Owners of premium-class refrigeration equipment are often faced with a situation where it is necessary to precisely adjust the microclimate inside the chambers, but there is no digital display on the front panel. Such brand models Liebherr use a mechanical regulator with a scale from 1 to 7. Understanding the principle of operation of this switch is critical to maintaining the freshness of products and the energy efficiency of the device. Incorrect setting can lead to damage to the contents or the formation of excessive ice.
Many users mistakenly believe that the number on the regulator corresponds to the number of degrees Celsius. This is a fundamental misconception that often causes equipment breakdowns or stock defrosting. In fact, the values from 1 to 7 indicate the intensity of the compressor, and not a specific temperature. The higher the number, the colder it will be inside the refrigeration chamber.
In this article we will look in detail at what temperature is hidden behind each division of the scale, how to make adjustments correctly depending on the time of year and the load of the chambers. Typical operating errors that can shorten the service life of your refrigeratorwill also be discussed. Proper setting of the thermostat is the key to long and trouble-free operation of the equipment.
The principle of operation of the Liebherr mechanical thermostatThe mechanical thermostat in refrigerators Liebherr is a sensor that responds to changes in temperature inside evaporator or chamber air. When you turn the knob, you change the trigger point of the contact group. In position "1", the compressor turns on less often and works for a shorter time, maintaining a lower temperature.
When the knob is switched to position "7" (or "Max"), the contacts close almost constantly, forcing the unit to work continuously or with minimal pauses. This allows you to quickly cool the products, but creates an increased load on the engine. Thermostat such models do not have a digital display, so the user must rely on the values recommended by the factory for everyday use.
⚠️ Attention: Never leave the regulator in the maximum power position (7) on a permanent basis in normal mode. This can lead to freezing of food, freezing of the back wall and premature wear of the compressor.
It is important to understand that the mechanical system is less accurate than the electronic one and has a certain error. The readings are also influenced by external factors: room temperature, frequency of door opening and the number of loaded products. Therefore, the value on the scale is more of a guideline for the cooling power than a rigid fixation of degrees.
Decoding the scale: from one to sevenTo set it correctly temperature, you need to clearly understand the relationship between the number on the regulator and the real climate inside the chamber. The scale from 1 to 7 is universal for many models Liebherr with mechanical control. Let's look at what each position means and when it is advisable to use it.
Position "1" (Min) corresponds to the warmest mode. In this case, the temperature can rise to +8...+10°C. This value is rarely used for primary storage, except for short-term storage of vegetables that are afraid of the cold, or when the refrigerator is almost empty. Positions "2" and "3" are optimal for summer or cool rooms, providing a temperature of about +5...+7°C.
The golden mean for most use scenarios is position "4" or "5". It is these values that make it possible to maintain the standard +4...+5°C required for storing meat, dairy products and ready meals. Modes "6" and "7" are intended for quick freezing or work in very hot rooms, but require constant monitoring.
- 🌡️ Position 1-2: Minimum cooling, temperature up to +8°C, suitable for energy saving.
- ❄️ Position 3-5: Standard operating mode, temperature +3...+5°C, ideal for daily storage.
- 🧊 Position 6-7: Maximum power, temperature about 0°C and below, only for quick freezing or heat.
⚠️ Attention: In refrigerators with mechanical control there is no digital sensor means that the actual temperature may differ from the expected one by 1-2 degrees depending on the load of the chambers.
Correspondence of numbers to degrees CelsiusAlthough the mechanical regulator does not show degrees, Liebherr engineers calibrate the scale so that the average values correspond to sanitary standards storage Below is a table showing the approximate correspondence between the position of the regulator knob and the temperature inside the main refrigerator compartment at normal room temperature (+20...+22°C). Liebherr calibrate the scale so that the average values correspond to sanitary storage standards. Below is a table showing the approximate correspondence between the position of the control knob and the temperature inside the main refrigerator compartment at normal room temperature (+20...+22°C).
Position of the regulator
Approximate temperature (°C)
Recommended use
1 (Min)
+8 ... +10
Short-term storage, almost empty chamber
3
+6 ... +7
Summer period, storage of vegetables and fruits
4-5
+3 ... +5
Daily mode, optimal for most products
7 (Max)
0 ... +2
Fast freezing, extremely hot room
It should be noted that in the freezer there is a dependence is similar, but the absolute temperature values will be negative. When setting the regulator to "4", the freezer usually reaches the standard -18°C. If you turn the knob to “7”, the temperature can drop to -24°C and below, which will trigger the intensive freezing mode.
Why are there no exact numbers on the mechanics?
Mechanical thermostats work based on the expansion of gas or a bimetallic plate. The accuracy of such devices is lower than that of electronic sensors, so the manufacturer indicates ranges rather than exact values. This is a design feature, not a defect.
| Position of the regulator | Approximate temperature (°C) | Recommended use |
|---|---|---|
| 1 (Min) | +8 ... +10 | Short-term storage, almost empty chamber |
| 3 | +6 ... +7 | Summer period, storage of vegetables and fruits |
| 4-5 | +3 ... +5 | Daily mode, optimal for most products |
| 7 (Max) | 0 ... +2 | Fast freezing, extremely hot room |
Why are there no exact numbers on the mechanics?
