A failure in the cooling system often becomes an unpleasant surprise for the owner of modern household appliances. If you notice that the food in the chamber has begun to deteriorate faster than usual or, conversely, to freeze, the first suspect usually becomes LG refrigerator temperature sensor. This small but critical element is responsible for transmitting data about the climate inside the chamber to the main control module.
Understanding this where is the temperature sensor of the LG refrigeratoris necessary not only for professional craftsmen, but also for those who are accustomed to performing minor repairs with their own hands. The design of the units of the South Korean brand has its own characteristics, and the location of the sensors may vary depending on the model and type of defrosting. In this article we will analyze in detail the architecture of the thermoregulation system.
Accurate diagnostics is impossible without knowledge of the design of your device. Thermistor (this is the technically correct name of the sensor) is a resistor whose resistance changes depending on the heat of the environment. Its incorrect operation leads to the compressor running either too long or not turning on at all. Let's figure out how to find this element in different types of refrigerators.
The principle of operation of the thermostat in No Frost systems
In refrigerators with a system No Frost air circulation occurs forcibly, and temperature control here is carried out especially carefully. The sensor in such models is most often located inside the evaporator, hidden behind a plastic panel on the back wall of the freezer. It is here that the air masses are cooled before they are supplied to the main compartment.
Access to the area where it is located cooling sensorrequires partial disassembly of the inside of the freezer. You will have to remove the shelves, drawers and remove the back panel. Underneath it you will find an evaporator and a thermistor attached to it or in its immediate vicinity. It can be built into a special groove or attached to the evaporator tube using a clamp.
⚠️ Attention: When removing the back panel in the freezer, be extremely careful with the plastic latches. Plastic becomes brittle in the cold, and one awkward movement can lead to breakage of the case.
In some LG models, especially in lines with the function Door Cooling+, an additional sensor can be installed in the upper part of the refrigerator compartment to control the air flow from the door. This complicates the design, but increases the accuracy of maintaining the mode.
Why do sensors fail?
The main reason for the failure of thermistors in LG refrigerators is the cyclic freezing and thawing of condensate that penetrates inside the sensor housing. Moisture oxidizes the contacts, which leads to a change in resistance and transmission of incorrect data to the control board.
The location of the sensor in models with drip defrosting
The situation with searching for a sensor in refrigerators with a direct or drip defrosting system (Direct Cool) looks different. Here thermostat most often it is located in the refrigerator compartment. In classic models, it can be built into the thermostat, which looks like a rotary knob, but modern electronic versions from LG use a separate electronic sensor.
Where exactly to look? In most cases temperature sensor attached to the inner wall of the refrigerator compartment, often in the upper part, closer to the lampshade or ventilation hole. It looks like a small plastic tip hanging on a wire or mounted in the wall.
If your model uses a mechanical thermostat, then the sensitive element itself (bellows tube) passes inside the housing and is pressed against the evaporator. Replacing such an element requires a deeper intervention than simply replacing an electronic thermistor.
Sensors in dual-circuit cooling systems
Modern premium LG models are often equipped with two independent cooling circuits. This means that separate evaporators and, accordingly, separate temperature sensorsoperate in the freezer and refrigerator compartments. In such systems, one sensor controls freezing, and the second controls the climate in the upper compartment.
Troubleshooting in such units requires checking both elements. If an LG refrigerator shows a temperature-related error, the control module usually indicates which circuit is not working correctly. The freezer sensor in dual-circuit systems is often hidden behind the duct panel.
It is important to understand that in dual-circuit systems, the failure of one sensor can block the operation of the entire unit or a specific circuit. The protection system prevents the compressor from overheating or food from defrosting when incorrect data is received.
Typical symptoms of a thermistor malfunction
How to understand that the problem lies in the sensor and not in the compressor or freon leak? The electronics of an LG refrigerator, when receiving incorrect data from the thermistor, often displays a specific error code on the display or by blinking indicators. However, there are also visual signs.
