A sudden increase in temperature in the refrigerator compartment often becomes an unpleasant surprise, especially when food begins to deteriorate. Refrigerators Biryusa are famous for their reliability, but over time, even time-tested mechanical components fail. Most often, the culprit of unstable operation is the thermostat, which ceases to respond correctly to changes in temperature inside the chamber.
Independent replacement of this unit is a completely doable task for a person who knows how to hold a screwdriver in his hands and understands the basics of electrical circuits. However, in this article we will analyze the process of diagnostics, dismantling the old one and installing a new temperature controller, paying special attention to the nuances specific to the equipment of this brand.
Do not panic if the refrigerator stops turning off or, conversely, does not start the compressor at all. Thermostat is a consumable item, the resource of which is limited by the number of on and off cycles. A correctly selected replacement and proper installation will allow the unit to return a second life without an expensive service visit.
Diagnostics of a thermostat malfunction
Before disassembling the equipment, you need to make sure that the problem lies in the temperature sensor. Symptoms of failure can be different: from continuous operation of the compressor to complete failure of the refrigeration chamber to cool. If the motor hums constantly and does not turn off, and the temperature drops below normal, the food freezes at the back wall, this is a sure sign that the contacts inside the regulator are stuck in a closed state.
In the opposite situation, when the compressor is silent, but it is warm inside, it is possible that the thermostat simply does not close the circuit. For an initial check, you can try to forcefully close the contacts at the terminals, having first disconnected the device from the network. If after this manipulation the refrigerator starts, then the problem is definitely in the sensor. However, this method requires caution and understanding of the electrical circuit.
The most accurate way to check is to use a multimeter in continuity mode. At room temperature, the contacts should be closed (unless it is a specific normally open sensor, which is rare for the main camera). If the circuit does not break when the sensitive tube is cooled (for example, in a glass with ice), the part requires replacement.
- ❄️ The compressor works non-stop, forming ice on the back wall.
- 🔌 The refrigerator does not turn on, although the light inside is on.
- 🌡️ The temperature in the chamber does not correspond to the set position of the handle.
- 🔊 A characteristic click is heard, but the engine does not start.
⚠️ Attention: Before starting any work on diagnosing and replacing components, be sure to disconnect the refrigerator from the power supply. Working with 220V voltage without the appropriate skills and tools is life-threatening.
Choosing a suitable thermostat model
The spare parts market offers many analogues, but for refrigerators Biryusa it is critical to choose a device with the correct response parameters. The thermostats of the TAM or K50 series are most often used in these units. For example, model TAM-133 or K-59 L1136 is often found in two-chamber models, while other modifications can be used for single-chamber options.
The key parameter is the length of the capillary tube. Standard sizes range from 0.75 meters to 3 meters. If you install a thermostat with a tube that is too short, it simply will not reach the required location in the evaporator, and temperature control will be incorrect. A tube that is too long can be neatly rolled up, but this requires space for installation.
Also pay attention to the presence of a third terminal. It is designed to connect an indicator light or fan (in models with No Frost). If your refrigerator does not have such a function, the terminal will be free, and you can use an analogue without a third contact, if it structurally fits the seat.
| Thermoregulator model | Capillary tube length | Type of contacts | Application |
|---|---|---|---|
| TAM-133 | 0.75 m | 2 contacts | Single-chamber refrigerators |
| K-59 L1136 | 1.3 m | 3 contacts | Two-chamber Biryusa models |
| TAM-145 | 2.5 m | 3 contacts | Freezers |
| K-50 L1136 | 0.75 m | 2 contacts | Budget models |
Where can I find the markings of an old thermostat?
The markings are usually applied to the metal body of the device. To see it, you often have to remove the plastic casing or remove the assembly from its seat. Look for a code starting with TAM, K-59, K-50 or similar.
Preparing tools and workplace
For successful replacement thermostat you will need a minimum set of tools. The main ones will be Phillips and flat screwdrivers, since fastening screws in refrigerators can be of different types. Also, do not forget to prepare a multimeter for the final check of the circuits before assembly. Biryusa may be of different types. Also, don't forget to have a multimeter ready for a final check of the circuits before assembly.
The workplace should be well lit. It is recommended to move the refrigerator away from the wall, allowing access to the rear if the compressor needs to be checked, although replacing the thermostat is usually done from the refrigerator compartment. Prepare a container for defrosting in advance if a long shutdown is required during the process.
☑️ Tools for replacement
The process of dismantling the old regulator
The removal process begins with freeing access to the thermostat. In most models Biryusa it is hidden under a plastic cover or located inside the lampshade. Carefully pry up the plastic latches with a screwdriver, being careful not to break them, as plastic becomes brittle over time.
After removing the decorative panel, you will see the regulator handle. It can fit tightly, sometimes even with glue or a retainer. Remove the handle by pulling it towards you and unscrew the screw that is located under it. This will free the thermostat housing itself.
The most important thing is to carefully remove the sensitive tube. It is fixed in a special hole and pressed against the evaporator. Do not pull the tube forcefully to avoid damaging its thin walls. First unscrew the mounting plate, then carefully pull the tube out of the process channel. If the tube is wrapped around the evaporator, unwind it gradually.
