Modern refrigerators Samsung equipped with sophisticated electronics that monitor each cycle of the compressor. The key element of this system is thermal sensor (or thermistor), which constantly measures the temperature in the chambers and sends data to the main board. If this small component fails, the unit ceases to maintain cold correctly, which can lead to spoilage of food or defrosting of the entire contents.
Owners often notice strange behavior of the equipment: the refrigerator hums without interruption, the freezer turns into an ice block, or, conversely, it becomes too warm inside. In 90% of cases, such symptoms indicate incorrect readings of the thermistor or its complete break. Before calling a technician, it is important to carry out an initial diagnosis to understand whether the problem is really in the sensor or the cause lies deeper.
In this article we will look in detail at how to find, remove and check the serviceability of the temperature sensor on the refrigerator Samsung using a conventional multimeter. You will learn about typical resistances, error codes and replacement nuances that will help save time and budget on repairs.
Fault symptoms and error codes
The first sign that thermal sensor transmits incorrect data is chaotic behavior of the compressor. The electronics receive a false signal that the temperature in the chamber is higher than normal and causes the motor to run continuously. This leads to increased energy consumption and freezing of the rear wall of the refrigerator compartment.
Models Samsung with a digital display (series RB, RS, RL) when a problem is detected, the corresponding error code is immediately displayed on the screen. This greatly simplifies diagnostics, since you know exactly which circuit is failing. The most common codes associated with temperature sensors:
- ❄️ 21C / 22C — error in the refrigerator compartment temperature sensor (main).
- ❄️ 23C / 24C — malfunction of the refrigerator compartment evaporator sensor.
- ❄️ 25C / 26C — problems with the freezer compartment sensor.
- ❄️ 41C / 42C —defroster error (defrost) in the freezer.
If all indicators are flashing on the display or a combination is displayed 88 88, this may indicate a power surge that has damaged the control board, but sometimes this is how the system reacts to a sudden change in resistance readings in the thermistor circuit.
⚠️ Attention: If your refrigerator is not equipped display, you can determine the error code by the blinking of the “Cold” or “Super Freeze” indicators. The number of blinks corresponds to a specific unit, the explanation of which can be found in the service manual of a specific model.
It is also worth paying attention to the physical condition of the products. If the meat in the freezer is covered with a thick crust of ice, and in the refrigerator compartment vegetables begin to rot due to high humidity and heat, this is a sure sign that the defrosting cycle does not start or, on the contrary, starts too often.
Location of sensors in different models
In refrigerators Samsung s system No Frost usually installs from two to four temperature sensors. Their location depends on the specific modification and year of manufacture of the device. The main number of them is concentrated in the area of the evaporator, hidden behind a plastic panel.
The refrigeration chamber sensor is most often located in the upper part of the rear wall, sometimes it is built into the plastic casing of the air duct. The freezer and evaporator sensors are always hidden deep inside, under the casing, to accurately read the temperature of the circulating air and the condition of the radiator.
Where to look for the sensor in two-chamber models?
In two-chamber Samsung models, the main refrigerator compartment sensor is often mounted on a bracket behind the top shelf. To get to it, you need to remove the lampshade and the top cover. The evaporator sensor is located behind the back panel of the freezer, which must be completely defrosted before removal.
You will need to partially disassemble the unit to access most sensors. This includes removing shelves, drawers, lamp shades and protective plastic panels. It is important to act carefully, as plastic latches become fragile in the cold.
- 🔍 Upper sensor: located in the ceiling of the refrigerator compartment, often under a decorative trim.
- 🔍 Bottom sensor: located in a niche under the lower drawer for vegetables, controls the temperature in the lower zone.
- 🔍 Evaporator sensor: attached directly to the aluminum fins of the radiator behind the rear wall.
Before starting any disassembly work, be sure to disconnect the refrigerator from the power supply. Working with live electrical wiring and electronic components is prohibited and life-threatening.
Necessary tools and preparation
For high-quality diagnostics, you do not need complex industrial equipment. A standard DIY kit and one specialized device are enough. The main requirement is the accuracy of measurements, since a resistance deviation of even a few kOhms can lead to incorrect operation of the entire system.
You will need a digital multimeter (tester) with the ability to measure resistance in the range from 1 kOhm to 100 kOhm. It is not recommended to use analog pointer instruments due to low accuracy and the possibility of damaging sensitive electronics by incorrectly selecting the mode.
☑️ Preparation for diagnostics
Also prepare a set of screwdrivers (phillips and flat), a hair dryer (for carefully removing plastic panels, if they frozen) and a container for collecting melt water. Disassembly often requires complete defrosting, since access to the evaporator sensor is blocked by an ice crust.
