Sudden cessation of the cooling system or, conversely, excessive freezing of food often indicates a malfunction of the temperature control. Owners of LG equipment may encounter a situation where the compressor hums continuously, without turning off, or does not start at all, ignoring the needs of the internal volume of the chamber for cold. It is thermostat (or thermostat) that is the very element that is responsible for maintaining a given climate inside the unit, closing and opening the electrical circuit of the compressor depending on the temperature readings.
Understanding where it is thermostat on an LG refrigeratoris the first and most an important step for self-diagnosis of the malfunction. The location of this unit may vary significantly depending on your device model, year of manufacture, and type of control system - mechanical or electronic. In older models with mechanical control, the sensor is often hidden behind plastic panels, while in modern No Frost systems, the role of the regulator is performed by a complex electronic unit, distributed in different zones.
Before you begin disassembling the case and searching for hidden elements, you need to clearly determine the type of control of your refrigerator. If you have a wheel or slider on the panel with numbers from 1 to 7, you have classic mechanics, and a physical thermostat is definitely present in the design. If the temperature is set by buttons and displayed on a digital display, then you are dealing with electronic system, where the functions of the thermostat are distributed between several sensors located in different parts of the chamber.
Peculiarities of location in models with mechanical control
In classic LG refrigerators equipped with mechanical controls, the thermostat is a separate device with a capillary tube that is sensitive to temperature changes. Most often, the thermostat housing itself, where the contact group is located, is hidden inside the main volume of the refrigeration chamber or outside the housing in the technical compartment. The exact location depends on the design of the evaporator and how the capillary tube is installed.
The most common scenario for models with a top freezer is the location of the thermostat behind a plastic trim on the ceiling of the refrigerator compartment or inside a lampshade. To get to it, you often need to dismantle the top shelf and carefully remove the decorative cover under which it is hidden mechanical thermostat. In this case, the capillary tube can be fixed to the evaporator or laid inside the chamber wall.
In some modifications, especially in older series, the thermostat can be moved outside the fridge compartment. In this case, it is located in a niche above the door or in the upper part of the case, which is accessible after removing the top cover of the entire refrigerator. This complicates diagnostics, as it requires partial disassembly of the outer casing of the unit.
It is important to note that in models with a mechanical type system, the thermostat is often installed in cold air exhaust channel or directly to the evaporator, which is located behind the rear wall. This means that replacing it may require defrosting the unit and removing the back panel inside the chamber, which is a more labor-intensive procedure. No Frost a mechanical type thermostat is often installed in the cold air exhaust duct or directly on the evaporator, which is located behind the rear wall. This means that replacing it may require defrosting the unit and removing the back panel inside the chamber, which is a more labor-intensive procedure.
Why is the thermostat hidden deeply?
Manufacturers hide the thermostat behind panels for a reason. This is protection against accidental damage when loading products and preventing unauthorized intervention in settings, which could lead to compressor failure due to incorrect temperature conditions.
Electronic systems: where to look for temperature sensors
Modern LG refrigerators, controlled electronically, do not have a single thermostat in the usual sense. Instead, thermal sensors (thermistors) are used, which are small elements that change their resistance depending on the ambient temperature. These sensors are scattered throughout various areas of the unit to provide precise control in each compartment.
The main sensor that controls the operation of the compressor in the refrigerator compartment is usually located in the duct or behind the rear wall. In models with Door Cooling+ or similar blowing systems, the sensor may be located in the upper part of the rear panel, where cooled air enters. Access to it is often opened after removing the decorative grille or panel covering the circulation system.
In the freezer, the sensor is usually built directly into the evaporator or attached to its surface. In systems Total No Frost this element is critical for managing defrost cycles. An error in its readings can lead to either freezing of the evaporator or a complete stop of cooling.
⚠️ Attention: LG electronic sensors are very sensitive to static electricity and mechanical shock. When touching contacts with your hands, use antistatic gloves or discharge static voltage by touching a grounded metal object.
Another important element is the defrost sensor. It is located in the defrost heater area and ensures that the ice on the evaporator is completely melted without the heater overheating. Its location is strictly tied to the evaporator unit, which in most LG models is hidden behind the back wall of the freezer.
Access to the thermostat in Side-by-Side refrigerators
Side-by-Side refrigerators from LG have a more complex architecture for the arrangement of control elements. Here, the thermostatic equipment is often concentrated in the upper technical compartment or in the lower part of the unit, depending on the compressor model and control system. Mechanical thermostats in such giants are extremely rare, giving way to multi-zone electronic systems.
If your Side-by-Side does use a mechanical regulator (which is typical for older or budget models), it is most likely located behind the top panel of the refrigerator compartment. To access it, you may need to remove the top decorative cornice, which is sometimes secured with hidden latches and screws under the caps. Be careful with plastic elements - they can be fragile.
In electronic versions, temperature sensors are placed strategically: one controls the freshness zone, another controls the freezer compartment, and the third controls the quick freezing zone. Often the main control unit, where signals from all sensors flow, is located in the upper right or left part of the refrigerator (rear). This is where the “brain” is located that makes the decision to turn on the compressor.
