Finding the place where temperature sensor in the refrigerator Indesitoften becomes necessary when problems arise with cooling or a constant cycle of turning the compressor on and off. Owners of household appliances are faced with a situation when the chamber freezes too much or, conversely, food begins to spoil due to insufficient cold. Understanding the design of the climate control system allows you to quickly diagnose a malfunction and decide whether to repair it yourself or call a technician.
The exact location of the sensor depends on the specific model of your unit and the type of defrosting system installed. In old models with mechanical control, the thermostat plays the role of a regulator, and in modern systems No Frost and Full No Frost electronic temperature sensors (thermistors) are responsible for control. The difference between them is fundamental: a mechanical device physically opens the circuit, while an electronic device only transmits resistance data to the control board.
Before proceeding with disassembly, it is necessary to de-energize the device and prepare the necessary tools. Errors in diagnosis can lead to the purchase of unnecessary parts, so it is important to accurately determine the type of control of your refrigerator. In this article we will analyze in detail where to look for sensors in different modifications Indesit, how to check their performance and what to look for when replacing.
Types of temperature control systems in Indesit
To find a sensor, you need to understand what control system your refrigerator uses. In the line Indesit there are three main options, and each of them has its own specific arrangement of sensitive elements. Mechanical thermostats are usually hidden inside the chamber or behind the back wall, while electronic thermistors are often built into the evaporator or air ducts.
In models with a drip defrost system and mechanical control, the thermostat is a box with an adjustment knob. Its capillary tube goes deep into the chamber or behind the casing. If you have a modern unit with an electronic display on the door, then most likely there are thermistors installed inside, which look like small plastic cylinders with two wires.
⚠️ Attention: Replacing a mechanical thermostat with an electronic one (or vice versa) is impossible without completely re-soldering the control board and changing the connection diagram. Install only original spare parts or their direct analogues.
Electronic sensors in systems No Frost are often responsible not only for air temperature, but also for controlling evaporator defrost. Their failure can lead to ice forming on the fan and stopping the circulation of cold air, even if the compressor is working properly. Therefore, it is important to distinguish between the air sensor in the chamber and the defrost sensor located on the evaporator itself.
Where the sensor is located in models with mechanical control
In refrigerators Indesit of the old model or budget series, the thermostat is located directly inside the fridge compartment. Most often it is located in the upper right corner, hidden under a plastic casing or integrated into the lighting control panel. To get to it, sometimes it is enough to simply remove the protective cover without resorting to complete disassembly of the unit
If the regulator handle is moved outside to the front panel, then the thermostat mechanism itself is hidden behind this panel. To access it, you will need to remove the top cover of the refrigerator or dismantle the front cover. The capillary tube in such models passes through the door seal or is inserted behind the back wall of the chamber, where it is fixed in a special hole.
The key point when searching is the characteristic click that the thermostat makes when switching modes. If you turn the handle and hear a click, it means that the mechanism is somewhere nearby and its contacts are opening. In some models Indesit the thermostat may be hidden behind the lamp shade, which is secured with latches or one screw.
- 🔍 Look for the thermostat in the upper right corner of the refrigerator compartment under a plastic cover.
- 🔧 To gain access, you may need to remove the top cover of the refrigerator or the lamp shade lamps.
- ❄️ The capillary tube is sensitive to bends, so be careful when removing the housing.
When dismantling, it is important not to damage the capillary tube, since it is filled with freon (or other refrigerant) under pressure. A puncture of the tube will lead to a gas leak and failure of the thermostat, and will also require refilling the refrigerator. Temperature sensor in such systems, this is a sealed unit that cannot be repaired, only replaced.
Location of thermistors in No Frost and Full No Frost systems
In more complex models Indesitequipped with the system No Frostsensors Temperature gauges (thermistors) are located in the evaporator area, which is hidden behind the back panel of the freezer or refrigerator compartment. Getting to them is more difficult: you will need to remove all the shelves, drawers and dismantle the plastic back wall covering the fan and defrost heater.
Usually several sensors are installed in such refrigerators. One is responsible for the temperature of the air in the chamber (often located at the top of the air duct), another controls the temperature of the evaporator (attached to the radiator tubes or lamellas), and the third can monitor the condition of the drip tray. They are all connected to a common electronic board, which is located at the bottom of the refrigerator or behind the base.
Thermistors look like small plastic “bullets” or cylinders with a diameter of about 5-8 mm with two thin wires. They have no moving parts, unlike mechanical thermostats. Their resistance changes depending on the temperature, which is what the control board reads. Often they are filled with sealant or secured in special seats on the evaporator.
⚠️ Attention: When removing the back panel in the freezer, be prepared for the fact that there may be ice there. Do not use sharp objects to chip ice near the sensors and evaporator tubes to avoid puncturing the cooling circuit.
If your refrigerator displays a temperature-related error code (for example, blinking lights), this often indicates an open circuit in the thermistor or a change in its resistance beyond acceptable limits. In such cases, a visual inspection of the connection location and checking the integrity of the wires is the first diagnostic step.
How many sensors are there in a No Frost refrigerator?
The standard Indesit No Frost model usually has 2 or 3 thermistors: one in the refrigerator compartment (air), one or two in the freezer compartment (evaporator and air). The exact quantity depends on the specific series and year of manufacture.
Diagnostics and checking the functionality of the sensor
Before buying a new part, you need to make sure that this is the problem. To check a mechanical thermostat, you can use the contact closure method: if, when connecting the wires, the refrigerator starts and does not turn off, then the old thermostat is faulty. However, for electronic thermistors it is necessary a multimeter to measure resistance.
