The situation when the refrigerator stops freezing properly or, conversely, turns food into ice blocks, often confuses the owner. In most cases, the reason for this behavior of household appliances is not the failure of the compressor, but a banal imbalance thermostat. It is this small device that is responsible for maintaining the set temperature inside the chambers.
Thermostat K59 is one of the most common components in modern refrigerators. Its main task is to open and close the electrical circuit depending on the temperature of the evaporator. If you notice that food is spoiling faster than usual or too much ice is freezing, it may be time to diagnose and adjust this unit.
Before you begin any manipulations, you need to make sure that the problem lies precisely in the settings or calibration of the sensor, and not in a freon leak or a malfunction of the motor-compressor. Correct adjustment can extend the life of the unit and return it to normal operation without expensive repairs at a service center.
Operating principle and design of the K59 thermostat
Series thermostat K59 is an electromechanical device, the operation of which is based on a change in the volume of gas or liquid inside the bellows (sensitive element). When the temperature in the evaporator reaches a predetermined threshold, the pressure inside the bellows changes, which leads to mechanical opening of the contacts.
Inside the device housing there are contactswhich control the supply of voltage to the compressor. The most important element is a capillary tube, which is filled with a temperature-sensitive agent. It is this that transmits thermal vibrations from the evaporator to the switching mechanism itself.
The K59 design is reliable, but over time the springs can weaken and the contacts can burn. Understanding how this unit works will help you avoid mistakes when servicing it. Do not forget that there is refrigerant inside, so the tightness of the bellows is critical for correct operation.
How does K59 differ from other thermostats?
Thermostats of the K59 series have a specific length of the capillary tube and the location of the contacts, which makes them not always interchangeable with models of other series, for example TAM or ORD.
Fault diagnosis before adjustment
Before turning the adjusting screws, it is necessary to conduct a thorough diagnosis. Often, users try to adjust a working thermostat, although the problem lies elsewhere in the refrigeration circuit. The symptoms may be similar, but the solution methods are radically different.
Pay attention to the following signs that may indicate problems with the thermostat or adjacent components:
- 🔌 The compressor runs continuously without turning off, and the temperature in the chamber drops below normal.
- ❄️ The refrigerator does not turn on at all, although there is voltage in the socket and the light is on.
- 🌡️ The temperature regime “floats”: it is either too cold, or the food begins to thaw.
- 🔊 The relay clicks are heard, but the engine does not start.
If you observe constant operation of the motor, this may indicate that contacts it is stuck in a closed state or the calibration is broken. In the case when the equipment is silent, perhaps the circuit is open forever due to a breakdown of the internal mechanisms of K59.
Preparation for self-adjustment
To carry out work on adjusting the thermostat, you do not need complex professional equipment, but a basic set of tools is required. Safety is a paramount factor, therefore all manipulations are carried out only after the device is completely disconnected from the power supply.
You will need the following tools and materials:
- 🔧 A set of screwdrivers (phillips and flat) for dismantling the panels.
- 🌡️ External thermometer to monitor the temperature inside cameras.
- 🧤 Protective gloves for working with sharp edges and cold surfaces.
- 🔦 Flashlight for better illumination of the interior space.
Before disassembling, make sure that you know exactly the location of the thermostat K59 in your refrigerator model. It is usually located inside the refrigerator compartment, behind a plastic panel or in the control unit. In some models, access to the adjustment screw is possible without completely disassembling the case.
⚠️ Attention: Before removing any panels, be sure to wait until the refrigerator defrosts if there is ice on the evaporator. An attempt to pick out a frozen part can lead to a rupture of the capillary tube of the thermostat, which will make it unsuitable for repair.
Step-by-step instructions for adjusting the temperature
The process of adjusting the thermostat K59 requires care and precision. The basic adjustment is made by rotating a special adjustment screw, which changes the tension of the spring inside the mechanism. This tension determines the force required to open the contacts.
Perform the steps in the following sequence:
- Provide access to the thermostat by removing the protective plastic cover or decorative trim.
- Find a small hole on the device body or protruding screw. It is often marked with paint or a seal.
- Use a thin screwdriver to turn the screw. Turning clockwise generally increases increases the tension on the spring, increasing the cut-off temperature (the refrigerator will turn off at a higher temperature).
- Turning counterclockwise loosens the spring, causing the compressor to turn off at lower temperatures ("extreme cold" mode).
