Modern two-chamber refrigerators Atlant with system No Frost or full automatic defrosting are complex electronic devices. They are designed with multiple sensors that continuously read the temperature in different areas of the chamber and evaporator. If one of these elements fails, the compressor may stop starting or, conversely, work without interruption, which leads to spoilage of products.
The main task of the user at the first sign of a malfunction is to correctly identify the problem. Often, a failure of the sensor is mistaken for a malfunction of the control board or a violation of the tightness of the circuit. However, it is thermal sensors (thermistors) that are the most common cause of error codes appearing on the display or chaotic blinking of indicators.
In this article we will look in detail at where the sensors are located in different models Atlant, how to check them with a multimeter and what to look for when visual inspection. Correct diagnostics will allow you to avoid purchasing unnecessary spare parts and save on calling a technician.
Operation principle and types of temperature sensors
Belarusian-made refrigeration equipment uses thermistors with a negative temperature coefficient of resistance (NTC). This means that when the temperature decreases, their electrical resistance increases, and when heated, it decreases. The control unit electronics constantly monitors these changes and, based on the data received, makes a decision to turn the compressor on or off.
The number of sensors depends on the specific model of the refrigerator Atlant. In simple models, there may be only one sensor in the refrigerator compartment. In more advanced versions with the system No Frost their number can reach four or more pieces. They control not only the air in the chambers, but also the temperature of the evaporator for the correct operation of the defrosting system.
⚠️ Attention: Never try to check the operation of the sensor by heating it with an open fire or immersing it in boiling water. A sudden change in temperature can destroy the sensing element, and even a working part will become unusable.
The most common locations for installing sensors include the evaporator area of the freezer, the air duct between the chambers and the interior of the refrigerator compartment. Each of them is responsible for its own section of the cooling cycle, and the failure of any of them disrupts the entire operation algorithm of the unit.
Fault symptoms and error codes
You can understand that checking the sensors on the refrigerator Atlant is necessary by indirect signs even before disassembling the unit. The electronics simulate the behavior of the system and, when receiving incorrect data (for example, an open circuit or short circuit), goes into emergency mode. At this moment, indicators may light up on the front panel or a digital code may appear.
The most obvious symptom is the constant operation of the compressor. If thermostat or the sensor is “stuck” in the low temperature position, the brain of the refrigerator thinks that it is warm inside and drives the motor without stopping. The opposite situation is also possible: the unit is silent when it should be freezing, because the sensor erroneously reports that the target values have been reached.
- 🔥 The error code is displayed on the display
F1,F2,F3orF4(the decoding depends on the series). - ❄️ The refrigerator compartment is too warm, although there is ice in the freezer, or vice versa.
- 🔊 The compressor makes sounds of frequent switching on and off (clocking).
- 💧 A “fur coat” forms on the back wall of the refrigerator compartment or, conversely, it is completely dry when running motor.
It is important to note that error codes may differ for electronically and mechanically controlled refrigerators. In models with a display, information is displayed digitally, while in budget series the problem is indicated by a flashing temperature light or a sound signal.
Location of sensors in different models
To check the temperature sensor, you first need to find it. In refrigerators Atlant with the system No Frost access to the evaporator sensor is usually hidden behind a plastic panel on the back wall of the freezer. To gain access, you will have to remove the shelves, drawers and unscrew the fastening screws.
The air sensor in the refrigerator compartment is most often hidden in a special plastic casing on the side or rear wall. In some models it is integrated into the control unit, which is located in the upper part of the case. The exact location depends on the design features of the specific series.
Where to look for a defrost sensor?
The defrost sensor is almost always attached directly to the evaporator tubes. It can be inserted into a special socket or attached with a metal bracket. Visually, this is a small cylinder, similar to a bullet, from which two wires come.
Be careful when dismantling plastic panels. Plastic becomes brittle in the cold, and careless movement can lead to breakage of the latches. It is recommended to let the refrigerator stand unplugged for at least 30-40 minutes so that the plastic warms up a little and becomes more elastic.
Instructions for testing with a multimeter
The most reliable diagnostic method is to measure electrical resistance using a multimeter. To carry out the test, the device must be switched to resistance measurement mode (Ohm), selecting a limit of 20 kOhm. Before starting measurements, make sure that the probe wires are in good condition and show zero when closed.
