A decrease in cooling efficiency or a complete stop of the refrigerator often indicates a malfunction of the temperature control system. Equipment owners Indesit face similar problems regularly, especially if the unit is more than 7-10 years old. Thermoregulator is a key element that sends a signal to the compressor to turn on or off depending on the sensor readings.
If you notice, that the products began to deteriorate faster than usual, and ice appeared on the walls of the chamber or, conversely, room temperature reigns, most likely, this particular unit has failed. Replacing the thermostat is one of the most common procedures in the list of services for repairing household appliances. However, if you have basic skills in working with tools, you can perform this operation yourself, saving a significant amount.
In this article we will analyze in detail the algorithm of actions necessary to safely replace the temperature controller on brand refrigerators Indesit. We will look at the nuances of diagnostics, features of dismantling various types of thermostats and critical points when connecting a new device. Correct installation guarantees long and stable operation of your refrigerator.
Diagnostics of thermostat malfunction
Before you start purchasing a new spare part and disassembling the unit, you need to make sure that the diagnosis is correct. Often, symptoms indicating a breakdown of the thermostat can be caused by other reasons, for example, a freon leak or a compressor malfunction. Thermostat is an electrical switch that opens the compressor power circuit when the set temperature is reached.
The first sign of a malfunction is the continuous operation of the motor without stopping. If the refrigerator hums around the clock, and the temperature inside does not drop below +10°C, this is a direct signal that the sensor “does not see” the cold and does not give the command to turn off. In the opposite situation, the compressor may not start at all, even if the chamber is warm.
⚠️ Attention: Before starting any diagnostics, be sure to disconnect the refrigerator from the power supply. Working with electrical appliances under voltage is dangerous to life and health.
For a more accurate check, you can use a multimeter in dial mode. However, there is also a visual method for assessing the condition. If the regulator is mechanical, try gently turning the adjustment knob. The absence of characteristic clicks when moving through extreme positions may indicate mechanical jamming or breakage of the sensitive element.
Necessary tools and preparation
The success of the operation to replace the regulator largely depends on proper preparation of the workplace and the availability of the right tool. You do not need complex specialized equipment, but the set should be complete so as not to interrupt the process of searching for a screwdriver at the most crucial moment. The main tool will be a Phillips screwdriver, since most fasteners in refrigerators Indesit are made specifically for this slot.
You will also need a flat-head screwdriver to carefully pry up plastic latches and remove decorative panels. It would be a good idea to have a knife or scalpel on hand to clean the contacts if oxidation is detected on them. To work with wires, you may need electrical tape or heat shrink tubing, although ideally the connections should be airtight.
☑️ Preparing to replace the thermostat
It is important to ensure good lighting of the work area. The inside of the refrigerator compartment, especially the top part where the thermostat is usually located, is often in the shade. Using a headlamp or an additional lamp will greatly simplify working with small parts and wires.
Removing the old temperature controller
The process of removing the old device depends on the type of your refrigerator Indesit. In models with a weeping defrosting system, the thermostat is most often located inside the refrigerator compartment, under a plastic cover or directly mounted into the wall. In systems No Frost access to it may be limited by the evaporator or protective panels.
First you need to remove the temperature control knob. It can simply be removed by hand or can be secured with a locking screw that needs to be unscrewed. After this, access to the fastening elements of the thermostat housing itself opens. Carefully unscrew the screws and remove the device, being careful not to damage the capillary tube if it is brought out.
Pay special attention to the sensitive element - the capillary tube with the cylinder. It is very thin and is easily damaged if handled carelessly. Capillary tube should not have creases or cracks, as this will lead to refrigerant leakage inside the sensor and its incorrect operation. When removing the old thermostat, carefully pull the tube out of the mounting hole.
⚠️ Attention: The capillary tube of the thermostat is filled with gas or liquid under pressure. Do not bend or heat it, this may lead to depressurization and failure of the new device immediately after installation.
The next step is to disconnect the electrical wires. Before removing the terminals, it is strongly recommended to take a photo of the connection diagram or sketch it. Wire colors may not correspond to standard markings, and incorrect assembly may result in a short circuit. Disconnect the wires one at a time, marking them with a marker or using colored tags.
What to do if the wires are oxidized?
If a green or white coating is visible on the contacts, they must be cleaned to a metallic shine. Use fine sandpaper or a knife blade. After cleaning, it is recommended to treat the contacts with a spray for cleaning electrical contacts (Contact Cleaner) to improve conductivity and prevent further corrosion.
