A sudden cessation of operation of a refrigeration unit or, conversely, its endless operation without shutting down often indicates a failure of one of the key elements of the control system - the thermal relay. Equipment owners Indesit face this problem regularly, since this unit is subject to natural wear and voltage fluctuations. If your the refrigerator has stopped freezing or started to work in emergency mode, first of all you should pay attention to the thermostat.
Understanding the principle of operation of this device allows you not only to save on calling a technician, but also to quickly return the equipment to working order. Thermal relay responsible for turning it on and turning off the compressor depending on the temperature in the chamber. In this article we will look in detail at how to carry out diagnostics, what tools will be needed and what to pay special attention to when checking the contacts.
Before starting disassembly, you need to make sure that the problem lies precisely in the mechanics or electrics of the relay, and not in a freon leak or a malfunction of the motor-compressor itself. Competent diagnostics starts with an analysis of the symptoms that your unit exhibits. We will consider all stages of testing from visual inspection to checking the circuit with a multimeter.
Symptoms of a thermal relay malfunction
You can determine a thermostat breakdown by characteristic signs that cannot be ignored. Most often, users notice that the refrigerator does not turn on at all, or it works non-stop, trying to cool the camera to unrealistically low temperatures. In some cases, the unit may turn on for a few seconds, hum, and then click and go silent again.
The second obvious sign is the absence of a characteristic click when the set temperature is reached. If you hear the motor running, but the shutdown click is not heard even after an hour of operation, this is a sure signal that the contacts are stuck or the mechanism is broken. It is also worth paying attention to the condition of the products: if they freeze to smithereens or, on the contrary, begin to deteriorate, thermostat requires checking.
⚠️ Attention: If the refrigerator compressor hums, but does not start, and after 10-20 seconds there is a click and it goes silent, the problem may not only be thermal relay, but also in the start-up relay or the compressor itself. Do not rush to change parts without an accurate diagnosis.
There are a number of indirect signs that may also indicate problems with temperature control. For example, a huge “coat” of ice may form on the back wall of the refrigerator compartment, although this has not been observed before. Or it becomes too warm inside the chamber, although the regulator is turned to maximum cold.
- ❄️ The compressor works continuously without stopping to rest.
- 🔇 There is a complete absence of sounds from the motor when the refrigerator is plugged in.
- 🧊 The products in the refrigerator compartment are either frozen or completely defrosted.
- 🔊 Frequent clicks when trying to start the engine.
Preparation for diagnostics and safety measures
Before you start checking the thermal relay, you need to prepare a workplace and tools. You will need a Phillips and flathead screwdriver to remove the panels, as well as a working multimeter (tester) to measure the circuit resistance. Without a multimeter, it is almost impossible to carry out an accurate diagnosis, since a visual inspection does not always reveal internal breaks.
The most important step is to ensure personal safety. Any work on electrical components should only be carried out with the device completely disconnected from the mains. Unplug the socket and ensure that electrical parts are safe to access. If there is water on the floor, it must be wiped up immediately to avoid a short circuit.
For models Indesit with an overhead thermostat (inside the refrigerator compartment), it is often necessary to remove the plastic cover or the light bulb to get to the mounting screws. In some cases, for example, in series models CIS or DS, the thermal relay may be hidden behind a decorative panel on the ceiling of the chamber.
☑️ Preparation for testing
Don't forget to write down or photograph the color coding of the wires before disconnecting them. Although the connection diagram is standard, in different modifications Indesit the insulation colors may differ. An error during assembly can lead to failure of the new relay or even the compressor.
Where is the thermostat located in the Indesit refrigerator
The location of the thermostat depends on the specific model and year of manufacture of your refrigerator. In most modern models Indesit with one compressor, the thermal relay is located inside the refrigeration chamber. Usually this is a plastic box mounted on one of the side walls or on the ceiling of the chamber.
To get to the device, it is often necessary to remove the top shelf of the refrigerator compartment and unscrew the fasteners holding the plastic casing. In some older models, the thermostat may be located behind the back panel of the freezer or in a niche above the door. In two-chamber models with a No Frost system, the sensor is often built into the defrost system, but the main compressor control thermostat remains in the refrigerator compartment.
If you cannot find the device visually, focus on the temperature control knob. The capillary tube that comes from the handle is always connected to the thermostat itself. Follow the path of this tube - it will lead you straight to the element you are looking for. Be careful, the capillary is very thin and easily damaged.
| Indesit model | Thermal relay location | Access type | Dismantling features |
|---|---|---|---|
| Indesit CIS 018 | Inside, left top | Removing the ceiling | You need to release the latches |
| Indesit DS 418 | Inside, top right | Removing the panel | Fixing with screws |
| Indesit IB 18 | Inside, on the wall | Removing the shelf | Hidden fasteners |
| Indesit EF 18 | Behind the back wall | Disassembling the camera | Requires complete analysis |
It is important to understand that in some budget models, access to the thermal relay may be complicated by the design of the internal lining. If you see that you need to break the plastic or use excessive force to gain access, it is better to stop and study the instructions specifically for your model.
What to do if the capillary tube bursts?
If during the dismantling process you damaged the thin copper capillary tube, the thermal relay must only be replaced. Repairing the capillary at home is impossible, since the gas filling the bellows will escape through the damage, and the relay will stop responding to temperature.
