A decrease in the efficiency of brand refrigeration equipment Atlant often confuses the owner, especially when the unit hums but does not freeze. In most cases, the root of the problem lies in a violation of the circulation of refrigerant through the system, namely in the blockage of a narrow channel known as capillary tube. This part is responsible for creating a pressure differential and throttling the freon, turning it from gas into liquid before entering the evaporator.
An attempt to clean this element requires not only technical skills, but also an understanding of the physics of the processes occurring inside a sealed circuit. Unlike replacing filters or seals, working with a capillary implies a violation of the integrity of the system, which entails the need for subsequent evacuation and gas filling. Ignoring these steps will lead to the fact that the equipment will not work, even if the mechanical blockage is eliminated.
Before taking active steps, you need to make sure that the diagnosis is correct. The absence of cold does not always indicate a clogged capillary; sometimes leaks, compressor failure, or electronic problems are to blame. However, if you hear a characteristic gurgling sound that suddenly stops, or notice that the condenser is only partially heated, the likelihood of a blockage in a tube with a diameter of less than a millimeter becomes the main one.
Diagnostics of a blockage and signs of malfunction
The first step in the process of restoring the unit's performance is an accurate diagnosis. Capillary tube in refrigerators Atlant has a very small flow area, so even microscopic particles of copper oxides, paraffin or ice can completely block the refrigerant flow. The symptoms are often similar to other breakdowns, so it is important to pay attention to the details of the behavior of the motor-compressor.
Pay attention to the temperature of the condenser grid at the back of the device. In good condition, it should heat up evenly over the entire area. If you observe heating only in the upper part or directly at the outlet of the compressor, and then the grate remains cold, this is a sure sign that freon is not circulating. The pressure in the discharge system increases, and a deep vacuum is created at the suction, which is why the motor can work with overload or turn off by a thermal relay.
⚠️ Attention: If the compressor operates continuously, but there is no cold, and at the same time you can hear periodic quiet gurgling or hissing, under no circumstances continue to operate in this mode for a long time. This can lead to burning of the motor windings due to the lack of cooling and lubrication, which are normally provided by circulating oil and freon.
To confirm the diagnosis, technicians often use the method of feeling the filter drier. If after several hours of operation this element becomes covered with frost or, conversely, remains at room temperature with a hot compressor, it means that the permeability of the system is impaired. It is also worth checking the evaporator: if it is completely dry and not covered with an even layer of frost (in models with a drip system), and the sound of flowing gas is heard inside, but there is no cold, the system is clogged.
Necessary tools and workplace preparation
High-quality cleaning capillary tube impossible without specialized equipment. You'll need more than just a set of wrenches, but also tools for working with high-pressure copper piping. The main element will be a nitrogen cylinder with a reducer, which allows you to create controlled pressure for purging the system. An ordinary automobile compressor will not work here, since it will not be able to develop the necessary force to knock out a dense plug.
In addition to the pressure source, it is necessary to prepare a burner (gas or oxygen-acetylene), solder for copper pipes and flux. Since the refrigerator system Atlant is sealed, after cleaning you will have to resolder the connections. A vacuum pump will also be an indispensable tool, without which it is absolutely impossible to refill the system with new refrigerant - residual moisture and air will instantly damage the unit.
Do not forget about personal protective equipment. Working with open flames and chemicals requires caution. Be sure to use safety glasses and gloves. Prepare a container to collect residual oil and possible freon release. It is better to carry out all work in a well-ventilated area, since heating of old insulating materials or possible combustion of oil may release harmful substances.
Countercurrent nitrogen blowing technology
The most effective and common method of restoring patency is nitrogen blowing. The essence of the method is to create high pressure in a closed circuit, which pushes out foreign particles. It is important to understand that simply supplying gas is not enough - you need to create the correct vector of movement so as not to drive dirt even deeper into the bends of the evaporator, sealed into the refrigerator body.
The process begins by disconnecting the unit from the power supply and accessing the technical compartment. It is necessary to carefully unsolder the capillary tube from the filter drier and from the compressor. After this, the filter-drier must be replaced, since its sorbent is already saturated with moisture and contaminated, and reuse is impossible. In place of the removed filter, an adapter is installed to connect a hose with nitrogen.
The gas supply should be carried out in the direction opposite to the normal refrigerant flow (countercurrent). The pressure should be increased gradually, monitoring the pressure gauge readings. A sudden surge can damage the thin walls of the tubes or the evaporator. Usually a pressure of 10-15 atmospheres is enough to knock out the oil-paraffin plug. If the blockage is caused by copper oxides, the process may require several cycles of increasing and releasing pressure.
☑️ Purge algorithm
In some cases, when simple purging does not produce results, the “annealing” method is used. The capillary tube at the site of the suspected blockage (often this is the entrance to the evaporator or the outlet from the filter) is carefully heated with a burner until it turns dark cherry in color, while simultaneously supplying nitrogen. Thermal expansion of the copper and liquefaction of wax deposits helps clear the passage. However, it is important here not to overheat the tube, so as not to disturb its geometry and not burn it out.
Eliminating an ice plug in the system
The situation when the reason for stopping circulation is not solid debris, but water, deserves special attention. Moisture getting into the refrigerator circuit Atlant is a critical malfunction. When passing through a capillary tube, where the temperature drops sharply, the water freezes, forming an ice plug. A characteristic feature of such a breakdown is cyclical operation: the refrigerator freezes for some time, then stops, then starts working again after the ice has defrosted.