Connection diagram and installation of a new thermostat
Installation of a new regulator is carried out in the reverse order of dismantling. It is critical to choose a model with identical markings or a complete analogue. The parameters temperature range and the length of the capillary tube must match the original, otherwise the refrigerator will not work correctly.
When connecting the wires, be guided by the notes or photographs made earlier. If you are using a universal thermostat, the connection diagram may differ from the original one. In such cases, you must follow the instructions supplied with the new device or the color coding of the terminals.
Below is a table of contact correspondence for the most common types of thermostats installed in refrigerators Indesit:
| Contact type | Wire color (usually) | Function | Marking on the terminal |
|---|---|---|---|
| Power | Brown / Red | Supply voltage from the mains | L or 1 |
| Compressor | Black / Blue | Engine start | 2 or C |
| Lamp/Fan | Yellow / White | Lighting or No Frost | 4 or L |
| Grounding | Yellow-green | Protection | Earth |
After connecting the electrical part, you must carefully place the capillary tube in its normal place. It should fit snugly against the wall of the evaporator or fit into a specially designated hole. The fastening of the thermostat cylinder must be rigid, without play, so that heat exchange occurs correctly. Insufficient contact with the cooled surface will lead to a delay in the sensor response.
Setting up and testing operation
After assembling all the panels and returning the adjustment knob to its place, the refrigerator can be plugged in. You should not expect instant results - the system needs time to reach operating mode. The primary cooling cycle can take from 2 to 5 hours, depending on the volume of the chambers and the ambient temperature in the room.
During the first hours of operation, listen carefully to the refrigerator. The compressor must turn on and off at certain intervals. If the motor runs continuously for more than 6 hours without stopping, the new thermostat may require additional adjustment or is installed incorrectly. Mechanical models often have an adjustment screw hidden inside the case.
To fine-tune the temperature, use an external thermometer placed in a glass of water in the center of the refrigerator compartment. This will provide more objective data than built-in indicators. Achieve a value within +3...+5°C for the refrigerator compartment and -18°C for the freezer by rotating the control knob.
Common mistakes when replacing
Even experienced craftsmen sometimes make mistakes that can lead to repeated failure. One of the most common is ignoring the condition of the door seals. If the door does not close tightly, the cold leaves, and the thermostat will constantly keep the compressor on, trying to compensate for the heat inflow.
Another common mistake is incorrect installation of the capillary tube. If it touches metal parts other than the evaporator or is too far from the area being cooled, the temperature reading will be incorrect. It is also dangerous to use thermostats with a wider temperature range than required, as this can lead to freezing of food.
⚠️ Attention: Technical characteristics and internal structure of Indesit refrigerators may vary depending on the year of manufacture and the specific series. Always check the markings of the spare part with the documentation for your model or the data on the device nameplate.
Do not forget about the cleanliness of the contacts. Dirt, moisture or remnants of old solder can create additional resistance, heating the contacts and eventual burnout. A high-quality connection is the key to the durability of the repair.
When is it better to contact a professional
Although replacing a thermostat is considered a moderately complex repair, there are situations where independent actions can cause more harm than good. If you are not confident in your skills in working with electricity or are afraid of damaging the fragile elements of the cooling system, it is better not to take risks.
Also, the help of a specialist is necessary if the problem does not go away after replacing the thermostat. This may indicate a more serious problem, such as a clogged capillary system, a faulty start relay, or a refrigerant leak. Diagnosing these problems requires specialized equipment and knowledge.
Hidden system problems
Sometimes replacing the thermostat does not help because the compressor start relay is broken. The symptoms are similar: the refrigerator does not turn on or buzzes and clicks. Check the relay if the new thermostat does not solve the problem.
Frequently asked questions (FAQ)
Is it possible to install a thermostat from another brand of refrigerator on Indesit?
Theoretically, this is possible if the mounting dimensions, capillary tube length and temperature range match. However, the electrical connection diagram may differ. Universal thermostats (for example, K59, K50) are often suitable for replacing the original ones, but require careful study of the connection diagram.
Why does the new thermostat click, but the compressor does not start?
This may indicate a malfunction of the thermostat itself (the contacts inside do not close), a problem with the compressor starting relay, or a lack of voltage at the input to the thermostat. It is necessary to test the circuit with a multimeter at the moment of the click.
How often should the thermostat be changed?
The service life of the thermostat is usually 7–10 years, but it can fail even earlier due to power surges or mechanical damage. Planned replacement is not required, only in the event of a malfunction.
Does the length of the capillary tube affect the operation of the refrigerator?
Yes, it does critically. If the tube is too short, the sensing element will not be in the evaporator area and the refrigerator will not turn off. If it is too long, it may break. The length must correspond to the original.