Sudden increase in temperature in refrigeration chamber or, conversely, excessive freezing of the rear wall often indicates a malfunction of the temperature control system. Thermostat (or thermostat) is a key element that commands the compressor to turn on or off, maintaining the desired climate condition. When this unit fails, the refrigerator stops freezing or works without stopping, which leads to increased energy consumption and food spoilage.
Equipment owners Ariston are often faced with the need to understand where exactly this sensor is located in order to diagnose or replace it. The location of the thermostat may vary depending on the model and year of manufacture of the device: it can be hidden behind a plastic panel, built into the control unit, or brought out in the form of a rotary knob. Ariston refrigerators They are famous for their reliability, but even they are subject to natural wear and tear of components.
In this article we will look in detail at how to find thermostat in various modifications, what tools are needed for work and how to distinguish a sensor failure from other malfunctions. It is important to understand that DIY repairs require caution since you will be working with electrical components. If you are not confident in your abilities, it is better to turn to professionals, but knowledge of the theory will help you more accurately describe the problem to the specialist.
Operation principle and types of Ariston thermostats
Before looking for an installation location, you need to figure out what type of regulator is used in your device. In technology Ariston, especially in models of previous years of production, mechanical thermostats were most often used. They are a sealed capsule with a gas-filled tube (bellows), which responds to changes in pressure with changes in temperature. When the temperature in the chamber rises above the set point, the gas expands and the contacts close, starting the compressor. Modern models can be equipped with electronic temperature sensors that transmit data to the main control module. In such systems, the concept of “thermostat” is transformed into an electronic sensor located directly inside the chamber or in the cold air supply channel. Mechanical models, such as compressor.
Modern models can be equipped with electronic temperature sensors that transmit data to the main control module. In such systems, the concept of “thermostat” is transformed into an electronic sensor located directly inside the chamber or in the cold air supply channel. Mechanical models such as K 17B or K 59usually have an external adjustment knob, while electronic models are controlled through the display on the front panel of the refrigerator.
⚠️ Attention: Before starting any work to find or replace the thermostat, be sure to disconnect the refrigerator from the electrical outlet. Working with live electrical wiring is deadly.
Understanding the type of regulator you have is critical to where to look. If you have a mechanical model, the thermostat is physically connected to the chamber by a capillary tube. If it’s electronic, you need to look for a small electronic component, often mounted on a wall or in an air duct. In both cases malfunction leads to similar symptoms, but the diagnostic methods are different.
Localization of the thermostat in single-chamber models
In classic single-chamber refrigerators Ariston the thermostat is most often located inside refrigeration compartment. This is the most accessible option for diagnosis. You should look for it at the top of the camera; it is often hidden behind a decorative overlay or plastic casing. In some models, the temperature control knob is located on the ceiling of the chamber, and the mechanism itself is located immediately behind it.
To access the unit, you will probably have to remove the lamp shade or protective cover, which is secured with latches or screws. Under this plastic you will see a rectangular or square block with wires going to it. It is from this block that a thin capillary tubecomes, the end of which is fixed to the evaporator or hangs freely in the air of the chamber (depending on the design).
- 🔍 Inspect the upper right or left corner of the fridge compartment - the mounting plate is most often hidden there.
- 🔧 Look for the screws securing the plastic panel; they may be hidden under decorative plugs.
- ❄️ Pay attention to the tube coming from the unit: it should not be pinched or damaged.
It is important to note that in older models the thermostat can be installed outside, on the back wall of the case, and only goes inside sensitive tube. However, most household models Ariston are characterized by internal installation. If you removed the panel and did not find anything resembling a thermostat there, check the area around the evaporator hidden behind the back panel of the chamber.
Searching for the sensor in two-chamber No Frost refrigerators
In two-chamber units with a system No Frost the situation becomes more complicated. Here the thermostat (or temperature sensor) is often located not in the main chamber, but in the evaporator area, which is located behind the rear wall of the freezer compartment. It is more difficult to get to it, since partial disassembly of the internal space of the freezer is required.
