Refrigerators Stinol (Stinol) produced by the Liebherr plant, which were actively supplied to Russia in the 90s and early 2000s, have proven themselves to be reliable and repairable units. However, time takes its toll, and over time, owners are faced with the need to intervene in the operation of the thermostat. Users often notice that the food in the chamber begins to freeze or, conversely, quickly deteriorates due to insufficient cold. This is the first signal that temperature calibration the factory settings are broken or lost.
Unlike modern models with electronic controls and displays, in older Stinol models, such as Stinol-101, Stinol-102 or Stinol-103, control carried out mechanically. There are no complex microcircuits here, and a classic thermostat is responsible for maintaining the microclimate. Understanding the principle of its operation and knowing the location of the adjusting elements will allow you to correct the situation yourself without calling a technician. The main thing is to act consistently and know where the adjusting screws are. Before you begin any manipulations, it is important to determine whether the problem really lies in the thermostat settings, or whether it is a more serious malfunction, for example, a freon leak or a compressor failure. If the refrigerator hums, works constantly, but does not freeze, or the motor does not start at all, then simply tightening the screw will not help. In this article we will consider scenarios when the unit is functioning, but the temperature regime does not meet expectations, and mechanical adjustment is required adjusting screws.
Before proceeding with any manipulations, it is important to determine whether the problem really lies in the thermostat settings, or whether it is a more serious problem, such as a freon leak or compressor failure. If the refrigerator hums, works constantly, but does not freeze, or the motor does not start at all, then simply tightening the screw will not help. In this article we will consider scenarios when the unit is operating, but the temperature conditions do not meet expectations, and it is required mechanical adjustment.
The principle of operation of the Stinol mechanical thermostat
The main element of the control system in old Stinol refrigerators is thermostat (thermostat). This device is a sealed system filled with gas or liquid that responds to changes in temperature in the evaporator. When the temperature inside the chamber rises, the gas expands and opens the contacts, starting the compressor. When a predetermined threshold is reached, the gas is compressed and the circuit opens, stopping cooling. Models Stinol-104 and Stinol-110 often use series thermostats K-59 or TAM-133.
The handle located inside the refrigeration chamber is mechanically connected to a spring inside the thermostat. By turning the knob, you change the tension force of this spring, thereby setting the response threshold. However, the factory calibration may be lost due to vibrations during transportation, power surges, or natural aging of the spring metal. It is to compensate for these changes that it is possible fine tuning through special holes in the regulator body.
⚠️ Attention! The thermostat is energized at 220 volts. Any adjustment work requiring removal of the casing or contact with electrical terminals should only be carried out with the refrigerator completely disconnected from the network. Failure to follow safety precautions may result in electric shock.
It is worth noting that in dual-compartment models with one compressor, such as Stinol-202 or Stinol-205, the thermostat usually controls the temperature only in the refrigerator compartment. The freezer compartment is cooled according to the residual principle or through a separate circuit, but the control element is still the sensor of the “plus” chamber. Therefore, adjusting the screw primarily affects the upper compartment, and the change in temperature in the freezer occurs proportionally.
Diagnostics: when adjustment is needed
Before grabbing a screwdriver, you need to clearly understand the symptoms. Illiterate intervention in the settings can aggravate the situation, causing the compressor to wear out or, conversely, leading to defrosting of food. There are several obvious signs indicating the need for temperature adjustments.
First of all, pay attention to the engine operating cycles. If the refrigerator turns on too often and operates for short periods of time, while the compartment is warm, this may indicate that the shutdown threshold is set too high. And vice versa, if the unit works almost without stopping, and a “coat” of ice forms on the back wall of the refrigerator compartment, it means that the temperature has dropped below the required minimum, and it is necessary to loosen the tension.
For accurate diagnosis, it is recommended to use an external thermometer placed in a glass of water on the middle shelf. This will give an objective picture, since built-in indicators (if any) or “eyeball” sensations are often erroneous. The normal temperature for storing food is considered to be from +2 to +5 degrees Celsius. If, when the thermostat knob is positioned at “3” (average value), the thermometer shows +8°C or -2°C, it is necessary screw calibration.
It is also worth checking the condition of the seals and the cleanliness of the condenser. Sometimes the problem is not in the settings, but in the fact that the door does not fit tightly, or the radiator on the back wall is clogged with dust. In such cases, adjusting the thermostat will only give a temporary effect or will not help at all. Make sure that the ventilation holes inside the chamber are not blocked if we are talking about models with the system No Frost or Frost Free.
Location of adjustment elements
In old-style Stinol refrigerators, the adjustment screws are located directly on the thermostat body. To get to them, you need to remove the plastic mode switch knob and, in some cases, the decorative trim. The design may vary slightly depending on the model of thermostat installed, be it Orbital, Ranco or Danfoss.
Usually there are one or two small holes on the front of the thermostat, where the handle is attached. They may be covered with plastic plugs or sealing paint, which will have to be carefully removed. Models Stinol-101 and Stinol-103 often use a thermostat with one adjusting screw located in the center of the axis of rotation of the handle. In more complex modifications, there may be two of them: one for adjusting the range, the other for the differential.
Where exactly to look for the screw?
Usually the adjusting screw is located under the removable thermostat handle. Remove the handle by pulling it towards you (sometimes a slight wiggle is required). Underneath you will see the thermostat stem and housing. Look for a hole with a diameter of 2-3 mm. In some models, access is through a hole in the plastic panel where the screw slot is visible.">To access the screw, you often need to remove the handle itself. It is held in place by friction. Carefully, using a flat-head screwdriver, pry the handle from different sides, trying not to damage the plastic, which has become brittle over the years of use.