☑️ Preparing to search for a thermostat
Particular attention should be paid to models with a display on the door. In them, the control module can be integrated directly into the door panel, and the sensors are distributed among the cameras. Replacing elements in such cases requires careful removal of door trims and work with cables, which increases the risk of damage to the electronics.
Table: Location of elements depending on the type of system
To quickly navigate the design of your device, use the following table. It will help you narrow down your search and understand what tools you may need to access thermostat.
| System type | Location of the main sensor/thermostat | Difficulty of access | Required tool |
|---|---|---|---|
| Mechanics (single-chamber) | Inside the chamber, behind the ceiling or on the ceiling | Low | Phillips screwdriver |
| Mechanics (No Frost) | Behind the back wall or in the air duct | Medium | Screwdriver, ice pick |
| Electronics (standard) | Air duct, evaporator, technical. compartment | High | Screwdriver set, multimeter |
| Side-by-Side | Top tech. compartment or behind the panels | High | Screwdriver, keys |
As can be seen from the table, the difficulty of access directly depends on the generation of the refrigerator. If in old models everything was solved by removing one cover, then modern units require deep diagnostics and partial disassembly.
Do not forget that electronic systems often require not just physical replacement, but also setting parameters or resetting errors through the service menu. Without the appropriate equipment and knowledge, interfering with the electronics can lead to failure main board (main board).
Diagnostics: how to check the serviceability of the thermostat
Before looking for where the thermostat is located, much less changing it, you need to make sure that the problem lies there. Symptoms of a malfunction may be similar to a compressor failure or a freon leak. The main signs of thermostat failure are continuous operation of the compressor without shutdowns or complete silence of the unit when the plug is plugged into the socket.
The easiest way to check a mechanical thermostat is to test the contacts with a multimeter. To do this, you need to get to the thermostat terminal box, disconnect the wires and measure the resistance. At room temperature, the contacts should be closed (resistance is close to zero), and when the sensor is placed in the cold (for example, in a freezer for 10-15 minutes), they should open.
- 🔍 Visual inspection: check the contacts for the presence of soot, oxidation or melting of the insulation.
- ❄️ Cold test: put the sensitive part of the thermostat in the freezer and listen for a click (for mechanics).
- ⚡ Resistance measurement: use a multimeter in continuity mode to check the continuity of the circuit.
For electronic sensors, testing is carried out by measuring their resistance at different temperatures and comparing the readings with a table of ratings for a specific LG model. A deviation from the norm of even 10-15% may indicate a malfunction of the element that transmits incorrect data to the control board.
Step-by-step instructions for replacement thermostat
If the diagnostics confirm a malfunction, proceed with replacement. This process requires care and consistency of actions. Remember that incorrect installation can lead to repeated breakdowns or incorrect operation of the refrigerator.
First, you must completely disconnect the unit and defrost it if access to the thermostat requires removing panels inside the chamber. Ice and water can damage electrical contacts. After defrosting, remove all interfering elements: shelves, drawers, decorative trims and protective covers.
⚠️ Attention: The capillary tube of a mechanical thermostat is very thin and breaks easily. When installing a new element, avoid sharp bends and creases in the tube, otherwise the refrigerant inside it will come out and the thermostat will stop working.
Remove the old thermostat, having previously photographed the wiring diagram. This is a critical point, as mixed-up contacts can cause a short circuit. Install the new element, secure the capillary tube in the same position as the old one (use standard clips and seats), and assemble the structure in the reverse order.
After assembly, turn on the refrigerator and check its operation for several hours. The temperature should stabilize, and the cycles of turning on and off the compressor should become uniform. If the result is not achieved, perhaps the problem lies deeper or the new thermostat is also defective.
What to do if a new thermostat is not on sale?
You can temporarily use a thermostat from another refrigerator with similar characteristics, but you will need to adjust the length of the capillary tube and adjust the temperature range. However, this is a temporary solution, and it is better to wait for the original spare part.
Frequently asked questions (FAQ)
Is it possible to operate an LG refrigerator without a thermostat?
Theoretically, it is possible if you force the contacts to close, but this will lead to continuous operation of the compressor. As a result, the food in the refrigerator compartment will freeze, and the motor-compressor will quickly overheat and burn out due to the lack of rest cycles. Operation without a working thermostat is unacceptable.
Why does the LG refrigerator not turn off after replacing the thermostat?
There may be several reasons: the temperature range of the new thermostat is incorrectly selected, the capillary tube is installed incorrectly (does not fit tightly enough to the evaporator), or the problem is not in the thermostat at all (for example, a freon leak or compressor malfunction).
Where to buy an original thermostat for LG?
Original spare parts are best purchased from authorized LG service centers or specialized spare parts stores for household appliances, indicating the exact model of your refrigerator (the model is indicated on the nameplate inside the chamber).
How to understand what Is it the sensor that is faulty, and not the control board?
If, when checking, the sensor shows resistance corresponding to the temperature (or an open/short circuit), and the board continues to give an error or does not control the compressor correctly, most likely the problem is in the board. Accurate diagnostics of electronics requires an oscilloscope and professional knowledge.