Disconnecting the wires is the final stage of dismantling. Before doing this, be sure to take a photo of the connection diagram or sketch it, since the colors of the wires may differ in different years of manufacture. Typically, terminal clamps are used that just need to be released.
⚠️ Attention: The capillary tube of the thermostat is filled with freon under pressure. When removing, avoid sharp bends and impacts. Damage to the tube will lead to failure of the new sensor immediately after installation.
Installation and connection of a new thermostat
Installation of the new device is carried out in the reverse order of dismantling. Start by laying out the capillary tube. Insert it into the same hole from which the old one was removed, and secure the end of the tube to the evaporator using a standard clamp. Press the tube tightly against the surface of the evaporator - the accuracy of temperature reading depends on this.
Connecting the electrical part requires care. If you didn't take pictures of the wires, use the color coding of the terminals on the new device. Typically the terminals are numbered or have letters. Insert the wires into the appropriate sockets until they click.
Install the thermostat housing into the seat and secure it with a screw. Put on the adjustment knob. Make sure the handle rotates freely and does not get stuck in its extreme positions. After this, you can assemble the plastic lining.
The final touch will be to check the tightness and reliability of the fasteners. Make sure that no wires are pinched by the refrigerator body or door. All plastic elements must fall into place without gaps.
Setting up and checking operation
After assembly, turn on the refrigerator. The initial launch may take some time. Let the unit run for at least 30-40 minutes so that the temperature inside the chamber stabilizes. At this point, do not open the door frequently so as not to disturb the cooling process.
Checking the cyclic operation is the main stage of testing. The compressor should turn on, cool the chamber to the set temperature and turn off when the thermostat clicks. If the refrigerator has turned off, but the temperature is still high, adjustment may be required.
Adjustment is made using a special screw, which is often located inside the hollow thermostat knob or under a seal on the case. Turning the screw clockwise usually increases the shutdown temperature (the compressor will turn off earlier), and counterclockwise - lowers it (the refrigerator will freeze more).
- 🕒 Let the refrigerator operate for 2-3 hours to reach the mode.
- 🌡️ Use a separate thermometer to control the actual temperature.
- 🔊 Listen to the moment the compressor turns off - it should be clear.
Possible problems after replacement
Sometimes after replacing a unit, nuances arise that require additional attention. If the refrigerator begins to cycle in short cycles (turning on and off frequently), this may indicate that the sensing tube is not in the correct position. Check the tight fit of the tube to the evaporator.
If the compressor hums but does not start, or immediately knocks out the circuit breaker, the problem may be in the start relay, which could have been damaged by power surges during diagnostics. It is also worth checking the integrity of the wires going to the compressor.
If you replaced the thermostat with an analogue one with different characteristics (for example, with a lower shutdown temperature), the refrigerator may freeze more than usual. In this case, only repeated replacement with a model with the correct range or fine tuning with the adjustment screw will help, if the range allows.
⚠️ Attention: If after replacing the thermostat the refrigerator continues to work incorrectly, do not rush to blame the new part. Perhaps there is a freon leak in the system or the compressor is faulty, and replacing the sensor only temporarily changed the nature of the operation.
Is it possible to use a thermostat from another brand?
Yes, you can if the dimensions, tube length and temperature range match. The main thing is that the contacts open and close at the same temperatures as the original.
Common mistakes during self-repair
One of the most common mistakes is neglecting the length of the capillary tube. Craftsmen often buy the first thermostat they come across, not paying attention to the length markings. As a result, the tube either does not reach the attachment point, or it has to be pushed in with force, which leads to creases and loss of sensitivity.
Another mistake is poor contact of the tube with the evaporator. If the tube is simply inserted into the hole, but not pressed down with a metal bar, it will measure the temperature of the air in the chamber, and not the temperature of the evaporator. This will lead to large delays in the reaction and temperature changes.
Grounding is also often forgotten. The thermostat housing is metal and can come into contact with the internal parts of the refrigerator. Make sure that the grounding wire (if it was) is connected correctly to avoid electric shock when touching the case.
How to understand that the thermostat needs to be changed and not repaired?
Mechanical type thermostats are sealed units. It is useless to open them and try to clean the contacts, since the calibration and tightness of the bellows will be disrupted. The only solution is to completely replace the part.
Why does the Biryusa refrigerator freeze too much even at minimum?
This may indicate that a thermostat is installed with an inappropriate range (too “cold”), or the damper is faulty (in two-chamber models), or a refrigerant leak has occurred, which is why the compressor runs non-stop, trying to gain temperature.
How much does it cost to replace a thermostat in a service?
The cost consists of the price of the spare part itself (usually from 500 to 1500 rubles) and the work of a specialist (from 1000 to 2000 rubles). Self-replacement allows you to save on the cost of work, but requires time and accuracy.
Do you need to defrost the refrigerator before replacing?
Full defrosting is not necessary if access to the thermostat is from the side of the refrigerator compartment. However, if ice prevents you from reaching the fasteners or there is a risk of water getting on the electrical contacts, it is better to let the refrigerator stand turned off for several hours.
Can the thermostat fail due to a power surge?
Yes, although this happens less often than mechanical wear of the contacts. A powerful surge in voltage can cause sparking between the contacts, which will lead to their welding (sticking) or, conversely, the formation of carbon deposits that prevent the passage of current.