It is important to distinguish between the screws. If there are two of them, then usually the one that is closer to the center or has marking, is responsible for the on/off temperature (range), and the second is for the temperature difference (hysteresis). For domestic purposes, as a rule, it is necessary to adjust the main screw responsible for temperature range. Do not try to turn the screws blindly without understanding their purpose, this may lead to incorrect operation of the automation.
Step-by-step instructions for adjusting the temperature
The adjustment process requires patience and accuracy. Do not expect an instant result after one turn of the screw, since the system needs time to stabilize the temperature. Before starting work, prepare a small slotted screwdriver that fits freely into the adjustment hole and a thermometer for control.
Perform the steps as follows. following sequence:
- 🛑 Disconnect the refrigerator from the power supply and defrost the chamber if there is ice in it. Remove all products.
- 🔧 Remove the thermostat knob and find the adjustment hole on the body of the device.
- 📏 Fix the current position of the screw (you can make a mark with a marker on the end of the screw) to be able to return to the original settings.
- 🔄 Turn the screw half a turn clockwise to increase the temperature or counterclockwise to lower it.
- ⏳ Turn on the refrigerator and wait 3-4 hours until the mode is completely stabilized before checking again.
☑️ Adjustment checklist
The direction of rotation of the screw is critically important. Clockwise (to the right) you usually tighten the spring, which requires a lower temperature for the contacts to operate (the refrigerator will freeze more). Counterclockwise (to the left) the tension will loosen and the compressor will shut down at higher temperatures. Make micro-movements, no more than 45-90 degrees at a time, since thermostat sensitivity high.
After each stage of adjustment, be sure to take a control measurement with a thermometer. If after a full cycle (on-off) the temperature is not within the normal range, repeat the procedure. Remember that the screw does not regulate the instantaneous temperature, but the automatic response thresholds. It is a mistake to think that turning the screw will immediately change the thermometer readings; the change will occur only after the next compressor operation cycle.
Table of typical faults and elimination methods
For ease of diagnosis and selection of adjustment method, use the table below. It will help to compare the observed symptoms with the necessary actions. Please note that some problems may require not only adjustment, but also replacement of components.
| Symptom | Probable cause | Action | Result |
|---|---|---|---|
| The refrigerator does not turns off, the chamber is colder than -5°C | The range is off, the spring tension is weak | Turn the screw clockwise (increase the tension) | The shutdown temperature will increase |
| Frequent switching on, in the chamber is warmer than +8°C | The spring tension is too strong | Turn the screw counterclockwise (loosen) | The shutdown temperature will decrease |
| The compressor runs constantly, there is no cold | Freon leak or compressor breakdown | Adjustment will not help, repairs are needed | A technician needs to be called |
| Ice on the back wall, food in the refrigerator compartment freezes | The temperature threshold is set too low | Adjustment with a screw towards increasing degrees | Normalization of the storage mode |
This table describes standard situations for mechanical thermostats. However, it is worth considering that the characteristics may vary depending on the specific modification of the thermostat installed on your Stinol. If you are not sure of your actions, it is better to limit yourself to observing the current settings.
Typical errors when setting
The most common mistake is trying to set the ideal temperature in one go. Users turn the screw a few turns, expecting an instant effect, and then wonder why the refrigerator stopped freezing or, conversely, turned the food into ice. Inertia of the system is great, and haste is the main enemy here.
Another mistake is to ignore the state of the thermostat itself. If the device is physically worn out, the contacts are burnt, and the bellows has lost its tightness, no adjustment with a screw will save the situation. In such cases, it is required replacing the thermostat for a new one. You can understand that the thermostat has “died” if you don’t hear a click when you turn the knob, or if testing the contacts with a tester shows a break or a permanent short circuit.
⚠️ Attention! Do not use harsh chemicals or water to clean the internal mechanisms of the thermostat. Moisture getting inside the device will cause corrosion of the contacts and irreversible damage, which will require replacement of the entire assembly.
Adjustment when the chamber is not fully loaded or with the doors open is also considered an error. The result must be tested under normal operating conditions. An empty chamber cools and heats up differently than a full one, so it is better to make final adjustments to the settings when the refrigerator is filled with the usual volume of food.
FAQ: Frequently Asked Questions
Is it possible to regulate the temperature in a working refrigerator?
Technically, you can turn the screw with the motor running, but this is not recommended. Firstly, you won't see the real effect right away due to inertia. Secondly, there is a risk of a short circuit if the screwdriver slips onto the live contacts. It is safer to turn off the unit, make adjustments, and then turn it on to check.
What to do if the screw spins endlessly and the temperature does not change?
This is a sign that the adjusting mechanism inside the thermostat is broken or the limit of its mechanical travel has been reached. It's also possible that you're turning the wrong screw (for example, a differential screw that doesn't affect the average temperature). If the screw turns without resistance, most likely you need replacement of the thermostat.
What temperature should be in an old-style Stinol freezer?
For freezers of older models, the norm is a temperature of -18°C and below. If you set the refrigerator compartment to +4°C, then in the freezer operating from the same circuit it should be about -18...-20°C. If the refrigerator compartment is normal, but the freezer is -6°C, the problem is not in the thermostat, but in a freon leak or a clogged capillary tube.
How often do you need to re-adjust?
A working thermostat does not require constant adjustment. If you have to tighten the screws every few months, then the device has deteriorated. The metal of the spring is tired, and the settings “float”. In this case, it is more economically feasible to buy a new thermostat than to constantly torture the old one.