The situation when food in the refrigerator compartment begins to freeze or, conversely, quickly deteriorates, often confuses the owner. It seems that the equipment is out of order, and they are already preparing to call a technician or buy a new unit. However, in most cases, the problem is solved by simply adjusting the settings of the thermostat, which is responsible for maintaining the microclimate inside the chambers.
Many users mistakenly believe that the numbers on the regulator scale indicate degrees Celsius. This common misconception leads to the fact that the device is set to “minimum” and the food is frozen. Understanding the logic of mechanical and electronic control is the key to the correct operation of your equipment Indesit, Atlant or LG.
In this article we will analyze the universal principles of setting, the operating features of different types of thermostats and the nuances that will help extend the life of the compressor. You will learn to determine the optimal operating mode without the use of complex measuring equipment.
The principle of operation of a mechanical thermostat
A mechanical regulator, or thermostat, is a simple device that closes and opens an electrical circuit depending on the temperature of the evaporator. Inside the housing there is a sensitive element - a bellows filled with gas or liquid. When heated, the gas expands and puts pressure on the membrane, opening the contacts, and when cooled, it contracts, closing the circuit and starting the compressor.
When you turn the regulator knob, you change the tension of the spring that acts on the contacts. The tighter the spring is tensioned, the more difficult it is for the gas in the bellows to break the circuit, and the longer the compressor will work, cooling the chamber. That is why an increase in the number on the scale does not mean an increase in temperature, but on the contrary, an increase in cooling capacity.
It is important to understand that the scale from 0 to 7 (or 1 to 5) is not a linear scale of degrees. The number “1” means minimum cooling (the compressor works in short cycles), and the maximum number means maximum cooling (the compressor works almost non-stop). Correct setting requires a balance between these extremes.
It is worth noting that the logic may differ slightly in different refrigerator models, but the general principle “more numbers, more cold” remains the same in 95% of cases of mechanical control. This applies to both old Soviet models and modern budget lines.
⚠️ Attention: Never turn the thermostat knob sharply or forcefully. The mechanism inside is fragile, and excessive force can lead to breakage of the shaft or displacement of the calibration spring, after which the numbers on the scale will no longer correspond to reality.
Deciphering the numerical values on the scale
The most common question from users is: “What number should I set the regulator to?” The answer depends on the time of year, the load on the refrigerator and the ambient temperature in the room. Let's look at the standard scale that is found on thermostats Danfoss, Thermostat and their analogues.
The “0” or “Off” position means a complete shutdown of the power supply to the compressor. In this mode, the refrigerator does not cool, but the internal light may remain on. This position is used for defrosting or long-term downtime of equipment. If you turn the knob and the refrigerator does not turn on, check whether the regulator is at zero.
Average values (usually 2, 3 or 4) are optimal for daily use. In these positions, the refrigerator maintains the temperature in the main chamber in the range of +3...+5°C, which is ideal for storing most products. The compressor turns on cyclically, giving the engine a rest.
Maximum values (6, 7 or Max) put the unit into intensive freezing mode or operation in an extremely hot room. Continuous operation at maximum leads to rapid wear of the compressor, freezing of the rear wall and excessive consumption of electricity. Use this mode only for a short time.
Below is a table that will help you navigate the values for the standard scale from 1 to 7:
| Value on the scale | Operating mode | Temperature conditions (approximate) | Recommendation |
|---|---|---|---|
| 0 / Off | Off | — | For defrosting |
| 1 - 2 | Minimum cold | +5...+7°C | Summer, low loading |
| 3 - 4 | Normal mode | +2...+5°C | Standard operation |
| 5 - 6 | Enhanced cooling | 0...+3°C | Heavy load, heat |
| 7 / Max | Frozen | Lower 0°C | Only for a short time |
Seasonal adjustment of settings
Temperature environment directly affects the efficiency of the refrigerator. In the summer, when the kitchen is hot, heat exchange in the condenser (the black grill at the back) is difficult. The compressor takes more time to cool the refrigerant and return it to the evaporator.
In winter, the situation changes. If the refrigerator is in an unheated room or near a window, it requires less effort to cool. However, if the room is too cold (below +10°C), the oil in the compressor may thicken, and the gas in the thermostat may stop expanding, which is why the engine may not start at all.
For mechanical regulators, the following rule applies: in the summer we turn towards larger numbers (increase the cold, since heat loss is large), and in winter - towards smaller ones. This may seem counterintuitive (“it’s cold in winter, why cool it?”), but in fact we regulate the duration of the motor operation so that it does not run idle or, on the contrary, does not overheat.
Do not forget that the location of the refrigerator also plays a role. If it is located near a radiator or in direct sun, even in winter it may require increasing the cooling power. Conversely, in a cool pantry, the settings should be minimal.
☑️ Checking operating conditions
Features of electronic control panels
Modern models such as Samsung, LG or Bosch, are often equipped with electronic control. There is no mechanical knob with numbers, and the temperature is set in degrees Celsius on the display. The operating logic remains the same, but the interface becomes more understandable.