Mechanical thermostats work based on the expansion of gas or a bimetallic plate. The accuracy of such devices is lower than that of electronic sensors, so the manufacturer indicates ranges rather than exact values. This is a design feature, not a defect.
The influence of external factors on the settingsThe operating efficiency of your Liebherr refrigerator directly depends on environmental conditions. A mechanical thermostat reacts not only to the internal temperature, but also indirectly depends on heat inflows from the outside. If the room is hot, the compressor takes longer to reach the set cut-off point.
In the summer, when the temperature in the kitchen exceeds +25°C, it makes sense to move the regulator one notch upward (for example, from 4 to 5). This compensates for the increased heat load. Conversely, in winter, if the refrigerator is in a cool room, the value can be reduced to 3 to avoid excessive hypothermia and the compressor running idle.
- 🏠 Location: If the refrigerator is located next to a stove or radiator, the regulator should be set to higher values.
- 🚪 Opening frequency: In large families, where the door open frequently, the cooling power should be higher (position 5).
- 📦 Loading: A full chamber holds the cold better, but requires more energy for initial cooling, it is better to keep an empty one at a minimum.
Algorithm for correct temperature controlFor initial setup or adjusting the operating mode after defrosting, you must perform the steps sequentially. Sharp switching of the handle back and forth can throw off the calibration of the mechanical sensor. First, determine the current situation: the food has just been loaded or the refrigerator is operating normally.
If you have just turned on the device or loaded a lot of warm food, set the control to 6 or 7. This will allow you to quickly gain cold. As soon as the food has cooled (after 4-6 hours), be sure to return the knob to position 4 or 5. Long-term operation at maximum is harmful to equipment.
☑️ Checking the refrigerator settings
Done: 0 / 4
During operation, monitor the condition of the products. If the milk quickly turns sour and the meat loses color, add power (move to 5-6). If vegetables freeze at the back wall, and a thick layer of frost appears on the walls, reduce the power (move to 3). Balance is the key word in setting up the mechanics.
Typical errors when operating a thermostatOne of the most common mistakes is ignoring seasonal ones changes. Users leave the regulator in position "3" in winter, when the apartment becomes cooler, and wonder why food spoils faster. Mechanics require human attention, unlike smart electronic systems Liebherrthat correct the work themselves.
Another mistake is an attempt to “deceive” the thermostat by turning it to maximum each time you load food and forgetting to turn it back. This leads to the fact that the evaporator becomes overgrown with a “fur coat”, the fan (if there is one) can become jammed with ice, and the compressor wears out. Constant operation in mode "7" reduces the unit's life by 30-40%.
⚠️ Attention: If you hear that the refrigerator turns on too often or works without stopping even at minimum settings, the problem may not be in the regulator, but in a freon leak or a sensor malfunction. In this case, twisting the knob will not help - you need a master.
Also, you should not change the settings often within one day. The thermostat needs time to stabilize the temperature. Constant jumps in values disorient the control system and lead to an unstable climate inside the chambers.
☑️ Checking the refrigerator settings
Diagnostics of regulator malfunctionsHow to understand that a mechanical thermostat has failed? The first sign is that the behavior of the refrigerator does not correspond to the set position of the handle. For example, you set the regulator to “1”, and the refrigerator freezes so much that the water in the door freezes. Or vice versa: at “7” the compressor is silent and does not start.
In some cases, the effect of “sticking” of the contacts may be observed. The refrigerator either does not turn on at all or hums continuously without turning off. It is difficult to visually check a mechanical sensor, since it is hidden inside the housing. However, if turning the knob is not accompanied by a characteristic click (although in some models it may be quiet or absent in certain ranges), this is a cause for concern.
If you suspect a breakdown, try gently tapping the regulator knob (without fanaticism). Sometimes this helps to separate stuck contacts, but this is only a temporary measure. For accurate diagnostics, it is necessary to test the contacts with a tester at different temperatures, which is best left to a specialist.
What to do if the regulator knob scrolls endlessly?
If the thermostat knob scrolls 360 degrees or more without characteristic stops or clicks, this may mean a breakdown of the internal mechanism of the regulator or the rod jumping off axes. In some models, the extreme positions (Min/Max) have limiters. If they are not there, the thermostat needs to be replaced.
Is it possible to replace a mechanical thermostat with an electronic one?
Theoretically this is possible, but in practice it requires complex modifications to the housing, control board and sensor system. The plant Liebherr has not provided for such modernization. It is cheaper and more reliable to replace a failed mechanical sensor with an original analogue.
Why is the refrigerator very cold even on unit?
This is a sure sign of a thermostat malfunction: its contacts are “stuck” in a closed state, and it does not give a command to turn off the compressor. You cannot operate the equipment in this mode - the food will freeze and the compressor will burn out. The sensor needs to be replaced.
Where is the temperature regulator located in a Liebherr refrigerator?
In models with mechanical controls, the regulator is usually located inside the refrigerator compartment on the right or left side wall, sometimes hidden by a decorative panel or located in the upper corner. In some older models, it can be combined with a lighting lamp.