Removing the thermostat for testing
The process of removing the thermostat requires care. After removing the decorative panels, you will see the relay housing, which has several wires going to it. The first step is to disconnect the terminal block or individual wires. To do this, it is convenient to use a thin flat-head screwdriver to press out the terminal clamps.
The thermostat itself is usually attached to the refrigerator body or to the evaporator using a bracket or screw. After unscrewing the fasteners, carefully pull out the device. Pay attention to the capillary tube: it should not have creases or sharp bends. If you remove the relay completely, try not to pull the tube sharply, so as not to break the tightness of the system.
On some models Indesit the thermal relay may be “stuck” to the evaporator due to ice. In this case, do not use force. Allow the refrigerator to defrost completely for 10-12 hours and the ice will melt, freeing the part. An attempt to tear off a frozen relay can lead to a break in the capillary.
- 🔌 Disconnect the wires, remembering their location.
- 🔩 Unscrew the fastening screw or holder bracket.
- ❄️ Make sure that there is no ice crust around the housing.
- 👐 Carefully remove the thermostat, supporting the capillary.
After removal, carefully inspect the housing for cracks, traces of burning or melting. If you see black spots on the plastic or smell burning insulation, this may indicate a short circuit inside the appliance. However, the absence of external defects does not guarantee the serviceability of the internal mechanics.
Checking the thermal relay with a multimeter
The most reliable way check the thermal relay is to use a multimeter in resistance measurement mode (Ohm). To begin, set the device switch to the 200 Ohm or 2000 Ohm position. If you have an analog tester, select the dialing mode. Prepare two probes and make sure that the device is working (when the probes are closed, the arrow should deflect or the indicator should light up).
At room temperature, the thermal relay contacts should be closed (unless these are specific models with normally open contacts, which is rare for refrigerators). Place the multimeter probes on the relay contacts. If the screen displays “1” or infinity, the circuit is open and the relay is faulty. If you see values close to zero (0-5 Ohms), then the circuit is intact.
For a more accurate check, you can place the thermal relay sensor (capillary tube with a flask) in a container with cold water and ice. After a few minutes, when the temperature drops below the response threshold, a click should be heard and the contacts should open (the resistance will become infinite). If this does not happen, the mechanism is stuck.
⚠️ Attention: Never check the resistance while the thermal relay is connected to the network or while voltage is applied to it. This will instantly damage the multimeter and can be dangerous to your life.
It is also worth checking if there is a breakdown in the case. Apply one probe to any contact, and the other to the metal body of the relay. The device should show infinite resistance. If the multimeter rings the circuit, it means that the insulation is broken, and such a relay cannot be used - this can lead to an electric shock when touching the refrigerator.
Replacing and setting up a new thermostat
If the diagnostics showed a malfunction, the only correct solution is replacing the thermal relay to a new one. It is not economically feasible to repair this unit, since the cost of a new element is low, and the reliability of a restored one will be low. When purchasing, pay attention to the marking: it must match the original or be a universal analogue with suitable parameters.
Installation is carried out in the reverse order of removal. Insert the capillary tube into the same hole where it was previously attached. The length of the immersion part of the tube is critical: if it is too short, the refrigerator will “lie” about the temperature and turn on frequently; if it is too long, it may freeze.
After connecting the wires and assembling the plastic panels, turn on the refrigerator. Initial setup is usually not required if you have installed an analogue with the same characteristics. However, it is recommended to check the operation on the first day: the refrigerator should reach the temperature and turn off.
Don't forget to check the tightness of the connections if you touched the tube. There should be no gaps around the entry point of the capillary into the chamber through which the cold escapes. If necessary, seal the hole with mounting foam or a special sealant to prevent the formation of condensation and ice inside the case.
Frequently asked questions (FAQ)
Is it possible to temporarily close the thermostat to make the refrigerator work?
Technically, you can close the contacts and the compressor will work. However, this is strictly not recommended for long-term use. Without a thermostat, the refrigerator will operate continuously, which will lead to freezing of food, overheating of the compressor and significant waste of electricity. This is only permissible as a short-term measure to defrost or check the compressor.
Why does the new thermostat click, but the refrigerator does not turn off?
Perhaps the capillary tube of the new relay is not immersed deep enough in the cooling zone or is in poor contact with the evaporator. Also, the reason may be incorrect calibration of the new relay or a freon leak, due to which the temperature in the chamber simply does not reach the shutdown threshold, even if the relay is working properly.
How to distinguish a breakdown of the thermal relay from a malfunction of the compressor?
If, when the relay contacts are closed directly (bypassing the relay), the compressor starts and works normally, it means that The motor is fine, but the problem is in the relay. If, with a direct connection, the motor hums, but does not turn, or does not make any sounds, the problem is in the compressor or the start relay.
Is it necessary to defrost the refrigerator before replacing the thermostat?
Yes, completely defrosting the refrigerator (at least 10-12 hours) is strongly recommended. This will avoid damage to fragile plastic elements in the cold, make it easier to dismantle frozen parts and ensure safety when working with electrical contacts.
Where to buy an original thermal relay for Indesit?
Original spare parts and high-quality analogues can be found in specialized stores of spare parts for household appliances or at official service centers. When ordering, be sure to tell the seller the exact model of your refrigerator, indicated on the nameplate inside the chamber.