On the display you see the actual or target temperature. By pressing the "Temp" or "Fridge" buttons you change the value. Unlike mechanics, here a lower number means a cooler setting. For example, a setting of +2°C will cool food more than +6°C.
Electronics often have “Eco”, “Smart” or “Vacation” modes. In vacation mode, the refrigerator switches the refrigerator compartment to an economical mode (about +15°C) so that the food does not disappear, but does not consume excess electricity, and the freezer continues to operate as normal.
It is important to know that after changing the settings on the electronic display, the refrigerator needs time (from 2 to 10 hours) to stabilize the temperature. Do not try to “speed up” the process by repeatedly switching the buttons - this will only disrupt the algorithm of the controller.
⚠️ Attention: In some models with electronics, when the light is turned off, the settings may be lost. If after a power surge the refrigerator begins to work incorrectly, perform a full reset or reprogram them according to the instructions.
How to check the correct settings without a thermometer
Do you not have a special thermometer at hand? No problem. The accuracy of the setting can be checked by assessing the condition of the products and the operation of the compressor. This is a “folk” method that is often used by specialists for initial diagnosis.
Pay attention to the vegetables and fruits stored at the back wall. If they begin to freeze, become covered with an icy crust, or become sluggish and watery, it means the temperature is too low. It is necessary reduce the power (turn the knob towards lower numbers).
If the milk quickly sours (before the expiration date), and the butter remains soft even on a shelf against the wall, then the cold is not enough. In this case, the regulator must be turned towards increasing the value. Also a sign of a lack of cold is the frequent activation of the compressor without a sufficient rest period.
Another indicator is the formation of a “fur coat” (snow crust) on the back wall of the refrigerator compartment. In Direct Cool systems (drip system), slight thawing and ice formation is normal, but if the layer of snow becomes thick and prevents you from closing the door, this is a signal of freezing.
Why do food at the back wall freeze?
In refrigerators with a drip system, the back wall is the evaporator. It is on this that moisture from the air freezes, turning into ice. When the compressor stops, this ice melts and flows into the drain. If you set the regulator to maximum, the wall does not have time to thaw, and the ice “crawls” onto the food. The solution is to reduce the cooling power.
Frequent errors during operation
One of the most serious mistakes is an attempt to compensate for poor operation of the refrigerator (for example, due to worn rubber seal) by maximizing the thermostat setting. Users turn the knob to “7”, thinking that this will correct the situation. In fact, this leads to the compressor working without stopping, its overheating and eventual breakdown.
Another mistake is frequent changes in settings. Thermal stability in the chamber is not achieved instantly. If you just changed the value, give the unit at least 3-4 hours to return to mode. Constantly “playing” with the regulator disorients the system and leads to temperature fluctuations, which is harmful to the products.
Also, users often ignore loading the chambers. An empty refrigerator and one completely filled with food require different settings. Thermal capacity of products great: a full refrigerator keeps the cold longer, but also cools down longer when initially loaded. An empty unit reacts faster to opening the door.
Do not forget to ventilate the chamber before setting it up again. If you have just defrosted your refrigerator or loaded it with warm food, the temperature sensor may show incorrect readings. Allow the chamber to cool to room temperature before final calibration of the controller.
Diagnostics of thermostat malfunctions
There are situations when turning the regulator knob becomes useless. This happens when the thermostat itself has failed. The main signs of a malfunction: the refrigerator does not turn on at all (even at maximum) or, on the contrary, it works non-stop, freezing all the contents, regardless of the position of the handle.
In the first case (it does not turn on), the “resuscitation” method often helps: with the refrigerator plugged in, try quickly turning the control knob from the extreme left to the extreme right and back several times. Sometimes this helps to “break through” stuck contacts.
If the refrigerator does not turn off, and the food in the main chamber has turned into ice, and adjusting the knob does not change the operating mode (the compressor continues to hum), then the thermostat is “stuck” in the closed state. In this case, replacement of the part is required.
It is also worth checking the integrity of the thermostat capillary tube (if it is visible). If there are traces of oil on the tube or it is pinched, gas could escape and the regulator no longer senses temperature. In this case, adjustment is pointless.
Can the regulator be used to quickly freeze fresh food?
Yes, many mechanical thermostats allow you to briefly turn on the maximum power mode (number 7 or the “Fast Freeze” button). This will help you quickly freeze fresh berries or meat. However, do not keep the refrigerator in this mode for more than 12-24 hours, otherwise you risk freezing the remaining food and overheating the motor.
Why does nothing change in the chamber after adjusting the temperature?
The refrigerator needs time (inertia) to change the internal temperature. After turning the knob, wait at least 2-3 hours. If during this time the nature of the motor operation (frequency of switching on) has not changed, the thermostat itself may be faulty or there is a freon leak.
What to do if the control knob spins endlessly?
If the knob scrolls in a circle without clicks and limiting the stroke, this is a sign of a breakdown of the internal thermostat mechanism. Most likely, the axle burst or the spring jumped off. In this position, the regulator does not control the temperature. Part replacement is required.