Dealing with an ice plug by blowing is pointless if the cause of moisture ingress has not been eliminated. The ice may melt when heated, but the water will not go anywhere and will freeze again in a narrow place. The only reliable way is to completely evacuate the system for a long time (at least 2-3 hours) with a powerful pump. Evacuation allows water to evaporate at low pressure and remove it from the circuit along with air.
⚠️ Attention: If, after evacuation and refilling, the problem with periodic freezing returns after a few months, it means that a source of moisture remains in the system. This may be poor-quality oil in the compressor or residual water in the motor windings, which gradually evaporate and freeze again.
To speed up the process of removing moisture, craftsmen sometimes use the method of blowing with warm nitrogen. The gas is heated by passing a hose through a container of hot water or using a special heater and fed into the system. Warm gas absorbs moisture better and carries it outside. After such a procedure, a new filter-drier with an increased content of zeolite must be installed, which will absorb residual moisture during operation.
Replacing the filter-drier and assembling the circuit
Filter drier in refrigerators Atlant plays the role of a barrier that retains mechanical particles and moisture. Whenever the circuit is opened, including cleaning the capillary, this element must be replaced. The old filter will no longer be able to effectively perform its functions, and the risk of re-clogging or acid formation in the system will increase many times over. Select an analogue strictly according to the catalog number or technical characteristics.
The process of soldering a new filter requires speed and accuracy. Copper has high thermal conductivity, so heat dissipates quickly. It is necessary to quickly warm up the joint and apply solder. It is important not to allow solder to get inside the tube, as this will create a new restriction and cause a blockage. Before soldering, make sure that the ends of the tubes are clean and degreased.
After installing all the elements, the system is pressurized with nitrogen to check the tightness. The pressure is raised to 15-20 atmospheres and the system is left under the control of a pressure gauge for several hours. If the arrow does not move, it means that the connections are sealed and you can proceed to vacuuming. Skipping this step risks that all the work on cleaning the capillary tube will go down the drain due to freon leakage through a microcrack.
| Stage of work | Pressure (atm) | Exposure time | Note |
| :--- | :---: | :---: | :--- |
| Nitrogen pressure testing | 15-20 | 2-4 hours | Checking for leaks |
| Vacuuming | 0.01 (residual) | 2-3 hours | Removing moisture and air |
| Refilling with freon | 0.8-1.2 (R600a) | By scale | Refrigerant mass control |
| Checking work | Working | 30 min | Control of currents and temperatures |
Which solder is best to use?
For soldering copper tubes of refrigerators, it is best to use silver solder with a silver content of 15% to 45%. It has better fluidity and strength compared to tin-lead analogues, and is also less susceptible to vibration loads, which is critical for the operation of the compressor.
Evacuation and refrigerant charging
The final and most critical stage in restoring the functionality of the refrigerator is evacuation and charging. After cleaning capillary tube air and moisture vapor remain in the system. The vacuum pump creates a vacuum, lowering the boiling point of water, due to which it evaporates even at room temperature and is removed from the circuit.
Refrigerant charging must be done strictly according to the weight indicated on the unit nameplate Atlant. The use of the eye method or pressure is unacceptable here, especially for modern refrigerants such as R600a (isobutane), which are explosive and require precise dosage. A lack of freon will lead to poor cooling, and an excess will lead to an increase in pressure and possible failure of the compressor.
After refueling, it is necessary to start the compressor and check its operation. The current consumption must correspond to the passport data. Uniform frost should appear on the evaporator, and at the outlet of the compressor the tube should be warm, but not hot. The capillary tube after entering the evaporator should begin to cool, which indicates the beginning of throttling and normal circulation.
⚠️ Attention: The R600a refrigerant used in many modern models is heavier than air and has no odor. When working with it, the use of open flame in the immediate vicinity of the refueling site is strictly prohibited in order to avoid an explosion of the gas mixture.
Frequently asked questions (FAQ)
Is it possible to clean a capillary tube without a nitrogen cylinder?
Theoretically, some craftsmen use compressors from old refrigerators to create pressure, but their power (usually up to 6-8 atm) is often not enough to break through a serious blockage in a narrow channel. In addition, such a compressor can drive moisture from its oil into the system. Using a nitrogen cylinder with a reducer is the only professional and reliable way.
Why does the refrigerator freeze after cleaning, but then stops again?
This is a classic sign of a “floating” clog or incomplete removal of moisture. Perhaps there is a piece of oxide left in the system that walks along the circuit and periodically blocks the capillary. Or the filter drier cannot cope with the volume of moisture, and an ice plug forms. Repeated evacuation and replacement of the filter are required.
Is it necessary to flush the system after cleaning the capillary?
Rinsing with special solvents (for example, R141b) is only required if the system has had oil combustion (acidic environment) or a large amount of dirt has entered the system. If the clog was a standard paraffin or oxide clog, a thorough nitrogen purge and filter replacement is usually sufficient. Washing is an additional operation that requires complete disassembly of the circuit.
What is the service life of the capillary tube in Atlant refrigerators?
The copper capillary itself does not have a limited service life and can work for decades. However, operating conditions, quality of installation and purity of the refrigerant affect its throughput. Blockages most often occur due to a leak in the system in the past or the use of low-quality refrigerant during previous repairs.