properly check the thermostat, you will need a minimum set of tools that any home mechanic can find. The main device will be a multimeter (tester) capable of measuring resistance and checking the integrity of the circuit (testing mode). Without this device, diagnostics will be just guesswork, since it is impossible to visually determine a break inside the sealed thermostat bulb. You will also need screwdrivers (Phillips and flathead) and possibly pliers.

Preparation of the workplace also plays an important role. Make sure there is good lighting, as the back of the refrigerator and the thermostat recess are often in the shade. You may need a flashlight. Prepare a container for defrosting in advance if you have to touch the defrosting system during dismantling, although complete defrosting is rarely required when replacing a thermostat. Have a dry cloth on hand for wiping contacts.

It is important to understand the design of your Indesit. In most models, the thermostat is located inside the refrigerator compartment, in a plastic box, or placed outside. The temperature control knob is usually located on the front panel or inside the chamber on the left. Before removing the handle, it is recommended to photograph the position of the marks in order to set the approximate operating mode after installing the new part.

Don't forget about safety. Although the 220V voltage is turned off, residual currents may remain in the circuit and the compressor capacitors may store charge. Use tools with insulated handles. If you find melted wiring or traces of burning, further operation without replacing the damaged areas cannot be carried out.

Removing the thermostat in Indesit refrigerators

The process of removing the thermostat in refrigerators Indesit is usually standard, but has its own nuances depending on the series. Most often, the thermostat is hidden behind a plastic cover inside the refrigerator compartment, next to the light bulb or adjustment knob. Some models require you to remove the top cover of the refrigerator. Carefully pry up the plastic plug with a flat-head screwdriver, being careful not to damage the latches, which become fragile over time.

After removing the decorative panel, you will see the thermostat itself - this is a metal or plastic box with a capillary pipeline (thin copper tube) and electrical wires coming out of it. The tube is usually inserted into a special socket in the evaporator or fixed to the wall. Capillary very thin and sensitive to damage, so it is strictly forbidden to pull on it. First you need to disconnect the electrical part.

The wires to the thermostat are approached through the terminal block or directly. Write down or take a photo of which wire is connected where. Color coding may vary and incorrect assembly will result in malfunction. Typically there are three wires: one goes to the compressor, one to the mains, and one (not always) can be a ground or indicator wire. Disconnect the terminals, if necessary, slightly heating them with a hairdryer if the plastic has turned sour.

The most delicate moment is removing the sensitive tube. It can be attached with a clip or simply inserted into the hole. In models Indesit there is often a screw fastening that presses the tube to the evaporator body. Unscrew it and carefully, with smooth movements, pull out the tube. If it is stuck, do not use force, it is better to drop a little warm water or use a hairdryer to defrost the ice.

What to do if the capillary tube breaks?

If during dismantling you damaged the thin copper tube of the thermostat, the device must be replaced. Repairing the capillary is impossible, since there is gas or liquid inside that ensures the operation of the mechanism. Buying a new thermostat is the only solution.

Checking the thermostat with a multimeter: step-by-step algorithm

The removed thermostat must be “ringed”. To do this, switch the multimeter to resistance measurement mode (Ohm) or audio testing mode. We apply the probes of the device to the contacts of the thermostat terminal block. In normal condition (at room temperature), the contacts of most thermostats Indesit should be closed, and the device will show zero or a value close to it, and also emit a sound signal.

For more accurate diagnostics, the thermostat must be placed in the cold. Place its sensitive tube in a glass of water and ice (temperature about 0°C) or put it in the freezer for 10-15 minutes. Once cooled, the contacts should open and the multimeter will show infinite resistance (one on the left of the screen). If the contacts do not open in the cold, then the thermostat is “stuck” and requires replacement.

Pay attention to the type of thermostat. There are normally closed (open when cooling) and normally open (close when heating, used in No Frost for defrosting). For the main refrigeration cycle normally closed ones are used. If the chain does not ring at room temperature, the thermal protection may have tripped or the mechanism is broken. Indesit Normally closed ones are used. If the chain does not ring at room temperature, the thermal protection may have tripped or the mechanism may be broken.

