The situation when the Biryusa refrigerator stops turning off or, conversely, stops freezing to the desired temperature, often indicates a thermostat malfunction. This small but critical element is responsible for maintaining the microclimate inside the chambers by opening and closing the electrical circuit depending on the sensor readings. Owners of units that are several years old sooner or later have to face the need to replace this part, since the life of its mechanical parts is not endless.
Replacing the thermostat yourself is a very real task for a person who has basic skills in working with tools and understands the basics of electrical safety. The main advantage of such repairs is saving money: calling a specialist and paying for his work often constitute a significant part of the cost of a new spare part. However, for the process to be successful, it is necessary to clearly understand the structure of the unit and strictly follow the sequence of actions, otherwise you can damage the control system or get injured by electric shock.
In this article we will look in detail at how to diagnose a breakdown, which thermostat to choose for your Biryusa model and how to properly dismantle the old regulator and install a new one. We will look at the features of various modifications, from classic models with a crying evaporator to modern No Frost systems, so that you can carry out repairs accurately.
Diagnostics of thermostat malfunction
Before disassembling the refrigerator, you need to make sure that the problem lies in the thermostat, and not in the compressor or freon leak. Thermoregulator is an electrical switch that trips when a certain temperature is reached. If it is stuck in the “on” position, the compressor will work continuously, freezing the food to the point of stone, and a thick layer of ice will form on the walls of the chamber. If the contacts open and do not close, the motor simply will not start and the chamber will become warm.
There is a simple method of initial testing that does not require complete dismantling of the unit. To do this, you need to find the capillary tube (it comes out of the thermostat housing) and lower it into a glass of water at room temperature. If after a few minutes you do not hear the characteristic click of the contacts opening, then the thermostat is faulty. However, this method only works for extracted parts, so often craftsmen go by excluding other breakdowns.
- 🔍 The compressor hums continuously, without turning off for hours, and the temperature in the chamber drops below -20°C.
- 🔍 The refrigerator is silent, the light is on, but the motor does not start even after defrosting for days.
- 🔍 Not uniform frost forms on the back wall of the refrigerator compartment, but a huge “coat” that does not melt during the defrost cycle.
It is also important to check the integrity of the capillary tube. If there are traces of oil or mechanical damage on it, the tightness of the system is broken and the filler gas (usually freon or freon) has evaporated. In this case, replacing the thermostat it will not help - you will need a new sensor assembled with a tube. It is also worth paying attention to the condition of the contacts: if they are burnt, the resistance of the circuit will increase, which will lead to incorrect operation of the automation.
⚠️ Attention: Before starting any diagnostics, be sure to disconnect the refrigerator from the power supply! Working with live electrical appliances is strictly prohibited and dangerous to life.
Choosing suitable spare parts for Biryusa models
Biryusa refrigerators have been produced for several decades, and during this time various types of thermostats have been installed in them. The most common are mechanical thermostats, which are divided into single-chamber and double-chamber. For classic models with a single chamber or a “crying wall” system, TAM or K-59 series regulators are often used. In two-chamber units with a separate freezer compartment, more complex devices are used, such as TAM-133 or imported Danfoss analogues.
When choosing a new part, it is critical to consider the length of the capillary tube. Standard sizes range from 0.6 to 2.5 meters. If the tube is too short, you will not be able to position the sensing element correctly in the evaporator. If it is too long, you will have to carefully roll it into a ring, making sure not to pinch or damage the thin metal.
Below is a table of correspondence between popular models of Biryusa refrigerators and the thermostats used in them:
| Refrigerator model | System type | Recommended thermostat | Tube length (approximate) |
|---|---|---|---|
| Biryusa 6, 8, 10 | Single chamber | TAM-112, K-50 | 0.6 - 0.8 m |
| Biryusa 133, 134 | Two-chamber | TAM-133, K-59 | 1.2 - 1.5 m |
| Biryusa 355, 455 | No Frost | TAM-133 (freezer) | 1.5 - 2.0 m |
| Biryusa 490 | No Frost | K-59 L1188 | 2.0 - 2.5 m |
| *Data may vary depending on the year of manufacture and modification. | |||
When purchasing, pay attention to the contact markings. They are usually designated by the numbers 3, 4, 6 or the letters L, C, N. Incorrect connections can lead to a short circuit or the compressor bypassing the thermostat. It is also worth purchasing a new capillary complete set if the old one has traces of corrosion, even if it is intact.
Necessary tools and workplace preparation
For a high-quality replacement of the thermostat, you will need a minimum set of tools that any home craftsman can find in his home. The main tool will be a Phillips and flathead screwdriver, since the mounting screws in Biryusa refrigerators can be of different types. You will also need a multimeter (tester) to check the circuit and insulating tape or heat shrink to protect the contacts.
Particular attention should be paid to the organization of lighting. The inside of the refrigerator, especially the evaporator area and the rear wall, are often poorly lit. Using a headlamp or a powerful lamp on a tripod will allow you to see small parts and avoid damaging the plastic latches during disassembly. The workplace should be dry and free from foreign objects.
