A failure in the cooling system often becomes an unpleasant surprise for owners of household appliances, especially when it comes to storing food. If your LG refrigerator no longer maintains the set temperature, constantly works or, conversely, turns off too often, the culprit may be a faulty thermostat. It is this small but critical component that controls the cycles of turning the compressor on and off, ensuring a stable microclimate inside the chambers.
Understanding that where is the thermostat locatedis the first step towards self-diagnosis and possible repair. The location of this element can vary significantly depending on the model of the unit, the year of its manufacture and the type of defrosting system (No Frost or drip). In some cases, to access it you will need to dismantle a significant part of the internal plastic, in others it is enough to remove one decorative trim.
In this article we will analyze in detail the architecture of LG refrigerators, indicate the exact locations of temperature sensors in various series and describe the algorithm of actions when a malfunction is detected. You will learn how to distinguish a mechanical regulator from an electronic sensor, what tools you will need for the job, and how to avoid common mistakes when disassembling the case.
The operating principle and types of thermostats in LG technology
Before you start your search thermostat, you need to understand what kind of device you are dealing with. In refrigeration equipment of the Korean brand LG, two main types of regulators have historically been used: mechanical and electronic. Mechanical models are a device with a capillary tube filled with freon or an inert gas, which responds to pressure changes due to temperature fluctuations.
Electronic analogues, which are more often found in modern models with a system No Frost and a display on the door, operate on the basis of thermistors. These compact sensors transmit an electrical signal to the main control board, which then decides to start the compressor. An error in determining the type of sensor can lead to the purchase of the wrong spare part and loss of time.
- 🔹 Mechanical thermostats are often marked TAM or K59 series and are visually identified by the presence of a long metal tube.
- 🔹 Electronic sensors are small plastic cylinders or tablets with two wires, built into evaporator or air channel.
- 🔹 In dual-compressor LG models, several independent sensors can be installed for each chamber separately.
It is important to note that mechanical regulators more often fail due to loss of tightness of the capillary system or sticking contacts, while electronic sensors suffer from oxidation of contacts or voltage surges in networks. Diagnostics each type requires its own approach and tools.
⚠️ Attention: Before starting any work to find or replace the thermostat, be sure to disconnect the LG refrigerator from the electrical network. Working with live electrical wiring and internal components is deadly.
Location of the thermostat in mechanically controlled refrigerators
If your unit is equipped with a rotary handle inside the refrigerator compartment, then you are dealing with a mechanical control system. In classic LG models, especially those released before the mid-2010s, thermostat most often hidden behind a plastic panel at the top of the refrigerator compartment. However, you won’t be able to simply remove the handle and get to the insides - the design requires careful disassembly.
Usually the thermostat body itself is attached to the back wall or ceiling of the chamber, and its sensitive capillary tube is led into the evaporator or pressed against the chamber wall for accurate temperature reading. In some LG series models GA or GC access to the adjusting screw and contact group is possible only after dismantling the top cover of the refrigerator and part of the internal plastic.
How to remove the regulator handle without damage?
The mechanical regulator handle often sits very tightly. Do not try to pry it off with a knife or screwdriver from the front side - the plastic may crack. The best method is to gently heat it with a hairdryer at low temperature for 30-40 seconds so that the plastic becomes more elastic, and then pull it straight towards you, grasping the base.
To access the mechanical unit, you will most likely need to remove the top decorative panel, which can be secured with hidden latches or screws under the plugs. After removing the panel, a view of the metal or plastic casing will open, inside of which the desired element is hidden. The capillary tube will run along the wall, often hidden in a groove or clamped with a metal bracket.
- 🔸 Look for the thermostat in the upper left or right corner of the refrigerator compartment, closer to the back wall.
- 🔸 Pay attention to the wires coming from the adjustment knob - they will lead you directly to the contact group.
- 🔸 In older models, access can be achieved by removing the entire top cover of the refrigerator from the outside.
Where to look for temperature sensors in models with a display (No Frost)
In modern LG refrigerators with a system No Frost and electronic control, the situation is radically different. There is no single “twist” inside the chamber, and temperature control is carried out by a network of sensors scattered across various units of the unit. The main element responsible for the temperature in the refrigerator compartment is a sensor located directly on the evaporator or in the cold air supply channel.
To get to this sensor, in most cases you will need to completely defrost the refrigerator within 10-12 hours and dismantle the rear panel inside the refrigerator compartment. It is behind this panel that the evaporator and fan are hidden. The sensor is usually inserted into a special hole in the aluminum fin of the evaporator and fixed with a small amount of sealant or a plastic holder.
In addition to the main refrigerator compartment sensor, the No Frost system may contain additional sensors: a defrost sensor (on the evaporator itself), a sensor in the freezer compartment and an ambient air sensor. Malfunction any of them can lead to erroneous readings on the display and incorrect operation of the compressor. For example, if the defrost sensor is lying, the refrigerator may not start the defrost mode, which will lead to ice fouling on the evaporator and stopping air circulation.
