The question about the number of thermostats in Atlant refrigerators arises among owners most often in two cases: when the equipment stops freezing or when a failed element needs to be replaced. The answer to this cannot be unambiguous without reference to a specific model, since the Belarusian manufacturer produces a wide range of equipment, from budget single-compressor systems to complex two-chamber units with the No Frost system.
Understanding what how many thermostats are in the Atlant refrigerator is installed in your specific case is key for correct diagnosis of faults. The erroneous opinion that there is one sensor where there are two can lead to unnecessary costs for spare parts and time during repairs. In this article, we will analyze in detail the design of thermoregulatory systems of various series, explain the difference between mechanical thermostats and electronic sensors, and also help determine the number of regulators in your model.
We should immediately note that classic models with a drip defrosting system are most often equipped with one main thermostat that controls compressor. However, more complex designs, especially those that have the “Super Freeze” function or a separate chamber for storing vegetables, may have additional automation. Let's dive into the technical details of the design of these units.
Classification of temperature control systems in Atlant
All refrigerators of the brand Atlant can be divided into two large groups according to the type of temperature control: mechanical and electronic. In mechanical systems, the main element is the thermostat - a device that opens and closes the electrical circuit depending on the temperature in the evaporator or refrigerator compartment. In such models, the number of thermostats is usually minimal and corresponds to the number of compressors, if specific functions are not taken into account.
In electronic models, the role of a mechanical thermostat is performed by temperature sensors (thermistors), which transmit data to the electronic control module. Here the question “how many thermostats” is transformed into the question about the number of sensors. There can be significantly more of them, since they control not only the operation of the compressor, but also the temperature in each zone, the operation of fans and the defrost system.
⚠️ Attention: When self-diagnosis, it is important not to confuse a mechanical thermostat (K-59, TAM-112 and analogues) with a defrost sensor or evaporator temperature sensor. They may look similar, but have different resistances and operating principles.
To accurately determine the type of control system you have, you need to look at the technical data sheet or inspect the control panel. If the front panel has a digital display and buttons for setting degrees, you have an electronic system. If there is a “twist” hanging inside the refrigeration chamber with marks from 1 to 7, then this is a mechanical control.
The number of control elements directly depends on the complexity of the design. Simple models, such as series MXM 1700 or MXM 1800, have the simplest circuit. More advanced series, for example 4500th or 6000th series, may have additional control loops to maintain optimal humidity and temperature zones.
What is the difference between a thermostat and a thermostat?
In everyday life, these terms are often used as synonyms, but technically a thermostat is a mechanical device with a bellows filled with freon that physically opens the contacts. Thermostat is a more general term that can include both electronic control units and mechanical relays. In the context of repairing Atlant refrigerators, a “thermostat” most often means a mechanical thermostat.
Single-compressor models: standard design
The most common group of Atlant refrigerators are two-chamber units with one compressor and a drip defrosting system. In such models, as a rule, one thermostatis installed. It is located inside the refrigerator compartment and controls the air temperature in this compartment. When the temperature reaches the set value, the thermostat opens the circuit and the compressor turns off.
The defrosting of the evaporator in the freezer occurs passively, while the compressor is stopped. Thawed water flows into a tray on the compressor. In this scheme, a second thermostat is not required, since the temperature in the freezer directly depends on the operating time of the compressor, which is set by the settings of the main thermostat in the refrigerator compartment.
However, there is a nuance associated with the “Super Freeze” function. In some modifications, to implement this function, an additional switch may be used, which forcibly turns on the heating element or changes the logic of operation, but this is not a full-fledged second thermostat in the classical sense. This is rather an additional contact in the control circuit.
Typical models with one thermostat:
- 🧊 Atlant MXM 1700, 1701, 1702 - classic scheme with one mechanical thermostat.
- 🧊 Atlant MXM 1800, 1801, 1802 - similar design, one temperature regulator.
- 🧊 Atlant MXM 2800, 2808 - also equipped with one main thermostat.
- 🧊 Atlant MXM 4000 series (modifications) - basic versions have one mechanical regulator.
If your refrigerator stops turning off or, conversely, does not turn on, in 80% of cases the problem lies in this single thermostat. Replacing it is a standard procedure that does not require complex equipment, except for a set of screwdrivers and, possibly, a multimeter for checking.
Two-compressor refrigerators: independent control
The situation changes dramatically when we consider the Atlant two-compressor models. In such units, the refrigeration and freezer compartments have completely independent cooling circuits, each with its own compressor, condenser and own thermostat. Consequently, the Atlant two-compressor refrigerator always has its own thermostat two thermostats.
One thermostat is located in the refrigeration chamber and controls the upper compressor. The second thermostat is located in the freezer compartment (often behind a plastic panel or in a niche) and controls the bottom compressor. This allows you to set independent temperature conditions: for example, +4°C in the refrigerator and -18°C in the freezer, which cannot be implemented with high accuracy in single-compressor systems.
The presence of two thermostats increases the reliability of the system. If one compressor or one thermostat fails, the second chamber will continue to operate normally. This is an important advantage of dual-compressor circuits, although they consume more electricity and create more noise.
The location of the second thermostat in the freezer often causes difficulties for inexperienced craftsmen. It can be hidden behind the cover of the lighting lamp or built into the wall of the chamber. Access to it often requires partial disassembly of the interior of the freezer.
List of popular two-compressor models:
- ❄️ Atlant MHM 1732, 1733, 1734 - classic two-compressor models with two thermostats.
- ❄️ Atlant MKhM 1833, 1834, 1835 - also equipped with two independent control circuits.