In such models thermostat it can be built into the defrosting system or located in the air duct connecting the freezing and refrigerating chambers. If you have an electronically controlled refrigerator, temperature sensors are often located at several points: one monitors the air in the refrigerator compartment, another in the freezer, and a third on the evaporator. Mechanical thermostats in No Frost systems are less common, but if they are present, their capillary tube passes through the entire chamber to the evaporator.
To access the sensor in the No Frost system, you usually need to:
- Empty the freezer compartment of food.
- Remove the shelves and drawers.
- Remove the back panel of the freezer (it can be secured with screws or latches).
- Locate the evaporator and sensors suitable for it.
⚠️ Attention: In No Frost systems, plastic elements may be fragile due to low temperatures. Allow the refrigerator to thaw or proceed with extreme caution so as not to break the panel fastenings.
If you find that the sensor is located deep in the air duct, do not try to remove it by force. Often, replacement requires removing the entire evaporator unit. In models Ariston with full automation, replacing the sensor may require reprogramming the control module, so before intervening, check the model of your device.
How to distinguish a sensor from a heating element?
A heating element (heating element) usually looks like a metal tube or spiral in a casing and has greater resistance. The sensor is a small plastic or metal tip with two thin wires.
Instructions for dismantling and accessing the unit
The process of dismantling the thermostat in the refrigerator Ariston requires consistency and accuracy. First, make sure you find the item you're looking for. It always has electrical contacts (usually 2 or 3 wires) and a mechanical connection to the camera (tube or housing). If the thermostat is mechanical, there will be an adjustment screw or knob on it.
To work, you will need basic tools: Phillips and flat-head screwdrivers, pliers and, possibly, a multimeter for testing. Before disconnecting the wires, be sure to remember or photograph the connection diagram. Mixed-up contacts can lead to a short circuit or improper operation of the compressor.
☑️ Tools for replacing the thermostat
Sequence of actions for dismantling:
- Disconnect the refrigerator from network.
- Remove all interfering shelves and decorative panels.
- Unscrew the thermostat mount (if there is one).
- Carefully pull the sensitive tube out of the seat (in mechanical models).
- Disconnect terminals with wires.
Pay special attention capillary tube. It is very thin and easily damaged. If you accidentally bend or puncture it, the coolant will escape and the thermostat will have to be thrown away. When installing a new regulator, the tube must be laid in exactly the same way as the old one was laid, using the same clips or grooves.
Diagnostics of thermostat malfunctions
How to understand that the problem is in the thermostat and not in the compressor or freon leak? There are several characteristic signs. Firstly, the refrigerator can work continuously without turning off, and at the same time it is very cold or just humming. Secondly, the device may not turn on at all, even if you directly apply voltage to the compressor (this requires the skills of an electrician).
The easiest way to check a mechanical thermostat is the elimination method. If you do not hear a click when you turn the adjustment knob and the compressor does not start, the contacts inside may be stuck or oxidized. You can also “close” the thermostat contacts directly (temporarily!). If after this the refrigerator starts working, it means the thermostat is faulty.
For more accurate diagnostics, use a multimeter in dial mode:
- 🔌 Remove the thermostat and disconnect the wires.
- ⚙️ Switch the multimeter to resistance measurement mode.
- 📉 At room temperature, the contacts should ring (resistance is close to 0).
- ❄️ If you put the sensor in the freezer for 15 minutes, the contacts should open (resistance is infinity).
If the circuit does not break when cooling or does not close when heating, element requires replacement. Electronic sensors are checked by measuring their resistance, which should change smoothly depending on the temperature, according to the characteristics table for a specific model.
Compatibility table and analogues of thermostats
When replacing, it is important to choose the right analogue. Thermostats Ariston are often compatible with parts from other brands, such as Indesit, Stinol or Whirlpool, since they were produced in the same factories. However, the response parameters may differ.
| Thermostat model | Mounting type | Tube length | Application |
|---|---|---|---|
| K 17B | Threaded | 0.75 m | Single-chamber refrigerators |
| K 59-L1275 |