⚠️ Attention: When removing the back panel in No Frost refrigerators, be extremely careful. Plastic becomes brittle after prolonged use, and the mounting screws can be hidden under a layer of frost or decorative plugs. Do not use excessive force.
Instructions for dismantling and accessing the thermostat
The process of gaining access to thermostat requires consistency and accuracy. First you need to empty the refrigerator compartment of food and remove all shelves and drawers that interfere with work. Next, you should determine the type of fastening of the top panel or rear wall. LG models often use hidden-head screws covered with white plastic plugs, which can easily be mistaken for part of the design.
After removing the outer panels, you will see wiring harnesses and insulating materials. Thermoregulator can be mounted on a metal bracket or inserted into a plastic one groove To remove the mechanical thermostat, you need to carefully disconnect the capillary tube from the attachment point, being careful not to bend it or break the seal. The electronic sensor is simply removed from the socket, but first you need to disconnect the connector chip.
☑️ Checklist before disassembly
Pay special attention to marking the wires before disconnecting them. Even if the wire colors seem unique, it is better to play it safe and take a photo or make notes with a marker. This will save time during reassembly and eliminate the risk of short circuits. In some cases, the wires may be melted or oxidized, which also indicates possible problems in the power circuit.
Diagnostics and checking the serviceability of the thermostat
After removing the device, the question arises: how to understand that it is faulty? For mechanical thermostats, the most accurate method is a “continuity” test using a multimeter. At room temperature, the contacts should be closed (if it is a normally closed thermostat), and when cooled (for example, if you put it in the freezer for 15 minutes), they should open. Lack of response indicates a breakdown.
Electronic sensors are checked by measuring their resistance. Each type of sensor has its own resistance ratings at a certain temperature, which can be found in the technical documentation or compliance tables for LG. If the resistance is infinitely high (open) or zero (short circuit), the sensor definitely requires replacement. It is also worth visually inspecting the wires for fractures.
| Fault type | Symptom in LG refrigerator | Verification method | Result in case of breakdown |
|:--- |:--- |:--- |--- |
| Contacts sticking | The compressor runs non-stop | Testing with a multimeter | The circuit does not open when cooling |
| Open circuit | Refrigerator won't turn on | Resistance measurement | Infinite resistance |
| Loss of tightness | Poor cooling, frequent cycling | Visual inspection of the tube | Cracks, traces of oil, swelling |
| Electronics failure | Error on display, incorrect t° | Resistance measurement | The values do not correspond to the table |
It is worth considering that in some cases the problem may lie not in the thermostat itself, but in the wiring or control board. If replacing the sensor does not help, the contacts in the connector may have oxidized or the control module may have failed. In such cases, a deeper diagnosis electrical circuit of the unit is required.
Replacing the thermostat and setting the temperature
The replacement process begins with purchasing the correct analogue. For mechanical thermostats, the length of the capillary tube and the location of the contacts are important. For LG electronic sensors - resistance and connector type. Installation of a new element is carried out in the reverse order of removal. The mechanical tube must be placed exactly in the same groove and secured with a bracket, otherwise the temperature readings will be incorrect.
After assembling all the panels and connecting the wires, the refrigerator can be plugged into the network. The initial launch may take several hours to get up to speed. If you have a mechanical model, you will need to manually adjust the position of the handle. Typically, the middle position corresponds to a temperature of +4...+5°C in the refrigerator compartment. The adjustment should be carried out gradually, taking measurements with a thermometer.
⚠️ Attention: Technical characteristics and location of components may vary slightly depending on the specific modification of the LG refrigerator. Always check the technical documentation (service manual) for your model before starting work, since the design may change from batch to batch.
Frequently asked questions (FAQ)
Is it possible to temporarily close the thermostat contacts to make the refrigerator work?
Technically, you can close the contacts of a mechanical thermostat, and the compressor will start work continuously. However, this is a temporary measure and will result in deep freezing of food and possible damage to the compressor due to lack of rest cycles. This method can only be used for short-term testing or emergency cooling, but not for permanent operation.
Why does the new thermostat not fit the length of the tube?
The length of the capillary tube is a critical parameter. If the tube is too long, it can be carefully rolled into a ring (without bending!) and placed in the free space inside the case. If it is too short, the thermostat may not reach the sensitivity zone, and the refrigerator will not work correctly. In this case, it is better to look for a model with a suitable length or use an extension cord (for experienced craftsmen).
How often do you need to change the thermostat in an LG refrigerator?
The service life of the thermostat is not strictly limited in time and depends on the intensity of use and the quality of the electrical network. On average, mechanical thermostats last 5-7 years, electronic sensors can last 10 years or more. Replacement is required only if signs of a malfunction appear: incorrect temperature, continuous operation of the compressor, or complete failure to turn on.
What to do if, after replacement, the refrigerator begins to freeze very much?
Most likely, adjustment is required. Mechanical thermostats often have an adjustment screw under the seal or inside the housing. Turning the screw clockwise usually increases the shutdown temperature (the refrigerator will turn off earlier), counterclockwise - lowers it. Be careful: one turn of the screw can change the temperature by several degrees.