Sudden failure of refrigeration equipment always becomes an unpleasant surprise, especially when large quantities are stored in the chambers food supply. One of the most common symptoms of a malfunction is the continuous operation of the compressor without shutting down or, conversely, the complete failure of the unit to start. Often the root of the problem is a broken thermostat, which stops correctly reading the temperature inside the chamber.
Refrigerators of the brand Ariston (now often combined with the Indesit brand) have proven themselves to be reliable equipment, but even with time mechanical and electrical components wear out. Replacing a thermostat yourself is a real task for a person who knows how to use a screwdriver and a multimeter. A competent approach will allow you to save on calling a technician and quickly bring the equipment back to life.
In this article we will analyze in detail the process of diagnosing and replacing the temperature sensor. You will learn how to choose the right analogue, safely dismantle the old part and set up a new operating mode. It is important to follow the sequence of actions so as not to damage other components of the cooling system.
Symptoms of a malfunctioning thermostat
Before you start disassembling, you need to make sure that the problem lies in the thermostat. There are characteristic signs that most likely indicate a breakdown of this control element. Ignoring these symptoms can lead to spoilage of food or failure of a more expensive compressor.
The main symptom is that the motor-compressor operates without interruption, even when ice has already formed inside the chamber or the temperature is clearly lower than necessary. In this case thermostat it simply does not open the electrical circuit, sending a signal to stop the engine. The opposite situation, when the refrigerator is silent and does not start, may also indicate that the contacts inside the sensor have oxidized and do not close.
⚠️ Attention: If you notice that it is too cold inside the refrigerator compartment and the compressor is humming continuously, immediately unplug the appliance. Long-term operation in this mode can lead to freezing of the evaporator and jamming of the compressor.
It is also worth paying attention to the regulator handle. If it turns with unnatural force or, conversely, too easily without characteristic clicks, this may indicate mechanical damage to the internal mechanism. Sometimes the malfunction manifests itself in the form of frequent switching on and off of the unit with short operating intervals.
- 🔌 The compressor does not turn off for a long time, creating a characteristic hum.
- ❄️ In the refrigerator compartment, food freezes, although this has not been observed before.
- 🔇 Complete absence reaction of the refrigerator to being plugged into the network (if the socket is working).
- 🎚️ The control knob scrolls endlessly or gets stuck in one position.
For accurate diagnostics, it is often necessary to ring the thermostat contacts with a multimeter. If, when the temperature of the capillary tube changes, the resistance does not change or the circuit does not close, the part requires replacement. In models Ariston with electronic control, instead of a mechanical thermostat, a sensor can be used, which is checked by resistance.
Selecting a suitable spare part for replacement
The success of the repair directly depends on the correctness of the selected spare part. Thermostats for refrigerators Ariston can vary in the length of the capillary tube, the type of contacts and the method of fastening. Using an unsuitable analogue will lead to incorrect operation of the equipment or the inability to install the part in its original place.
First of all, you need to find the markings on the body of the old thermostat. Usually it is applied to a metal or plastic case in the form of a set of letters and numbers. This is the code you should look for in spare parts catalogs. If the marking is erased, you can rely on the model of your refrigerator, but a visual comparison of the tube parameters remains mandatory.
Pay special attention to the length capillary tube. It can vary from 60 to 130 centimeters or more. If the new tube is too long, you can carefully roll it into a ring, but in no case bend or compress it, since there is a liquid or gas sensitive to deformation inside. A tube that is too short will not reach the desired temperature control zone.
⚠️ Attention: Do not try to shorten the capillary tube of the thermostat! This will break the tightness of the system and make the part completely inoperable. It is better to carefully place the excess length inside the case.
It is also important to consider the number of contacts. Standard mechanical thermostats often have three terminals: two for power and compressor connections, and one for ground or an indicator light. Before purchasing, compare the location of the terminals on the new and old part.
Necessary tools and preparation
To carry out a high-quality replacement of the thermostat in the refrigerator Ariston no complex professional equipment is required. A set of household tools, which most craftsmen have, is enough. However, preparing the workplace plays a critical role in the safety and convenience of the process.
The first and most important step is to completely disconnect the refrigerator from the electrical outlet. Remove the plug from the socket and make sure that access to it will not be blocked during operation. Next, you need to defrost the unit, if there is ice in the chambers, and free up space around the repair area.
For work you will need the following tools:
- 🔧 Screwdrivers (Phillips and flat) for dismantling panels and fasteners.
- 🔍 Multimeter for checking the circuit and diagnosing contacts.
- 🔪 A stationery knife or a thin awl for careful work with seals.
- 🧤 Gloves to protect your hands from sharp edges and dirt.
It is recommended to prepare a container in advance for collecting small fasteners so that they do not get lost. It is also useful to have a camera or smartphone handy. Before disconnecting the wires, take a photo of the connection diagram - this will help to avoid assembly errors when the colors of the wires may not be obvious.
Ensure the work area is well lit. The interior of a refrigerator is often dark, and in poor light it is easy to damage the plastic latches or miss an important fastening screw. If there is not enough natural light, use an additional lamp or flashlight.
Removing the old thermostat
The process of removing the thermostat in refrigerators Ariston usually begins with dismantling the plastic panel covering the temperature regulator. Depending on the model, it may be mounted with screws or held on by plastic latches. You must act carefully so as not to break the fragile plastic.
After removing the regulator handle and decorative trim, access to the insides opens. In some models, it is necessary to remove the top cover of the refrigerator or dismantle the ceiling light in order to gain access to the thermostat mounting location. The capillary tube often passes through the door seal or chamber wall, so removing it requires care.