- ❄️ Atlant MKhM 2034, 2035, 2036 - two-compressor circuit with two regulators.
- ❄️ Atlant MXM 6021, 6025 are modern models that retain the principle of two independent circuits.
⚠️ Attention: In two-compressor models, thermostats may differ in parameters (on/off temperature). Do not install a thermostat from the refrigerator to the freezer and vice versa - this will lead to incorrect operation of the equipment.
No Frost systems and electronic control
Atlant refrigerators with the system No Frost (or Partial No Frost) are the most complex category. In them, traditional mechanical thermostats are often replaced with electronic sensors (thermistors), the number of which can vary from 2 to 5 pieces depending on the functionality. Here it is no longer possible to simply say “one” or “two” regulators.
The typical No Frost circuit contains:
- 🌡️ Air temperature sensor in the refrigeration chamber (analogue of a thermostat).
- 🌡️ Evaporator temperature sensor (for defrosting control).
- 🌡️ Temperature sensor in the freezer (in some models).
- 🌡️ Defrost sensor (thermal fuse), which can be combined with the evaporator sensor.
The main difference is that in such systems there is no direct open circuit of the compressor thermostat. All signals are sent to the electronic control unit, which already makes the decision to turn on the compressor, fan or defrost heating element. Therefore, if your Atlanta has a display on the door, look not for the thermostat, but for the sensors.
A common problem in such models is the failure of the defrost sensor. If it is “lying”, the system may not start defrosting the evaporator, which will lead to the fouling of the evaporator with ice (“a fur coat”) and the cessation of cooling, even if the compressor is working properly.
Table of correspondence between models and number of regulators
For ease of diagnosis, we have compiled a summary table that will help you quickly determine how many thermostats should be in your Atlant model. Please note that there may be modifications within the same series, so visual inspection is always a priority.
| Series / Model | System type | Number of compressors | Number of thermostats (sensors) | Location |
|---|---|---|---|---|
| MHM 1700-1709 | Mechanics (Drip) | 1 | 1 | Refrigeration chamber (plafond) |
| MHM 1800-1809 | Mechanics (Drip) | 1 | 1 | Refrigeration chamber (plafond) |
| MHM 1730-1739 | Mechanics (Drip) | 2 | 2 | HK and Freezer |
| MXM 4000 (No Frost) | Electronics | 1 | 2-3 (sensors) | Evaporator and air channel |
| MXM 6021-6025 | Mechanics/Electronics | 2 | 2 (or 2+ sensors) | Independent circuits |
The table shows that the key factor is not only the series, but also type of cooling. Models with the index No Frost always require a more detailed check of the sensors, since there are more of them, and they are the “eyes” of the electronic brain of the refrigerator.
Diagnostics and signs of thermostat malfunction
Having understood how many thermostats in your refrigerator, you can proceed to diagnostics. The malfunction of this element is manifested by characteristic symptoms. If the thermostat is stuck open, the compressor will not start and the chamber will become warm. If the contacts are tightly closed, the refrigerator will work without interruption, which will lead to freezing of food in the refrigerator compartment and the formation of a thick coat of ice.
To check the mechanical thermostat, it must be dismantled. There are usually three or four contacts on the case. A continuity test with a multimeter at room temperature should show the circuit is closed (if it is a normally closed contact). When placing the sensitive tube of the thermostat in the cold (for example, for 10-15 minutes in the freezer), the contacts should open with a characteristic click.
In two-compressor models, diagnostics must be carried out for each circuit separately. If only one chamber does not freeze, and the second one works perfectly, the problem is almost certainly in the thermostat or compressor of this particular chamber. This greatly simplifies troubleshooting compared to single-compressor systems, where one defect stops the entire unit.
☑️ Thermostat diagnostics
⚠️ Attention: Technical characteristics and connection diagrams may vary slightly depending on the year of manufacture and the specific modification. Always check the markings of the part you are removing with the markings of the new part. The manufacturer can change component suppliers without changing the refrigerator model index.
Frequently asked questions (FAQ)
Is it possible to install a thermostat from another brand, for example, Denmark (Danfoss), in an Atlant refrigerator?
Yes, it’s often possible. Thermostat series K-59 or K-50 manufactured by Danfoss (now often labeled as Danfoss/Secop) are universal and are often used as a replacement for native Belarusian or Russian analogues (TAM, ORD). The main thing is the coincidence of the length of the capillary tube and the temperature range.
Why is there one thermostat in the two-compressor Atlanta, but not the second?
This should not happen. In a two-compressor circuit, it is necessary to have two independent control loops. If you don’t find the second thermostat, it may be hidden behind a decorative panel in the freezer, or in your case there is an electronic sensor installed that is visually different from the classic “twist.”
How to understand that the thermostat is “lying”?
If the refrigerator turns off when the chamber is still warm (food is not cooled), or turns on only when deep defrosting, it means that the thermostat calibration has gone wrong. In mechanical models, this can only be cured by replacement, since they cannot be repaired or calibrated at home.
How much does it cost to replace a thermostat in a service?
The cost consists of the price of the part itself (usually from 15 to 40 dollars depending on the brand) and the cost of the technician’s work. In two-compressor models, work may cost more due to the difficulty of accessing the second regulator.
In conclusion, we note that although the question “how many thermostats are in the Atlant refrigerator” seems simple, the answer is it requires an understanding of the structure of a specific model. Whether it is a simple single-compressor unit or a complex No Frost system, correct identification of temperature control elements is the first step to successful repair and long service life of your equipment.