It is important to turn the screw literally half a turn or even less, and then let the refrigerator run a full cycle. Abrupt changes in settings can lead to incorrect operation of the system.
☑️ Setting algorithm
Temperature control and testing
After making changes to the thermostat settings K59 it is impossible to immediately confirm the success of the operation. It is necessary to conduct control testing, which will show how the operating parameters of the refrigerator have changed. This will require time and an external measuring device.
Place a regular household thermometer in a glass of water and place it on the middle shelf of the refrigerator. This will give a more accurate result than measuring air temperature. Start the refrigerator and wait for the first automatic shutdown of the compressor.
The optimal temperature in the main chamber should be in the range from +2 to +6 degrees Celsius. If the readings go beyond these limits, the adjustment procedure must be repeated by making another slight turn of the screw in the desired direction.
| Parameter | Normal value | Action upon deviation |
|---|---|---|
| Temperature in the chamber | +2...+5 °C | Adjust with screw |
| Temperature difference | No more than 2-3 °C | Check loading |
| Compressor operating time | 30-40% of the cycle | Check tightness |
| Evaporator temperature | -18...-24 °C | Setting K59 |
Typical mistakes when setting up K59
Independent adjustment of the thermostat involves the risk of making mistakes that can aggravate the situation. Beginners often try to compensate for the lack of cold by tightening the screw as much as possible, without understanding the physics of the process.
One of the common mistakes is ignoring the condition capillary tube. If it is not laid correctly or is bent, the thermostat will read incorrect data, and no adjustment with the screw will help. The tube should fit tightly to the evaporator at the point of attachment.
Also, do not forget about the influence of the environment. If the refrigerator is located next to a radiator or is exposed to direct sunlight, the thermostat will operate abnormally. In such cases, adjusting K59 will only give a temporary effect.
⚠️ Attention: Never use excessive force when rotating the adjustment screw. The mechanism is K59, and thread breakage or breakage of the plastic rod will lead to the need to completely replace the unit.
When adjustment is useless and replacement is needed
There are a number of situations when attempts to adjust the thermostat K59 become meaningless. If the internal contacts are completely burnt out or oxidized to the point of lack of conductivity, mechanical adjustment will not restore the electrical circuit.
Signs indicating the need for replacement:
- 🚫 Complete lack of response to turning the temperature regulator on the control panel.
- ⚡ Visible traces of melting or sparking inside the thermostat housing.
- 📉 Inability to start the compressor even when the contacts are closed directly (checking the motor).
- 💧 Violation of the tightness of the bellows (leakage of filler gas).
In such cases, the only right decision will be to buy a new analogue. When choosing, pay attention to the markings, the length of the capillary tube and the size of the contacts. There are no universal solutions here; each type of K59 has its own characteristics.
Where can I find the markings?
The model and parameters of the K59 thermostat are usually stamped on a metal plate attached to the body of the device, or painted on the side edge.
Is it possible to adjust the thermostat K59 without disassembling the refrigerator?
In some refrigerator models, access to the K59 thermostat adjustment screw is possible through special technological holes in the plastic control panel. However, in most cases, for precise adjustment and diagnostics, partial disassembly is required in order to visually monitor the condition of the contacts and the position of the capillary tube.
How often should the thermostat be adjusted?
During normal operation of the refrigerator, adjustment of the K59 thermostat is required extremely rarely, usually only after replacing the unit itself or in case of obvious malfunctions. If you have to tighten the screw every few months, this is a sign of a more serious problem in the refrigerant system or insulation.
What should you do if the refrigerator runs longer after an adjustment?
An increase in the compressor operating time after an adjustment may be a consequence of the fact that you lowered the shutdown temperature too much. Try turning the screw a few times in the opposite direction. If the situation does not change, check the tightness of the doors and the condition of the seals.
Does the room temperature affect the operation of the K59?
Yes, the K59 thermostat, like any electromechanical device, depends on external conditions. In a very hot room, the refrigerator will work longer, trying to reach the set temperature, and in a cold room it may not turn on at all if the ambient temperature drops below the minimum operating threshold.
Is it safe to change the thermostat settings yourself?
Adjusting the screw is safe if you follow electrical safety rules and disconnect the device from the mains. However, inappropriate intervention may disrupt the factory calibration. If you are not sure of your actions, it is better to contact a specialist, since incorrect settings can lead to food spoilage or compressor failure.