The next step is to disconnect the electrical wires. Before removing the terminals, check again with the photo you took earlier. The wires can be secured with plastic blocks or simply put on the contacts. Carefully remove them, avoiding sharp jerks that could break the wire at the base.
The thermostat itself can be mounted on a bracket or inserted into a special groove. Loosen the fasteners and carefully remove the sensor along with the capillary tube. The tube passes inside the insulation channel, so you need to pull it smoothly, without jerking, so as not to damage the internal insulation of the refrigerator.
☑️ Preparation for dismantling
Installation of a new sensor and connection
Installation of the new thermostat is carried out in the reverse order. First, you need to correctly place the capillary tube in the channel through which the old one passed. Make sure that the sensing element of the tube is tightly against the wall of the evaporator or is in the area where the temperature was previously monitored.
Fix the thermostat housing in its original place. If the model differs in size, you may need to be more inventive with the fastening, but in most cases, original spare parts or high-quality analogues will fit into place without problems. The main thing is to ensure reliable fixation so that the vibration of the compressor does not damage the contacts.
Connecting the wires is the most crucial moment. Use the diagram you photographed earlier. Usually the wires are color coded, but you shouldn't rely on that alone. Securely attach the terminals to the contacts of the new thermostat. If the contacts are oxidized or loose, they can be carefully tightened with pliers, but without fanaticism.
| Parameter | Old thermostat | New thermostat | Status |
|---|---|---|---|
| Model (code) | K59-L1234 | K59-L1234 | Coincident |
| Tube length | 90 cm | 100 cm | Acceptable |
| Number of contacts | 3 | 3 | Coincident |
| Mounting type | Bracket | Bracket | Coincidious |
After connecting the electrical part, reassemble the housing in the reverse order. Reinstall lamp shades, panels and decorative trims. Make sure all screws are tight and the plastic latches click into place. There should be no unnecessary parts or gaps left.
What to do if the capillary tube is too long?
If the new tube is significantly longer than the old one, it cannot be cut. Carefully roll the excess into a ring with a diameter of at least 3-4 cm and place it inside the refrigerator body or behind the back panel, avoiding sharp edges and moving parts.
Setting up and testing operation
After assembly, the refrigerator can be plugged in. However, you should not immediately load it with products. Let the unit run idle for at least 2-3 hours. This will allow the system to reach operating mode and stabilize temperature indicators.
Pay attention to the compressor operating cycle. After the initial temperature rise, the engine should turn off. If the refrigerator gets cold and turns off, it means replacing the thermostat it was successful. If the motor continues to hum without interruption, you may need to adjust the screws on the thermostat itself (if they are available) or check the tightness of the system.
In some cases, it may be necessary to adjust the temperature range. There are sometimes adjusting screws on the thermostat housing that control the on and off temperatures. They should be twisted very carefully, making no more than a quarter of a turn at a time, and waiting for the result.
⚠️ Attention: Technical characteristics and location of the adjusting elements may vary depending on the specific model and year of manufacture of the refrigerator. Always check the manufacturer's technical documentation for your series of equipment.
Check the operation of the indicator light (if provided for by the design). It should light up when the compressor stops. Also make sure that excessive ice does not form in the chamber during the first day of operation, which could indicate that the operating cycle is too long.
Possible errors and their elimination
Even if you carefully follow the instructions, nuances may arise. One of the common mistakes is poor contact in the terminal block. If the refrigerator does not turn on, check whether the wires are fully inserted. Sometimes oxidation of contacts on a new thermostat requires cleaning them with fine sandpaper.
If the compressor works but does not turn off, the problem may not be in the thermostat, but in a freon leak or a malfunction of the motor itself. However, if you changed the sensor, check whether the capillary tube fits tightly to the evaporator. Poor thermal contact will lead to a delayed sensor response.
There are cases when the new thermostat has a slightly different temperature range. This can lead to the food in the refrigerator compartment freezing or, conversely, spoiling. In such a situation, only replacing it with a model with more accurate parameters or careful adjustment will help.
Do not forget about safety. All work on electrical components must only be carried out with the device completely de-energized. If you feel unsure of your abilities or see melted wires, it is better to contact a professional technician.
Is it possible to use a thermostat from another brand, for example, Indesit?
Yes, in many cases, thermostats from Indesit refrigerators are suitable for Ariston, since these brands have used common platforms and components for a long time. The main thing is the coincidence of the fitting dimensions, the length of the capillary tube and the electrical parameters of the contacts.
Why does the refrigerator not turn off after replacing the thermostat?
There may be several reasons: the new thermostat itself is faulty (defective), the wires are incorrectly connected, there is a refrigerant leak or the compressor is jammed. It is also possible that the capillary tube does not fit tightly to the cooled surface.
How to understand that the thermostat is working without a multimeter?
It is difficult to give an exact answer without instruments, but you can “short circuit” the wires going to the thermostat (if there are two of them). If after connecting the wires the compressor starts, then the circuit is intact, and the problem is most likely in the regulator itself, which does not close the contact. Be careful to only do this with the plug disconnected and securely insulate the connection before turning it on!
Does it need to recharge the freon after replacing the thermostat?
No, replacing the thermostat does not affect the refrigerant circuit. The freon is in a sealed system, and the mechanical temperature sensor does not have direct contact with it (it reacts to the temperature of the wall or air). Therefore, refueling is not required.