If thermistor “lies” and shows the module that the chamber is warmer than it actually is, the compressor will work without stopping. This leads to the formation of a “fur coat” and freezing of food. If the sensor shows false hypothermia, the unit may be idle for a long time, and the products will begin to deteriorate.
List of main symptoms of a malfunction:
- ❄️ The display shows an error code associated with the temperature sensor (for example, rF, rS, dS).
- ⏱️ The compressor operates in cycles that do not correspond to the settings (too often or too rarely).
- 🌡️ The actual temperature in the chamber is very different from the one set by the user.
- 🔌 The refrigerator spontaneously turns on and off at short intervals.
Sometimes a sensor malfunction can be disguised as other problems. For example, if the evaporator freezes, this may be due to the fact that the defrost sensor did not respond in time. Therefore, comprehensive diagnostics is important.
Table of error codes and corresponding sensors
Diagnostics of LG refrigerators is greatly simplified thanks to the self-diagnosis system. The control module displays error codes that directly indicate the problem node. Below is a table with the most common codes associated with temperature sensors.
| Error code | Problem description | Affected element | Probable cause |
|---|---|---|---|
rF |
Refrigeration sensor error cameras | Thermistor (Fridge) | Open circuit or short circuit |
rS |
Evaporator sensor error | Evaporator sensor | Incorrect readings resistance |
dS |
Door sensor error (Door Cooling) | Door channel sensor | Damage to the wiring in the door hinge |
Er SF |
Freezer sensor error | Freezer thermistor | Oxidation of contacts |
It is worth noting that the codes may vary slightly depending on the series and year of manufacture of your LG refrigerator. Always check the technical documentation of a specific model if standard codes do not produce results.
⚠️ Attention: The appearance of an error code does not always mean a physical breakdown of the sensor. Sometimes the problem lies in oxidation of the contacts on the connector or damage to the cable going to the control board.
Instructions for checking and replacing the sensor
If you determine that temperature sensor requires replacement, you will need a multimeter to check the resistance. The replacement process varies, but the general algorithm is as follows. First you need to gain access to the sensor by removing the necessary panels.
After removing the sensor, disconnect the connector. In resistance (ohms) mode, check the multimeter readings. At room temperature, the resistance of a working LG thermistor is usually about 5-10 kOhm (the exact value depends on the model). When heating in your hands, the resistance should drop, and when cooling, it should increase.
Checklist of actions when replacing:
- 🔧 Turn off the power to the refrigerator and defrost the chambers.
- 🔍 Remove the back panel in the freezer or refrigerator camera.
- 🔌 Disconnect the sensor connector and remove it from the seat.
- 🛠️ Install a new original sensor and connect the connector until it clicks.
☑️ Preparation for diagnostics
After installing the new element, reassemble the structure in the reverse order and turn on the refrigerator. The error should disappear after a few minutes of operation, or after a reboot (disconnect from the network for 10-15 minutes).
Frequently asked questions (FAQ)
Is it possible to temporarily short-circuit the sensor to make the refrigerator work?
Technically, shorting the sensor or installing a fixed resistor can start the compressor. However, this is extremely dangerous: the refrigerator will lose the ability to regulate temperature, which will lead either to defrosting of food or to freezing of the evaporator and breakdown of the compressor. This can only be done for a few minutes for diagnostics.
Where to buy an original temperature sensor for LG?
Original spare parts are best ordered from authorized LG service centers or specialized spare parts stores for household appliances, indicating the exact model (P/N) of your refrigerator. Analogs from Chinese sites may have a different resistance, which will lead to incorrect operation.
Why does the error not disappear after replacing the sensor?
If the new sensor is working, but the error persists, the problem may be in the control board, broken wiring inside the case, or oxidation of the connector contacts. It may also be necessary to reset errors through the service menu or completely turn off the power for a long time.
Does the temperature in the room affect the operation of the sensor?
Yes, if the refrigerator is in an unheated room at a temperature below +10°C, the thermostat (in mechanical models) or the logic of the board may not give the command to turn on the compressor, since they believe that there is already quite cold. Electronic sensors inside the chamber have less influence on this, but the overall climate is important.