Failure of the cooling system often becomes an unpleasant surprise for owners of household appliances. Products begin to deteriorate faster, and ice appears on the walls of the chamber or, conversely, frost disappears. In many cases, the root of the problem lies in the incorrect operation of thermostatwhich is responsible for turning the compressor on and off.
The thermostat of the model K-59 is one of the most common components in refrigerators in the mid-price segment. Its correct operation ensures stable temperature conditions necessary for long-term food storage. If you notice that the equipment works without interruptions or turns off too often, intervention in the settings is required.
In this material we will look at how to independently diagnose the adjustment device. You'll learn what tools you'll need, how to interpret the readings, and when a complete element replacement will be necessary. Proper adjustment will extend the life of the compressor and save energy.
Principle of operation and design of the K-59 thermostat
Thermostat K-59 is an electromechanical device that responds to changes in temperature in the refrigeration room camera. Inside the housing there is a sealed system filled with freon or other refrigerant. When the sensitive element is heated or cooled, the pressure inside the system changes, which leads to the opening or closing of electrical contacts.
The key element of the design is capillary tube, which is attached to the evaporator. It is this that transmits thermal vibrations to the thermostat bellows. The K-59 model is usually equipped with three contacts, which allows you to control not only the compressor, but also the indication lamp or the defrost system in some modifications.
⚠️ Attention: Before any intervention in the electrical circuit of the refrigerator, be sure to disconnect the device from the network. Working with 220V voltage without proper training is life-threatening.
Understanding the device helps to avoid mistakes during setup. If the mechanism jams or the contacts burn out, simple adjustment with a screw will not help - you will need repair or replacing the unit. However, in most cases, the failure is caused by broken factory parameters.
Diagnostics of faults before tuning
Before taking a screwdriver, you need to make sure that the problem is in the thermostat, and not in a freon leak or a compressor malfunction. Primary diagnosis takes a little time, but allows you to avoid unnecessary steps. If the refrigerator does not turn on at all or hums constantly without turning off, these are the first signs.
Check the condition of the contacts and the integrity of the capillary tube. Mechanical damage often leads to gas leakage from the bellows, after which the thermostat stops responding to temperature. It is also worth inspecting the place where the tube is attached to the evaporator - if it comes loose, the readings will be incorrect.
For an accurate check, you can use a multimeter in dial mode. At ambient temperatures the contacts must be closed. If you place the sensing element in the cold (for example, in the freezer for 10-15 minutes), the circuit should break. Lack of response indicates the need for replacement parts.
Preparation of the tool and workplace
Quality adjustment is impossible without proper preparation. You will need to provide access to the thermostat, which may be located differently in different refrigerator models. Usually it is hidden under a plastic panel inside the chamber or behind the back cover of the unit.
For work you will need a minimum set of tools. It is important that they are all in working order and at hand so as not to interrupt the work process. It is also recommended to prepare a clean rag for wiping the contacts from dust and oxides.
☑️ Tools for adjustment
Pay special attention to lighting. Working with small parts in the dark interior of a refrigerator is difficult and unsafe. Use a flashlight or portable lamp to clearly see the markings of the wires and the position of adjusting screws.
Step-by-step instructions for adjusting the temperature
The adjustment process depends on what kind of problem is observed: the refrigerator does not gain cold or, on the contrary, it overcools the food. Adjustment is carried out by rotating a special screw located on the thermostat body or on the control knob.
If you want to change the temperature on of the compressor, act on one screw, and if the temperature off - on another. The K-59 model often uses a single mechanism, where turning the axis changes both parameters, but with a different range.
⚠️ Attention: Do not make sharp turns of the adjusting screw. Changing the settings should occur smoothly, in increments of no more than half a turn at a time.
For precise adjustments, use an external thermometer placed in a glass of water in the center of the chamber. This will give an objective picture, since the built-in sensors can show the temperature of the air, and not the products.
The subtleties of setting the differential
The thermostat differential is the temperature difference between turning the compressor on and off. For the K-59, a range of 2-4 degrees is considered normal. If the spread is too large, food may defrost in idle cycles.
After each change in screw position, you must allow the refrigerator to run a full cycle. This may take from 30 minutes to several hours. Only after automatic shutdown and restart can you evaluate the result and make further adjustments.
Table of typical K-59 settings
For the convenience of masters and users, there are recommended factory settings. They serve as a reference point if the device has been completely dismantled or replaced with a new one. Deviations are acceptable, but must be justified by operating conditions.
| Parameter | Value | Unit of measurement | Comment |
|---|---|---|---|
| Switch-on temperature | -5...-8 | °C | Depends on the position of the handle |
| Switch-off temperature | -18...-22 | °C | For freezer compartment |
| Differential | 2...4 | °C | Temperature difference |
| Operating pressure | 4.6...5.0 | Bar | At the moment of shutdown |
These values are relevant for standard operating conditions. If the refrigerator is located in an unheated room or near heat sources, the parameters may require adjustment. In such cases, it is better to shift the range towards lower temperatures.
Replacing the thermostat: when adjustment does not help
There are situations when twisting the screws does not produce results. If the contacts are burnt, the bellows has lost its seal or the rod is jammed, adjustment is useless. In this case, it is necessary to replacement a thermostat with a similar one.
When choosing a new part, it is important to pay attention not only to the model, but also to the length of the capillary tube. A tube that is too long can be carefully rolled into a ring, but a short one cannot be extended. Also check the number of contacts - there should be the same number as on the old device.
The replacement process takes about 30-40 minutes. After installing a new element, be sure to carry out the initial setup procedure described above, since the factory parameters of the new thermostat may differ from the old one.
Common mistakes during self-repair
Beginners often make typical mistakes that can lead to compressor breakdown or food damage. One of the most common is trying to adjust the temperature with the door open. In this case, the sensor does not see the real cold in the chamber.
Another mistake is ignoring the condition of the door seal. If warm air enters through the cracks, the thermostat will constantly keep the compressor on, and no adjustment will correct the situation. First, eliminate leaks, then adjust the equipment.
- 🔧 Attempting to adjust without taking readings with an external thermometer.
- 🔧 Turning the screw more than one turn without waiting for the system to react.
- 🔧 Ignoring ice on the evaporator, which distorts heat transfer.
- 🔧 Using dirty tools, which can lead to a short circuit.
Be attentive to details. Thermoregulator K-59 is a reliable unit, but it requires careful handling. If you are not confident in your abilities, it is better to call a specialist, since incorrect settings can lead to water hammer in the compressor.
⚠️ Attention: Thermostat characteristics may vary slightly depending on the year of manufacture and the specific manufacturing plant. Always check the technical documentation of your refrigerator model before starting work.
Questions and answers (FAQ)
Is it possible to use a K-59 thermostat instead of a K-50?
In most cases, this is possible, since they have similar characteristics, but may differ in the length of the capillary tube and temperature range. Before installation, carefully compare the markings and parameters of both devices.
Why did the refrigerator start working longer after adjustment?
Most likely, you changed the shutdown threshold to a lower temperature. The compressor takes longer to cool the chamber to the set point. If the food does not freeze, this is normal.
How to understand that the K-59 thermostat is completely faulty?
If, when tested with a multimeter, the contacts do not change their state when the sensitive element is cooled and heated, or if traces of melting of the housing are visible, the part must be unconditionally replaced.
Is it necessary to defrost the refrigerator before making adjustments?
Yes, complete defrosting and drying of the chamber is required. This will allow you to get accurate thermometer readings and protect you from working with electricity in a humid environment.