Brand refrigerators Biryusa have earned a reputation as reliable equipment that can operate for many years without serious problems complaints. However, any mechanism tends to wear out, and the thermostat often becomes the most vulnerable element in the temperature control system. If you notice that the device began to “thresh” without interruption or, conversely, stopped gaining cold, most likely the problem lies in this particular part. Replacing the thermostat is a procedure that is accessible even to a technician with minimal experience, but requires attention to detail.
In models of the series Biryusa 22 and its modifications (for example, Biryusa 22 K), the design of the freezer allows you to gain access to the regulator without completely disassembling everything housings. This greatly simplifies the task for the home handyman. However, before starting work, it is necessary to clearly understand the structure of the unit so as not to damage fragile plastic or electrical contacts. Main task - correctly dismantle the old sensor and install a new one, maintaining the tightness of the system.
It is important to understand that a thermostat is not just a switch, but a complex mechanical device that responds to changes in freon pressure in the capillary tube. Incorrect installation or damage to this tube during removal will lead to refrigerant leakage, which will require professional intervention with soldering and refilling. Therefore, when starting work, act carefully and consistently, following a proven algorithm of actions.
Diagnostics of a thermostat malfunction
Before you grab a screwdriver, you need to make sure that the reason for the unstable operation of the refrigerator lies precisely in the thermostat. Users often confuse sensor failure with a compressor malfunction or freon leak. If the compressor does not turn on at all, and when you turn the control knob to the “maximum” position, there is no click, this is the first sign of a problem. It is also worth paying attention to the nature of the motor’s operation: if it hums continuously without turning off, and the temperature in the chamber drops below normal, freezing the food, this also indicates “sticking” of the contacts inside the thermostat.
For a more accurate diagnosis, you can conduct a simple test. Unplug the device, defrost it and find the thermostat terminals. Test the contacts with a multimeter: in normal conditions (at room temperature) the circuit should be closed. If the device shows a break, it means the part is faulty. Sometimes the contacts can burn out, creating high resistance, which also requires replacing the element.
⚠️ Attention: If after defrosting and turning on the refrigerator began to work normally, but after a few days the situation repeated itself, the problem may not be with the thermostat, but with a leak in the system or a clogged capillary tube. In this case, replacing the sensor will not help.
There is another indirect sign - the formation of a “snow coat” only on the rear wall or, conversely, the complete absence of frost when the compressor is running. In the model Biryusa 22 the thermostat controls shutdown cycles, and if it “lies” about the temperature inside the chamber, the modes are disrupted. Checking the integrity of the capillary tube visually is also important: there should be no traces of oil or mechanical damage.
Necessary tools and preparation
The success of the operation directly depends on the correct preparation of the workplace and the availability of the necessary tools. You don't need complex industrial equipment, but the set should be complete so as not to interrupt the process of searching for the missing screwdriver. The model Biryusa 22 is characterized by the use of standard screws and latches, so a basic DIY kit will be sufficient.
Be sure to make sure that you have a new thermostat on hand, completely identical to the old one. They may differ in the length of the capillary tube, thread diameter and contact location. If you buy a part at the market or in a store, it is better to take an old sample with you for comparison. The markings are usually applied to the body, but the visual similarity of the parameters is more important.
For work you will need:
- 🔧 A set of screwdrivers (phillips and flat) - for removing panels and terminals.
- 🔪 A sharp knife or blade - for carefully cutting off old insulation or seal.
- 🧤 Gloves - so as not to stain your hands with oil and leave marks on the plastic.
- 📸 Smartphone - take a photo of the wire connection diagram before disconnecting.
Before starting any work be sure to unplug the refrigerator from the power supply. This is a basic safety rule and, if ignored, may result in electric shock or short circuit. It is also recommended to defrost the chamber in advance so that water does not flow across the floor and does not get on the electrical contacts during dismantling.
☑️ Preparing to replace the thermostat
Access to thermostat in Biryusa 22
The design of refrigerators Biryusa with a top freezer requires the location of the thermostat inside the freezer or in a special compartment above it. In the model Biryusa 22 most often the sensor is installed in a plastic box, which is attached to the top panel of the freezer. To get to it, you need to remove the decorative trim or the lighting shade, if it is located nearby.
The process begins by opening the freezer door. Inspect the upper part of the interior. You will see a plastic panel covering the technical components. It can be attached with self-tapping screws or held on with plastic latches. If screws are visible, carefully remove them. If there are no screws, the panel needs to be pryed off with a flat screwdriver, but this should be done extremely carefully so as not to break the “ears” of the fasteners, which become very fragile on frosty plastic.
⚠️ Attention: Plastic in the freezer loses its elasticity over time. Before attempting to remove the panel, let the refrigerator stand turned off for at least 30-40 minutes so that the plastic temperature reaches room temperature. This will reduce the risk of breakage of the fasteners.
After removing the outer panel, the thermostat itself will be revealed to your view. This is a device with an adjustment knob extending outward and a capillary tube extending deep into the body. This tube is very thin and sensitive to creases. Capillary tube is the “nerve” of your refrigerator, transmitting information about the temperature. Damaging it means dooming the device to expensive repairs with refilling with freon.
Design features of Biryusa 22
In some modifications of Biryusa 22, the thermostat can be hidden under an additional layer of thermal insulation (foam or foam rubber). Do not forcefully pull out the sensor if you feel resistance. Carefully bend the insulation to make way for removing the tube.