- 🛠️ Set of screwdrivers (phillips, flat, possibly slotted).
- 🛠️ Multimeter for checking the electrical circuit (testing mode).
- 🛠️ Pliers with thin jaws for careful removal of the tube.
- 🛠️ Insulating tape or cambrics for insulating connections.
Be sure to defrost the refrigerator before starting work. Even if you are only replacing the thermostat, ice on the evaporator can make the capillary tube difficult to access and may damage it when removed. Leave the unit turned off for at least 12 hours so that all the ice melts and the water runs out.
☑️ Preparation for repair
Removing the old thermostat
The process of removing the old temperature controller depends on the design of your Biryusa model. In most cases, the thermostat is located inside the refrigerator compartment in a plastic case or behind a decorative panel. First, you need to remove the regulator handle (if it protrudes outward) and unscrew the screws securing the housing to the chamber wall.
After removing the casing, you will see the thermostat itself with the wires approaching it and the capillary tube going deep into the housing. Dismantling requires caution: first, the electrical wires are disconnected. It is recommended to take a photo of the connection diagram or mark the wires with a marker so as not to mix up the contacts during assembly. Then the capillary tube is carefully pulled out from the technological hole in the evaporator.
If the tube is stuck or stuck, do not use excessive force. Thin metal breaks easily. You can slightly warm up the exit point of the tube with a hairdryer (not a hair dryer, but a regular one at a minimum temperature) to soften any possible ice or plastic. In models with the system No Frost access may be complicated by the presence of air ducts, which will also have to be dismantled.
⚠️ Attention: The capillary tube is very thin and fragile. If it is damaged and gas leaks from the bellows, the thermostat will become inoperative immediately after installation.
Installation of a new thermostat and connection
Installation of the new device is carried out in the reverse order of dismantling. First of all, the new capillary tube is carefully inserted into the opening of the evaporator. The immersion depth should correspond to the length of the old tube or the manufacturer's recommendations (usually 10-15 cm). It is important to avoid creases and kinks in the tube, as this will disrupt the transmission of gas pressure to the membrane.
The next step is the electrical connection. Using the notes you made earlier or a diagram, connect the wires to the terminals of the new thermostat. For reliability, the contacts can be lightly cleaned and soldered, although in the factory version they usually just sit tightly in the terminals. After connecting, be sure to “ring” the circuit with a multimeter: at room temperature, the contacts should be closed (if it is not a specific breaker), and when cooled, they should open.
The fixation of the thermostat housing in the seat should be tight. Vibration from a running compressor should not be transmitted to the sensitive element, so use standard rubber gaskets or seals. If the new thermostat comes with additional insulation for the tube, be sure to use it to avoid false alarms from the heat coming from the walls of the chamber.
Setting up and testing the operation of the refrigerator
After assembling all the components and connecting the refrigerator to the network, do not rush to load the products. The initial start-up should be idle. Set the thermostat knob to the middle position (usually number 3 or 4). After 10-15 minutes of operation, the compressor should turn off, and after a while (depending on the differential setting) it should turn on again.
Check the door for tightness and the absence of extraneous noise. If the refrigerator is operating normally, you can perform a freezing test. Load the chamber with a small amount of food and leave for 4-6 hours. The temperature in the main chamber should stabilize within +2...+5°C, and in the freezer - no higher than -18°C.
If you observe “underweight” or “overheating,” additional adjustment may be required. Some models of thermostats have an adjustment screw, access to which is sealed or located inside the housing. Rotating this screw changes the on/off temperature. However, for household Biryusa models such fine tuning is rarely required; usually the factory settings are sufficient.
What to do if the refrigerator does not turn off after replacement?
If the compressor runs continuously for more than 2 hours and does not turn off, check whether the capillary tube is installed correctly. Perhaps it does not reach the cold zone or, on the contrary, is pressed against a warm wall. Also check if the contacts are mixed up (for example, a pass-through contact is connected instead of the main one).
Can I use a thermostat from another refrigerator?
The use of analogues is possible, but only if the basic parameters match: temperature range, capillary tube length and contact type. Thermostats from different manufacturers (for example, TAM instead of K-59) may have different sensitivity, which will lead to incorrect operation.
Why does the new thermostat click, but the compressor does not start?
This may indicate a malfunction of the compressor starting relay or the motor itself. It is also possible that during replacement the contacts were poorly cleaned or the power supply circuit was broken. Check the voltage at the input to the compressor at the moment of click.
How often do you need to change the thermostat in the Biryusa refrigerator?
The service life of a mechanical thermostat is on average 5-7 years of active use. However, if there are power surges in the network or frequent defrosting, it may fail earlier. Planned replacement is not required, only after a breakdown.
Is it dangerous to change the thermostat yourself?
If electrical safety rules are observed (mandatory disconnection from the network), the procedure does not carry critical risks. The main danger is to damage the capillary tube of the evaporator if removed carelessly, which will require professional repairs with refilling with freon.