During the inspection process, inspect the case for swelling, traces of burning or corrosion. You can try to clean oxidized contacts with alcohol and an eraser, but if the problem is inside the sealed capsule, cleaning will not help. Mechanical wear of the bimetallic plate causes it to stop responding to changes in temperature.

Table: Symptoms and corresponding tester readings

To systematize the data received, use the following table. It will help you compare the behavior of your refrigerator with the measurement results. Remember that the readings may vary slightly depending on the specific thermostat model (for example, TAM-133, K-59 or analogs from Indesit).

This table covers the main scenarios. If you see that the resistance is jumping or showing strange values (for example, 50-100 Ohms), this may indicate burnt contacts or the presence of carbon deposits, which creates additional resistance. In the long term, it is better to replace such a thermostat. since heating at the point of poor contact can lead to a fire.

It is worth noting that there are two-pin and three-pin thermostats. In three-pin ones, one wire often goes to the compressor operation indicator light. When checking, it is important to find the power pair of contacts. Usually they are located at the edges or marked with numbers. If you are not sure, it is better to find a diagram of a specific model on the Internet or call all pairs. contacts.

Replacing and setting up a new thermostat

If diagnostics confirm a malfunction, the thermostat must be replaced. When purchasing a new part for Indesit pay attention not only to the length of the capillary tube (it may be longer than the original, the excess can be carefully twisted), but also to the temperature range of the installation. parameters of the regulator will lead to incorrect operation: either the refrigerator will not freeze or will freeze too much.

Installation is carried out in the reverse order. Carefully insert the sensitive tube into the hole until it stops, but without fanaticism. Connect the wires according to the photographs taken earlier. Make sure that the wires do not touch the moving parts, the compressor or the hot tubes of the condenser. plastic box and adjustment knob.

After assembly, turn on the refrigerator. The first cycle of operation may be longer than usual. Let the unit rise to temperature for 5-8 hours without loading food. Check if the compressor turns off when it gets cold. If the refrigerator turns off and turns on again when heating, you have completed the task successfully.

⚠️ Attention: Do not bend the capillary. the tube at an acute angle and do not twist it. This can lead to depressurization of the system and failure of the new part on the very first day.

The temperature is adjusted experimentally. Set the knob to the middle position. If the food in the refrigerator freezes after a day, reduce the power. If the milk turns sour quickly, add Optimal. the temperature in the main chamber should be +3...+5°C.

Frequently asked questions (FAQ)

Is it possible to temporarily close the thermostat to make the refrigerator work?

Yes, you can connect the wires directly, bypassing the thermostat. In this case, the compressor will work continuously until you unplug the refrigerator manually. This is an acceptable temporary measure to preserve food until you buy a new part, but you cannot operate the equipment this way for a long time - this will lead to freezing of the evaporator and overload. compressor.

Why does the new thermostat click, but the refrigerator does not turn on?

The click means that the thermostat mechanics are working. If the compressor is silent, the problem may be in the start relay, the compressor itself, or in the wiring between the thermostat and the motor. Also check whether the terminals are tightly seated on the contacts - they could have oxidized or. unclench.

Which thermostat is better to buy for Indesit: original or analogue?

Original spare parts Indesit (often manufactured Caparo or Ranco) are preferable, since their calibration exactly matches factory settings. Chinese analogues can work, but their response range is sometimes different, which will require more careful manual adjustment with the regulator knob.

Is it necessary to defrost the refrigerator before replacing the thermostat?

Complete defrosting is not necessary if you act quickly and carefully. However, if the thermostat tube is frozen into an ice coat. evaporator, you will have to either heat this area with a hairdryer, or defrost the chamber so as not to damage the capillary when removing it.

How to understand that the problem is not in the thermostat, but in a freon leak?

If the thermostat is working (ringing and opening), but the refrigerator does not freeze or freezes weakly, and the compressor is hot and works almost without stopping - most likely, there is a refrigerant leak. In this case, replacing the thermostat will not help; you need to call a technician to find the leak and refill it.