Do not forget about the heat source for testing. To check whether the resistance of the sensor changes depending on temperature, you will need to warm it in your hands or immerse it in warm water. Prepare a glass of water at room temperature or slightly higher in advance.
The testing algorithm with a multimeter
The testing process thermistor is based on measuring its electrical resistance. A working sensor is a semiconductor device whose resistance changes with temperature changes. If the device shows infinity (open) or zero (short circuit) regardless of temperature, the part is faulty.
First remove the sensor from its seat by disconnecting the connector. Set the multimeter to resistance (Ohm) measurement mode, selecting a limit of 20 kOhm or 200 kOhm, depending on the rating of your sensor (usually 5 kOhm, 10 kOhm, or 50 kOhm at 25°C).
Connect the multimeter probes to the sensor connector pins. Polarity is not important in this case, since thermistors do not have a plus or minus. Record the readings on the device screen at room temperature.
Next, you need to check the sensor’s response to heating. You can gently blow on it with a hairdryer (not hot air, so as not to melt the plastic) or immerse it in warm water, after insulating the contacts if they are open. The resistance should change abruptly or smoothly, depending on the type of thermistor (NTC or PTC).
For refrigerators Samsung negative temperature coefficient (NTC) thermistors are most often used. This means that when heated, their resistance decreases, and when cooled, it increases. If you observe an inverse relationship or lack of response, the component is defective.
Table of normal resistance values
To accurately determine serviceability, it is not enough just to see the changing numbers. It is necessary to compare them with the reference values for a specific thermistor model. In refrigerators Samsung the most common sensors are with nominal resistances of 5 kOhm, 10 kOhm and 50 kOhm at a temperature of +25°C.
Below is a table of indicative values for a standard 50 kOhm sensor, which is often used in modern models. Please note that the values may vary slightly depending on the manufacturer of the sensor itself (for example, Sensor Temp or original spare parts Samsung).
| Temperature (°C) | Resistance (kOhm) for 50k | Resistance (kOhm) for 10k | Resistance (kOhm) for 5k |
|---|---|---|---|
| -20°C | ~260 kOhm | ~52 kOhm | ~26 kOhm |
| -10°C | ~150 kOhm | ~30 kOhm | ~15 kOhm |
| 0°C | ~90 kOhm | ~18 kOhm | ~9 kOhm |
| +25°C | ~50 kOhm | ~10 kOhm | ~5 kOhm |
| +50°C | ~20 kOhm | ~4 kOhm | ~2 kOhm |
If your measurements differ radically from the table data (for example, at 0°C a 50k sensor shows 5 kOhm), then the characteristic curve is broken. Such a sensor will “lie” to the controller, causing the refrigerator to freeze too much or too little.
Replacement and error reset
Once the fault is confirmed, the defective sensor must be replaced. Repairing old sensors by soldering or twisting wires is impractical, since the seal of the case will be broken, which will lead to oxidation of the contacts and repeated failure after a short time. time.
Install the new one thermistor into its original place, ensuring tight contact with the surface whose temperature it is to measure. Often the sensors are fixed with a special heat-conducting paste or simply inserted into the socket until it stops.
⚠️ Attention: After replacing the sensor, the error on the display may not disappear automatically. It is necessary to perform an error reset (Reset). To do this, unplug the refrigerator for 10-15 minutes. Some models require pressing the Cold and Super Freeze buttons simultaneously for 5-10 seconds.
In models without a display, reset. occurs automatically after several on-off cycles if the system does not detect deviations. However, if the error persists, the problem may lie not in the sensor, but in the wiring harnesses or the main control board itself.
Check the integrity of the wires coming from the sensor connector to the board. Often, in places where they bend or pass through the door hinges, the wires break, creating the effect of a break. which the multimeter diagnoses as a malfunction of the sensor itself.
Frequently asked questions (FAQ)
Is it possible to temporarily close the sensor contacts to make the refrigerator work?
Technically, it is possible to close the contacts, but this will lead to emergency operation of the refrigerator. that the temperature is very low, and the compressor will stop turning on, or, on the contrary, will work without stopping. This is dangerous for the compressor and the products.
Why does the new sensor not eliminate the error?
There may be several reasons: errors in the board memory have not been reset, the control board itself is faulty, the wiring is damaged, or a sensor with an inappropriate resistance value is installed (for example, 10k instead). 50k).
Where to buy an original sensor for Samsung?
Original spare parts are sold in authorized service centers and specialized stores of spare parts for household appliances. When purchasing, pay attention to the marking (Part Number), which must match the code on your old sensor.
Influences. Does the humidity in the chamber affect the sensor readings?
The sensor itself is sealed, but if the contacts in the connector are oxidized due to moisture, the circuit resistance will change. Always check the condition of the connectors and, if necessary, clean them with alcohol.