Temperature regulator in the Atlant refrigerator: how it works and how to set it up

Refrigerators Atlant for decades they have remained one of the most popular in the post-Soviet space due to their reliability and maintainability. However, even with such proven technology, operational questions periodically arise - especially when it comes to temperature controller. This small but critical element is responsible for maintaining an optimal microclimate in the chambers, and its incorrect operation can lead to both food spoilage and increased energy consumption.

In this article we will look in detail at how the thermostat in refrigerators works Atlant (including series models MHM, NRM, HM and others), on what principle it works in conjunction with a compressor, and what to do if the regulator starts to “fail”. We will pay special attention a unique feature of Atlant thermostats - their compatibility with mechanical defrosting timers, which often becomes the reason confusion during diagnosis.

The material will be useful both to beginners who are just learning the basics of servicing equipment, and to experienced users who are faced with atypical symptoms - for example, when the refrigerator refuses to turn off or, conversely, “falls asleep” for several hours.

Thermostat device in the Atlant refrigerator

Thermostat (or thermostat) in refrigerators Atlant is an electromechanical device that performs two key functions:

• 🔹 Temperature control in the refrigerator compartment (in models with No Frost - also in the freezer).
• 🔹 Compressor control: on/off based on a signal from the sensor.

In most models Atlant (for example, Atlant XM 4021-000 or Atlant MXM 1708) a thermostat type K-59 or its modification (TAM-133, TAM-125) is used. These devices consist of:

• 📏 Bellows tube with refrigerant (freon), which reacts to temperature changes.
• 🔧 Contact groupsclosing/opening the compressor power supply circuit.
• 🎛️ Adjusting screw (in some models - with a spring mechanism for calibration).
• 🔌 Connection terminals to the electrical circuit of the refrigerator.

Feature of Atlanto thermostats - them mechanical nature. Unlike modern electronic regulators (for example, in refrigerators Samsung or LG), there are no microcircuits or displays. All settings are made by physically turning the knob, which acts on the contacts through a system of levers. This is both a plus (simplicity and durability) and a minus (less accuracy, susceptibility to wear).

How to distinguish a thermostat from a thermostat?

A thermostat is a full-fledged regulator with an adjustment knob and a wide temperature range. Thermal relay (for example TP-1 in some Atlanta models) is a simplified device that only turns the compressor on/off at a fixed threshold (usually +4...+6°C), without the ability to be adjusted by the user. In refrigerators Atlant classic series, thermostats are rare—mostly in freezers or in economy class models.

Operation principle: how the thermostat controls the refrigerator

The algorithm for operating the thermostat in the refrigerator Atlant can be described in four stages:

1. Temperature measurement. A bellows tube attached to the evaporator is filled with gas, which contracts or expands depending on the temperature in the chamber.
2. Mechanical impact. When warming, the gas expands, pressing on the membrane, which opens the contacts through a lever.
3. Disconnecting the compressor. An open circuit stops the supply of electricity to the compressor - the refrigerator “rests.”
4. Turning on during cooling. When the temperature rises to the upper threshold (set by the regulator knob), the gas is compressed, the contacts are closed, the compressor starts again.

Important nuance: in refrigerators Atlant with a system No Frost (for example, Atlant NRM 6228-100) the thermostat works in tandem with defrost timer i defrost sensor. Here the cycle becomes more complicated:

• 🕒 Every 8–12 hours (depending on the model), the timer starts heating the evaporator to remove frost.
• ❄️ The defrost sensor monitors the temperature of the evaporator and turns off the heating when it reaches +10...+12°C.
• 🔄 Only after this the thermostat takes control again.

It is this feature that often confuses diagnostics: if the refrigerator does not turn on for a long time, the problem may lie not in the thermostat, but in the timer or defrost sensor. For example, in the model Atlant XM 6025-031 a faulty defrost sensor can block the operation of the thermostat, simulating its breakdown.

Where is the temperature regulator and how to get to it

B refrigerators Atlant the thermostat is usually located in one of two places:

1. Inside the refrigerator compartment - under the plastic cover next to the adjustment knob (typical for models MHM, HM).
2. Outside, on the back wall —in a metal box next to the compressor (found in older models or in refrigerators with a bottom freezer).

To access the thermostat:

Remove the temperature control knob (pull it towards you or pry it with a screwdriver)

Unscrew the screws securing the plastic panel (usually 2-3 pieces)

Carefully disconnect the capillary tube from the evaporator (do not bend!)

Take a photo of the wire connection diagram before disconnecting them

Unscrew the thermostat mounting nuts and remove it-->

⚠️ Attention: In models with No Frost (for example, Atlant NRM 6226-080), the thermostat can be hidden behind the control panel along with the defrosting timer. Here you will need to remove the top cover of the refrigerator or dismantle the panel with buttons.