The verification process consists of comparing the actual multimeter readings with the reference values for a given temperature. Since the sensor changes resistance depending on the heat, simply “ringing” it for a short circuit is not enough. It is necessary to evaluate whether it reacts to changes in temperature.
☑️ Algorithm for checking with a multimeter
If the multimeter shows one at the limit of 20 kOhm (infinity), then it is in the sensor circuit break. If the meter reads zero or close to zero at room temperature, there is likely a short circuit inside the sensor. In both cases, the part requires replacement.
For more accurate diagnostics, you can place the sensor in a container with water of a known temperature (for example, room +20°C or from a refrigerator +5°C) and measure the resistance. A sharp change in readings when immersed in water indicates the tightness of the housing and the operability of the sensitive element.
⚠️ Attention: Technical characteristics and resistance ratings may vary depending on the year of manufacture and modification of the control board. Always check the data obtained with the official documentation for your specific model Atlant.
Table of resistances and temperature values
To correctly assess the condition of the thermistor, you need to know its nominal resistance at a certain temperature. In refrigerators Atlant most often sensors with a rating of 6 kOhm or 10 kOhm are used at a temperature of +25°C. Below is a reference table for a standard NTC thermistor.
| Environment temperature, °C | Resistance, kOhm (approx.) | Circuit condition |
|---|---|---|
| +25 (Room) | 6.0 - 10.0 | Normal |
| +10 (Refrigerator) | 15.0 - 20.0 | Normal |
| 0 (Freezing point) | 25.0 - 30.0 | Normal |
| -18 (Freezer) | 80.0 - 100.0 | Normal |
| Any | 0 or ∞ | Fault |
Please note that the values in the table are averaged. Actual figures may vary between 5-10%. The main thing is the smoothness of the resistance change. If the readings on the multimeter do not change when the sensor is cooled with fingers or ice, then the element is defective.
Frequent errors during diagnostics and replacement
One of the common mistakes is ignoring the condition of the wiring. Often the sensor itself is intact, but the wire is frayed at the point where it exits the housing or in the area of the door hinge. Before purchasing a new spare part, be sure to “ring” the circuit from the connector to the sensor itself.
Also, amateur craftsmen often forget about sealing. The junction of the new sensor with the wires must be carefully insulated, preferably using heat shrink and sealant. Moisture getting inside the connection will lead to oxidation of the contacts and repeated failure in a short time.
- 🚫 Using ordinary electrical tape, which dries out over time in the cold.
- 🚫 Installing a sensor with a different resistance value (for example, 10 kOhm instead of 6 kOhm).
- 🚫 Ignoring checking the connector on the control board (oxidation of contacts).
If, after replacing the sensor, the refrigerator Atlant continues to give an error, the problem may lie in the control unit itself. In rare cases, the resistor on the board, which is responsible for reading readings from the thermistor, burns out. In such a situation, professional electronics repair is required.
Is it possible to temporarily short-circuit the sensor?
Some users try to short-circuit the sensor in order to deceive the system. This is strictly not recommended. The control unit will go into emergency mode, and the refrigerator will either stop freezing or will work continuously, which will lead to freezing of the evaporator and breakdown of the compressor.
FAQ: Frequently asked questions
Is it possible to replace the sensor with an analogue one with a different resistance?
It is extremely undesirable. The control unit Atlant is programmed for a certain resistance range. Installing a sensor with a different rating will lead to incorrect temperature readings, and the refrigerator will work with errors or will not start at all.
Why does error F1 light up if the sensor is intact?
Code F1 usually indicates a malfunction in the air temperature sensor circuit. If the sensor itself is working, check the integrity of the wires leading to it and the condition of the connector on the board. Also, the problem may be in oxidized contacts.
How to understand which sensor is faulty if there are several of them?
In models with a display, the error code often indicates a specific sensor (for example, F1 - air, F2 - evaporator). In models without a display, you will have to use a multimeter to call all available sensors in turn, comparing their readings with the table of ratings.
Does it need to defrost the refrigerator before replacing the sensor?
Yes, if the sensor is located on the evaporator. You will have to remove the back panel in the freezer and there may be ice in there. Complete defrosting (at least 10-12 hours) will simplify access and prevent damage to plastic parts during dismantling.