Temperature regulator for the refrigerator: device, check + subtleties of replacement if necessary
It is difficult to imagine your life without household appliances. There are devices that we could do without, and there are those without which the arrangement of living space is justifiably considered inferior. One of such vital items is a refrigerator. Do you agree?
DIY repair of household appliances is a good help for the family budget. If desired, you can master many repair operations. For example, replacing a thermostat for a refrigerator is not so difficult. One has only to understand the design features and principles of the device.
We will talk about how to detect a malfunction of the thermostat. Our proposed article describes in detail how to replace it during the repair of a Stinol brand refrigerator. Information is accompanied by a thematic selection of photo and video materials with expert advice.
The content of the article:
- Design features and operating principle
- Ways to Detect a Problem
- Thermal Relay Dismantling Rules
- Replacement on the example of the Stinol refrigerator
- Conclusions and useful video on the topic
Design features and operating principle
A temperature regulator or thermostat is one of the main elements without which the normal operation of the refrigerator is impossible. It captures the temperature sensors in the refrigerator and freezer and sends a signal to the compressor start relay.
In accordance with these signals, the compressor turns on if the chamber is not cold enough, and turns off when the temperature reaches a predetermined level. Technically, a thermostat is a relay, at one end of which there is a sealed tube filled with freon.
On the other hand, contacts are installed, the opening and connection of which sends a signal to the compressor. The end of the freon tube, also called the capillary tube, is fixed to the evaporator.
The refrigerant placed inside reacts sensitively to heating and cooling. When the temperature decreases or rises, the pressure level inside the tube changes, as a result of which the relay contacts are connected or opened.
The movement of the contacts is controlled by a small spring. It is used to set the temperature level that should be inside the refrigerator compartment. A temperature adjustment knob is attached to the spring. Turning this knob changes the degree of spring tension.
As a result, more or less force is required to close and open the contacts. This affects the pressure level in the capillary tube at which the contacts are triggered.
This regulates the degree of air cooling in the refrigerator. When using an electronic controller, this process is carried out in a slightly different way, but the principle remains approximately the same: the desired temperature level is set based on the actual indicators that the capillary tube fixes.
But such models use an electronic control module that can simultaneously manage data from several sensors. It is not always possible to repair or replace such a thermostat at home. To handle complex electronics, you need knowledge and special equipment.
Typically, a thermostat is installed inside or outside the refrigerator. Before starting repairs, it’s good to study refrigerator device and device data sheet. There can be a lot of useful information on the design of a specific model of a temperature controller, as well as on its location.
Usually a thermal relay is located next to the knob for setting the temperature mode. The internal arrangement is typical for relatively old models. Inside the chamber, the element is usually enclosed in a plastic protective case.
The adjustment knob is located directly on it. To remove the thermal relay, you need to remove this knob and unscrew the fixing screws to remove the case.
But you need to look for the thermostat also near the control knob, usually under the refrigerator case somewhere above. The handle is removed in the same way, the fasteners are unscrewed and the desired one is found behind the protective panel.
Ways to Detect a Problem
If the thermal relay is broken, this does not mean that the entire refrigeration unit will immediately stop working. But the lack of correct information about the current temperature will affect his work.
Option # 1 - check the functioning of the equipment
Symptoms of improper operation of refrigeration equipment can be as follows:
- the compressor works without interruptions or with very short and rare interruptions;
- the temperature inside the refrigerator’s chamber drops to zero, and sometimes even lower;
- a large amount of frost or even ice appears on the walls;
- the inside of the refrigerator is too warm;
- the refrigerator does not turn on after shutdown, etc.
Of course, these signs can be associated not only with breakdowns of the thermal relay, but also with malfunctions of other elements.
Option # 2 - diagnostics using a thermometer
To do this, completely disconnect the refrigerator from power, and then carry out its full defrosting in accordance with the instructions. Of course, the contents will have to be taken out.
After that, you need to turn on the device in the network and move the temperature control knob to a position that will allow you to get the lowest possible temperature. If the refrigerator model has a freezing mode, it is recommended to use it.
In the refrigerator compartment, approximately in the middle, you need to put a thermometer designed to measure air temperature. It is better to use a device that allows you to take measurements below zero. The refrigerator is left in this mode for about two hours. After that, you need to check the thermometer.
If the temperature in the refrigerator has dropped to about six degrees by this time, there is no problem with the thermostat. But when the inside has become noticeably warmer or colder than this level, the thermal relay will have to be replaced.
Option # 3 - visual inspection of the refrigerator compartment
If after thawing the so-called snow cap forms very quickly inside the camera, the initial diagnosis of the health of the thermostat can be performed very simply.
To do this, at the time of compressor operation, the adjustment knob begins to be turned in the direction of increasing temperature inside the chamber. If the relay is working properly, at some point the sensors will record the desired temperature level, after which the compressor will shut off. If the engine continues to work, the temperature controller must be changed.
After such a diagnosis and with a good thermal relay, it is recommended to remove all contents from the camera and allow the device to idle for about six hours. During this period, you need to pay attention to the duration of the breaks in the compressor.
If it is about 40 minutes, everything is fine, you can use the refrigerator in normal mode. If the compressor starts up too often or rarely, try to adjust this moment using the relay settings. If this fails, you will most likely have to install a new thermostat.
Thermal Relay Dismantling Rules
If the refrigerator does not turn on at all, it will be impossible to carry out the diagnostics described above. A possible cause of the breakdown is the failure of the electrics of this element.
But the problem can be compressor malfunctionfor example, a burned motor winding. To understand whether the thermal relay needs to be replaced, it will have to be removed from the refrigerator for research.