The process of checking a thermistor consists of measuring its resistance at room temperature and comparing the obtained data with reference values. Typically, at room temperature (+20...+25°C), the resistance of the thermistor Indesit is about 5-7 kOhm (kilo-ohm). When cooling, the resistance should increase, and when heating, it should fall (or vice versa, depending on the type of NTC or PTC thermistor).
If the multimeter shows infinity (open) or zero (short circuit), the sensor is clearly faulty. It is also worth checking the integrity of the wires going from the sensor to the control board. Often the wires break at bending points or become bent during defrosting.
Below is a table with approximate resistance values for typical thermistors used in technology Indesit. Please note that the values may vary slightly depending on the specific model and manufacturer of the spare part.
| Temperature (°C) | Resistance (kOhm) - NTC Type | Sensor status | System response |
|---|---|---|---|
| +25°C | 5.0 - 7.0 kOhm | Normal | Normal operation |
| 0°C | 15.0 - 18.0 kOhm | Normal | Cooling |
| -18°C | 40.0 - 50.0 kOhm | Normal | Deep freezing |
| Any | 0 kOhm or ∞ | Faulty | Error / Code on display |
☑️ Checklist for checking the sensor
The process of replacing the temperature sensor
Replacement temperature sensor in the refrigerator Indesit requires accuracy and adherence to the sequence of actions. After you have determined the location of the faulty element and purchased a new spare part, you must completely defrost the unit (at least 24 hours) if work was carried out on the system No Frost and the evaporator was removed.
For mechanical thermostats, it is important to correctly install the sensitive tube. It should go into the same hole to the same depth as the previous one. If the tube dangles or touches the walls of the chamber incorrectly, the refrigerator will not work correctly: either it will not turn off or it will not gain temperature. The tube retainer is often specially color-coded.
When replacing electronic thermistors in systems No Frost it is critical to use heat-resistant sealant to secure the new sensor in place of the old one. Moisture in the chamber is the main enemy of electrical contacts. The junction of the wires is often additionally insulated with heat shrink. After assembling all the panels and connecting them to the network, you may need to reset the error in the control board memory.
- 🔌 Be sure to disconnect the refrigerator from the power supply before starting any work.
- ❄️ Let the unit defrost completely if you removed the back panel of the freezer.
- 🧴 Use food-grade silicone sealant for fixing the thermistor on the evaporator.
After replacing and turning on the refrigerator, let it work for several hours without loading food. This will allow the system to return to operating mode and stabilize the temperature. If the compressor operates cyclically (turns on and off), and the temperature in the chambers is normal, then the replacement was successful.
Common mistakes during self-repair
One of the most common mistakes is an attempt to replace an electronic thermistor with a mechanical analogue. This is technically impossible without a deep rework of the entire control system, since the principles of their operation are radically different. The control board simply will not understand the signals from the mechanical circuit breaker.
Also, owners often ignore the condition of the wires going to the sensor. By changing the thermistor “pestle” itself, they leave behind old, possibly oxidized or broken wires. This leads to the problem returning after a short time. Always check the integrity of the wiring up to the control board itself, especially in the places where they exit from plastic boxes.
Another mistake is incorrect installation of the capillary tube of the mechanical thermostat. If you do not fix it in the right place or install it too deep/shallow, the refrigerator will “lie” about the temperature inside the chamber. As a result, food may freeze at the back wall or, conversely, leak.
⚠️ Attention: Do not use regular electrical tape to insulate connections inside the refrigerator. Over time, it will dry out from cold and moisture, which will lead to oxidation of the contacts. Use only heat-shrinkable tubes.
Don't forget about safety. Although the voltage in the sensor circuit is usually low, the refrigerator itself is connected to a 220V network. Careless handling of compressor or defrost heating element power cables can be life-threatening. If you are not confident in your skills in working with electricity, it is better to entrust the repair to professionals.
Why does the new sensor not work?
If after replacing the sensor the problem does not disappear, the control board itself may be faulty, the contacts in the connector have oxidized, or a sensor with inappropriate resistance parameters has been installed. Also, the problem may be a freon leak, which the sensor cannot correct.
Questions and answers (FAQ)
How can you tell that it is the sensor and not the compressor that is faulty?
If the compressor does not turn on at all, but the light in the chamber is on and you hear the relay clicking, maybe it's the thermostat. If the compressor hums, but there is no cold, or it works without stopping, this may also indicate a sensor. Only a test with a multimeter will give you an accurate answer.
Is it possible to temporarily bypass (short-circuit) the sensor to make the refrigerator work?
For a mechanical thermostat, closing the contacts will force the compressor to work constantly, which will lead to freezing of food. For an electronic thermistor, a short will most often cause an error on the board, and the system will go into protection, turning off the compressor completely. You cannot operate a refrigerator without a sensor.
Where to buy an original sensor for Indesit?
Original spare parts can be found in specialized stores of spare parts for household appliances, indicating the exact model (serial number) of your refrigerator. Universal analogues are also suitable if their resistance matches the original at room temperature.
Why does the refrigerator not turn off after replacing the sensor?
Perhaps a sensor with different resistance parameters is installed, the capillary tube is installed incorrectly (in mechanics), or the problem lies not in the sensor, but in a freon leak or a malfunction of the compressor itself. The starting relay-regulator could also be stuck.