Step-by-step instructions for dismantling
The most critical step is the physical removal of the old thermostat. The sequence of actions is important here. First you need to release the electrical part, and then carefully remove the sensitive tube from the internal volume of the chamber. Take your time, sudden movements can lead to a break in the tube inside the thermal insulation, which will require disassembling the entire housing.
Perform the steps in the following order:
- Take a photograph of the location of the wires suitable for the thermostat terminals. Even if you think you will remember the colors, a photograph will save you from assembly errors.
- Disconnect the wires from the contacts. To do this, you may need to remove the protective cap or simply pull out the terminals (chips) if they are detachable. If the wires are soldered, they need to be carefully unsoldered, marking each with a marker.
- Remove the temperature control knob. It is usually simply pulled onto the rod and removed by hand. Underneath there may be a locking screw or nut that secures the thermostat housing.
- Unscrew the fastening nut or screws holding the sensor housing in the mounting hole.
- Carefully pull the capillary tube out of the hole in the chamber wall. Movements should be smooth, without jerking. The tube may be glued or pressed, so help yourself by turning it slightly.
If the tube goes deep into the thermal insulation layer and does not give in, under no circumstances pull it by force. In some cases, it is necessary to partially remove the top cover of the refrigerator (metal casing) in order to gain access to the tube entry point from the inside. However, in Biryusa 22 usually it is enough to work carefully from inside the chamber, controlling the bending of the tube.
Installation of a new thermostat
Installation of the new element is carried out in the reverse order, but taking into account some nuances. The new thermostat may have a longer capillary tube than required. Under no circumstances should the excess be cut off! They need to be carefully rolled into a ring with a diameter of at least 3-4 cm and placed in a free space outside the freezer, but within the refrigerator body, so that they do not interfere with the operation of other components.
Insert the sensitive tube into the hole until it stops, repeating the trajectory of the old one. Make sure it is not twisted or pinched by sharp edges of plastic or metal. Secure the thermostat housing with the mounting nut or screws. Do not put on the adjustment knob yet - you will need it for the final adjustment.
Connect the electrical wires strictly according to the photograph taken earlier. If you used a label, check it. The contacts should fit tightly and not dangle. If the terminals are oxidized, sand them with fine-grit sandpaper before connecting. Contact reliability is critically important, since the compressor starting current passes through them.
The table below will help you navigate the typical contact designations, although wire colors may differ from manufacturer to manufacturer:
| Contact designation | Function | Typical wire color |
|---|---|---|
| 3 - 4 | Main circuit (compressor) | Red / Brown |
| 3 - 6 | Lamp / Fan | White / Blue |
| Grounding | Protective circuit | Yellow-green |
After connecting the wires, reinstall the plastic panel and decorative trims. Make sure that all latches click into place. Only after complete assembly can you put on the temperature control knob.
Checking and setting
The final stage is testing the work performed. Plug in the refrigerator. In the first minutes it should work normally. Listen to the sound of the compressor starting: it should be smooth, without humming or knocking. If the motor starts, this is already a good sign - the electrical circuit is assembled correctly.
Now you need to adjust the temperature. Set the regulator knob to the middle position (usually this is number 3 or 4 out of 5-7 possible). Let the refrigerator run for several hours. Check the temperature in the freezer and refrigerator compartments using an external thermometer. If the refrigerator “does not freeze” or freezes too much, adjustments will be required.
For precise adjustment, there is sometimes an adjusting screw under the seal on the thermostat rod. You should twist it very carefully, making half a turn, and wait for the operating mode to change. However, in most household cases, correct installation of the handle on the panel is sufficient. If after 5-6 hours of operation a uniform layer of frost appears on the back wall of the refrigerator compartment, and the compressor periodically turns off, then the replacement was successful.
⚠️ Attention: Complete stabilization of the temperature regime and entering the operating cycle may take up to 24 hours. Do not load the refrigerator with food in the first day after replacing the thermostat; let it gain temperature in empty mode.
What to do if the new thermostat clicks, but the compressor does not starts?
If you hear the relay click, but the motor is silent, the problem may not be in the thermostat, but in the compressor start relay or the motor itself. Also check whether the terminals on the thermostat contacts are tight. Perhaps contact is not achieved due to oxidation or weak clamping.
Is it possible to use a thermostat from another refrigerator model?
Technically - yes, if the mounting dimensions, thread length and temperature range match. However, the length of the capillary tube must be sufficient. If the tube is shorter, the sensor will not work correctly. If it is longer, it can be carefully wound into a ring, the main thing is not to bend it.
Why did the refrigerator start working longer after the replacement?
The new thermostat may have a slightly different temperature response range. Also, if you do not fully insert the capillary tube into the seat, the sensor will “think” that the chamber is warmer than it actually is and cause the compressor to work longer. Check the depth of the tube.
Is it necessary to evacuate the system when replacing the thermostat?
No, if you only change the electrical part and the capillary tube without violating the integrity of the freon circuit. Evacuation and refilling are only required if you accidentally puncture the tube and freon comes out. This does not happen with a standard replacement.
How often do you need to change the thermostat in Biryusa?
The service life of the thermostat is usually 5-10 years or more. It is not a consumable item and is replaced only after a breakdown. Preventative replacement is not required if the old device maintains the temperature properly.