First you need to disconnect the refrigerator from the network. Now you should find the place where it is located, as described earlier. Usually you need to remove the adjustment knob, remove the fasteners and remove the protective elements.
Then you need to carefully inspect the device, paying close attention to the wires through which the power supply is connected.
All of them have different color markings depending on the purpose. Usually, a yellow wire with a green strip is taken for grounding. This cable should be left alone, but all the others should be disconnected and closed with each other.
Now the refrigerator is plugged in again. If the device still does not turn on, the thermostat is probably working, but there are serious problems with the compressor.
If the engine is running, you can make an unambiguous conclusion that the relay needs to be replaced. Before starting work, it will not hurt to arm yourself with a smartphone or camera to sequentially record all operations. When installing a new thermal relay, these images can be very useful, especially for beginners.
It is necessary to clearly remember which cable core was used for what purpose.Typically, a black, orange, or red wire is used to connect the thermal relay to an electric motor. A brown core leads to zero, a yellow-green wire provides grounding, and pure yellow, white or green is connected to a light indicator.
Sometimes it is not easy to remove a damaged regulator, especially when placed externally. For example, in some models of Atlant refrigerators it is necessary to completely remove the chamber door from the hinges. To do this, remove the overlay that is installed above the upper hinge and unscrew the bolts hidden beneath it.
Before you remove the adjustment knob, you also have to remove the plugs and unscrew the fasteners. All these operations must be done carefully. Fasteners and linings should be stored in a small container so that they are not lost. Actually the thermostat is usually screwed to the bracket, it must be carefully removed, unfastened and removed.
A new thermostat is installed in its place, adhering to the reverse assembly order. Sometimes the failure of the thermostat is associated with a malfunction of the so-called capillary tube or bellows. If you replace only this element, the relay can be left.
To perform this procedure, you will have to remove the thermal relay, adhering to the method described above. The bellows must be disconnected from the evaporator and carefully removed from the device. Now they install a new capillary tube, attach it to the evaporator, and the relays are mounted in the same place, and the disconnected wires are connected.
Replacement on the example of the Stinol refrigerator
For Stinol refrigerators relay failure is a fairly common occurrence, especially after five to seven years of operation.
Most often, a bellows tube breaks down here, since this is the option laid down by the manufacturer of this element. The Stinol-101 model has only one compressor, but in the Stinol-103 there are two of them: separately for the refrigerator and freezer.
The automation of different models is slightly different, which is reflected in the corresponding electrical circuits, otherwise these refrigerators are very similar, so it makes sense to consider the procedure for their repair at the same time.
To understand that a Stinol refrigerator needs to be repaired or replaced by a thermal relay, you need to pay attention to the following symptoms:
- the compressor runs non-stop and does not respond when the regulator is set to OFF;
- when translating the adjustment knob but the OFF mark, there is no characteristic click;
- the temperature in the refrigerator chambers significantly exceeds the parameters set during adjustment.
In the Stinol-103 refrigerator, the K-59 thermal relay is used, it is easy to check the marking, it is indicated on the case. To remove the adjustment knobs, you need to use a thin awl. They just need to pry and remove. The Stinol-101 has only one adjustment knob, and the Stinol-103 has two, one for each compressor.
After the handle is removed, you need to remove the decorative trim with six tabs. This is a fragile element, you should be careful not to damage it.Under the cover there are nuts that must be loosened. After that, you need to unscrew the screws that secure the control panel.
The screws that hold the hinge of the refrigerator door are best removed last. To avoid possible damage, the door must be held. Now you can lift the panel and remove the door from the hinges.
The next step is to remove the top cover of the refrigerator.
The necessary fasteners are located on the rear side. They are unscrewed and the cover removed. Thus, free access to the thermostat will be obtained.
First you need to disconnect the relay contact connectors, after which you can remove the element from the control panel of the refrigerator.
At this stage, you need to remember or record the color marking of the individual wires. To remove a worn capillary tube, remove the plastic overlay.
Now you need to unscrew the fixing screw and remove the lighting unit. The tube is removed through the hole provided for this.
The new element is installed so that the uninsulated portion in its lower part is securely hidden under the pad. The hole is closed with a plastic plug to restore the tightness of the chamber.
Typically, the capillary tube extends beyond the thermostat. It must be carefully placed under the top cover of the refrigerator, there is enough space there.
Now you need to reassemble the thermal relay and the refrigerator: connect all the necessary connections, install and fasten the lid of the refrigerator, hang the door.
And again, the fastening of the door hinge fasteners is performed last when the other similar screws are already installed.
To check the condition of the thermal relay of the Stinol refrigerator at home, you can use simple diagnostics. Contacts 3 and 4 of such a device should remain closed at room temperature.
If, after connecting them with a jumper, the compressor is turned on, the thermal relay is malfunctioning; If the thermostat settings are lost, they can be adjusted by turning the adjustment screws, but this should be done at a service center that has the necessary equipment.
An equally important functional unit in the design of the refrigerator is starting relay, with the device, the purpose and methods of repair of which will familiarize us with the article recommended by us.
Conclusions and useful video on the topic
The process of replacing the thermal relay is clearly demonstrated in the following video, in which the master shares the nuances of repairing refrigeration equipment such as Stinol:
Interesting tips for diagnosing the state of the relay and replacing it with the example of two models of refrigerators are contained in this video:
The procedure for replacing the thermostat cannot be called too complicated. However, improper handling of this element can only worsen the situation. A detailed study of the repair procedure and attention to detail will help restore the refrigerator.
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