If you are not sure about the location of the thermostat in your model, refer to label (metal plate) on the back wall of the refrigerator. In the “Thermostat” or “Temperature control” column, the type of device is usually indicated (for example, TAM-133-1M), according to which you can find the connection diagram in the technical documentation.

How to set the temperature correctly: optimal values

The control knob in refrigerators Atlant usually has a scale from 1 to 7 (less often - to 5 or 9). However, these numbers does not correspond to degrees Celsius directly! They indicate cooling intensity level:

It is important to understand that the actual temperature depends on:

• 🌡️ Room temperature (the hotter it is, the more intense the compressor works).
• 📦 The degree of loading of the chambers (a full refrigerator is cooled longer).
• 🔄 Frequency of door opening (every time you open the chamber, warm air enters).
• ❄️ Ice thickness (in models without No Frost ice on evaporator worsens heat transfer).

Typical thermostat malfunctions and their symptoms

Thermostat in refrigerator Atlant is one of the most vulnerable places, especially after 5-7 years of operation. Its malfunction can be recognized by the following symptoms:

• ❄️ The refrigerator does not turn off Cause: the thermostat contacts are “stuck” in the closed position.
• 🔥 The refrigerator does not turn on (the compressor is silent, the light inside is on). Reason: an open circuit in the thermostat or its complete failure.
• 🌡️ The temperature does not correspond to the settings (for example, when position 3 in the chamber +15°C). Reason: loss of tightness of the bellows tube or wear of the spring mechanism.
• ⏱️ The compressor turns on too rarely or often (operation/rest cycles are shorter than 10 minutes). Reason: incorrect calibration of the thermostat or dirty contacts. data-i="206">The compressor turns on too rarely or often

⚠️ Attention: In refrigerators Atlant with a system No Frost similar symptoms can be caused by a malfunction defrost sensor or timer. For example, if the sensor. “freezes” in the “defrosting” position, the compressor will not turn on, even if the thermostat is working. To exclude this reason, listen: in the defrosting mode you should hear a faint sound of the evaporator heater operating.

To accurately diagnose the thermostat you will need multimeter. Check procedure:

1. Unplug the refrigerator and get to the thermostat.
2. Disconnect the wires from the terminals (after photographing the circuit!).
3. Switch the multimeter to resistance testing mode (ohmmeter) and connect the probes to the terminals 3 and 4 (in most models Atlant this thermostat contacts).
4. At room temperature, the resistance should be close to 0 Ohm (contacts are closed).
5. Place the thermostat in cold water (for example, with ice) - the resistance should become infinite (1 on the multimeter screen), since the contacts will open.

If the contacts do not open/close when the temperature changes, the thermostat is faulty and requires replacement. In models Atlant with electronic control (for example, Atlant XM 6321-089) can be used instead of a mechanical thermostat thermistor - it is checked according to a different principle (measuring resistance at different temperatures).

Replacing the thermostat with your own hands: step-by-step instructions

If diagnostics have confirmed that the thermostat is faulty, you can replace it yourself. For refrigerators Atlant thermostats of the following types are suitable:

• 🔧 K-59 (universal, suitable for most models).
• 🔧 TAM-133-1M (for refrigerators with one compressor).
• 🔧 TAM-125 (for freezers or two-compressor models).
• 🔧 RTK-1 (for old Soviet models produced before the 2000s).

To replace you will need:

• ⚒️ Phillips screwdriver and flat.
• 🔌 Pliers or side cutters.
• 📸 Phone for photographing the connection diagram.
• 🧊 New thermostat (necessarily the same model!).

⚠️ Attention: In refrigerators Atlant with the system No Frost replacing the thermostat often requires additional adjustment of the defrost timer. If after replacement the refrigerator is unstable (for example, the compressor turns on for 5-10 seconds and turns off), check the position of the timer arrow - it should point to 0 (beginning of the cycle).

Step-by-step replacement process:

1. Unplug the refrigerator and defrost it (if ice prevents access to the thermostat).
2. Remove the temperature control knob and the plastic panel (as described above).
3. Disconnect the capillary tube from the evaporator. Be careful - it is fragile!
4. Take a photo of the connection of the wires to the thermostat terminals Atlant the following pinout is used:
   • Terminal 3 — common wire (usually brown or red).
   • Terminal 4 —wire to the compressor (black or orange).
   • Terminal 6 — wire to the light bulb (if any).

Unscrew the nuts securing the thermostat and remove it.

Install a new thermostat, connect the wires according to the diagram and secure the capillary tube.

Assemble the panel in the reverse order.

After replacement, turn on the refrigerator and check its operation for 2-3 hours. The optimal sign of a successful replacement:

• ✅ The compressor turns on and off at intervals of 20-40 minutes.
• ✅ Temperature in the refrigerator compartment stabilizes at +4...+6°C.
• ✅ There are no extraneous sounds (clicks, crackles) when the thermostat operates.

Frequent errors when working with the temperature controller

Even experienced users sometimes make mistakes that lead to thermostat failure or improper operation of the refrigerator Here are the most common ones:

• 🔧 Tightening the nuts too much when. installation of the thermostat. This may damage the housing or deform the capillary tube, which will lead to gas leakage.
• 🔌 Confusion with wires when connecting For example, if you mix up the terminals 3 and 4, the compressor will work. constantly.
• ❄️ Ignoring ice during diagnostics. In models without No Frost a thick layer of ice on the evaporator can block the operation of the thermostat, simulating its breakdown.
• 🌡️ Setting the temperature “by eye”. Many users set the knob to maximum (7) in the summer, not taking into account that this increases the load on the compressor and reduces its resource.
• 🔄 Frequent switching on/off of the refrigerator to “reboot” This can damage not only the thermostat, but also the starting unit. relay.

Another typical mistake is trying to repair a mechanical thermostat. Unlike electronic devices, mechanical thermostats Atlant cannot be repaired: they are either cleaned (if the problem is in oxidized contacts) or replace entirely. Soldering or stripping the contacts will give a temporary effect, but after 1-2 months the fault will return.

⚠️ Attention: In refrigerators Atlant with an electronic display (for example, Atlant XM 6326-080), replacing the thermostat may require reflashing the control board. This is due to the fact that the microcontroller “remembers” the parameters of the old sensor. In such cases, it is better to contact the service center.

FAQ: Answers to frequently asked questions about the regulator in the Atlant refrigerator

Is it possible to install a thermostat from another refrigerator (for example, from Stinol or Indesit)?

Theoretically yes, but only if the model The thermostat is completely identical (for example, K-59 is suitable for many brands). However, there are nuances:

• The length of the capillary tube must match - otherwise the sensor will not operate correctly.
• The pinout of the terminals may differ (for example, in Indesit terminal 6 sometimes used to connect a fan).
• In refrigerators with No Frost the thermostat must be compatible with the defrost timer of a specific model.

It is better to buy an original spare part or an analogue recommended for Atlant (for example, TAM-133-1M-15).

Why did the refrigerator start working after replacing the thermostat louder?

This is normal if:

• The new thermostat is more sensitive and turns on the compressor more often (especially if you installed a model with a different response threshold).
• When replacing, you accidentally lost the position spring shock absorbers of the compressor - check if it touches housing.

If the noise is accompanied by vibration or knocking, installation errors are possible:

• The capillary tube of the thermostat touches the walls of the refrigerator and transmits vibration.
• Incorrectly connected wires, and the compressor operates in emergency mode.

How to check the thermostat without a multimeter?

Method 1: Ice test.

1. Unplug the refrigerator.
2. Remove thermostat and put it in the freezer for 30–40 minutes.
3. Take it out and immediately connect it to the wires (observing polarity!).
4. If the compressor does not start, the thermostat is faulty (the contacts did not close from the cold).

Method 2: Direct circuit (only for mechanical thermostats!).

1. Disconnect the wires from the terminals 3 and 4 thermostat.
2. Connect them together with a piece of wire (short-circuit).
3. If the compressor works, the problem is in the thermostat.

⚠️ Attention: Do not use the second method for more than 1-2 minutes - this may burn the compressor!

What to do if the regulator knob scrolls “idly”?

This is a typical problem for refrigerators Atlant over 10 years old Reasons:

• 🔧 The plastic rodconnecting the handle to the thermostat mechanism is broken.
• 🔧 Loose spring inside the thermostat (the adjusting screw is not fixed).
• 🔧 The handle is cracked and scrolls on the axis.

Solutions:

• If the rod is broken, the thermostat will need to be replaced.
• If the problem is in the handle, you can buy a new one (they are sold separately for popular models Atlant).
• Temporary solution: fix the handle in the desired position with electrical tape (but this is inconvenient for adjustment).

Which thermostat is better - mechanical or electronic?

For refrigerators Atlant mechanical thermostats (K-59, TAM-133) have several advantages:

• ✅ Cheaper by 2–3 times (price ~500–1500 rubles versus 3000–5000 rubles for an electronic one).
• ✅ Easier to replace (does not require configuration or firmware).
• ✅ More reliable in conditions of voltage surges.

Electronic thermostats (for example, in models Atlant with a display) more accurately maintain the temperature, but:

• ❌ More expensive and more difficult to repair.
• ❌ Sensitive to power surges (can burn out during a thunderstorm).
• ❌ Require calibration after replacement.

The choice depends on the refrigerator model: in classic Atlant (for example, MHM 1840), a mechanical thermostat is optimal, and in modern ones (XM 6326) an electronic one is already built into the system controls.