The situation when the refrigerator compressor Indesit works without stopping, and the temperature in the chambers is warm, is familiar to many equipment owners. Often this hides a serious problem with the refrigerant, namely a blockage in a narrow section of the line, known as capillary tube. This is a thin copper channel, the diameter of which is only about 0.6-0.9 mm, and even a microscopic particle of oxide or moisture can completely stop the circulation of freon.
Unlike simple breakdowns, such as replacing a lamp or adjusting the legs, cleaning the capillary requires specific skills and equipment. You will have to deal with a sealed system, high pressure and chemically active substances. Unprofessional intervention can lead to the final failure of the unit, so before starting work you should soberly assess your strengths and the availability of the necessary tools.
In this article we will analyze in detail the physical nature of blockages, methods for diagnosing them and step-by-step algorithm of actions to restore system patency. You will find out why in modern models Indesit with a door perimeter heating circuit specific problems arise and how to solve them correctly.
Diagnostics of capillary tube blockage
Before you start disassembling the unit, you need to make sure that the problem lies in the capillary. A characteristic sign is a running compressor that heats up to high temperatures, but at the same time evaporator in the freezer remains warm or is only partially cooled. If you touch the condenser (the grille at the back), you will notice that it is warm only at the beginning, and then cools down.
There are two main types of blockage: ice blockage and oil-mechanical blockage. An ice plug is formed due to moisture entering the system, which freezes at the narrowest point of the capillary. Oil blockage occurs due to thickening of the compressor oil or the ingress of decomposition products of the insulation of the motor windings. Diagnostics often carried out by eliminating other faults.
⚠️ Attention: If after defrosting the refrigerator for 24 hours without connecting to the network, the problem returns, then There is moisture or a mechanical barrier in the system that requires physical intervention.
To accurately determine the location (clogging), technicians use a thermal imager or simply feel the line. A sharp temperature change in the section of the tube before entering the evaporator or immediately after it indicates the location of the problem. In models Indesit with a foamed condenser, diagnostics becomes more complicated, since part of the line is hidden in the housing.
The necessary tools and preparation of the workplace
High-quality cleaning of the system is impossible without specialized equipment. You will need a vacuum pump to remove moisture and air, as well as a cylinder with dry nitrogen for purging. Nitrogen pressure must be regulated by a reducer, since excess pressure can rupture the thin-walled elements of the evaporator.
A kit for soldering copper pipes is also required: a torch (gas or oxygen-acoustic), solder with a melting point above 600 degrees and flux. The use of tin-lead solders for refrigeration equipment is unacceptable, since they cannot withstand vibrations and thermal expansion. To flush the system, you will need a solvent, for example R141b or purified Galosh gasoline.
- 🛠️ Gauge station —to control the pressure during evacuation and refueling.
- 🔥 Burner and consumables —to seal connections after work.
- 🧪 Washing liquid —for dissolving oil deposits inside the tubes.
- 🧹 Filter drier —a mandatory replacement element for any opening of the circuit.
Preparation of the workplace also plays a key role. Ensure good ventilation as refrigerant and solvent vapors may be toxic. Prepare a container in advance to drain old oil from the compressor if you plan to replace or flush it.
Nitrogen blowing technology in the opposite direction
The most effective method of dealing with mechanical blockages is nitrogen blowing in the opposite direction. To do this, you need to gain access to the capillary tube, which is usually soldered into the filter drier. After unsoldering the filter, nitrogen is supplied directly to the capillary from the condenser or evaporator side, depending on where access is easier.
It is important to understand that simply “blowing” nitrogen is not enough. It is necessary to create pulse pressure. A sudden opening of the nitrogen valve creates a hydraulic shock that can dislodge the stuck particle. If the blockage is icy, then blowing with warm nitrogen will help evaporate the moisture, but only subsequent deep vacuuming can guarantee success.
Why can’t you blow it with your mouth or a compressor?
Air from the lungs or a conventional compressor contains moisture and oil. The entry of even a microscopic amount of water into the system will lead to the formation of acid when mixed with freon, which will destroy the compressor from the inside in a few months.
In some cases, when the blockage is deep in the foamed part, craftsmen use the “pressure testing” method. The system is filled with nitrogen under pressure up to 15-20 atmospheres and left for a day. A drop in pressure will indicate a leak, and a stable pressure after purging will confirm the elimination.
☑️ Preparation for purging the system
Rinsing the system and replacing the filter-drier
If purge did not produce results, or if the compressor burned out and carried combustion products throughout the system, a complete flushing The flushing liquid is forced into the circuit under pressure or by gravity, and then blown out with nitrogen. This procedure is repeated until the exiting solvent becomes clear.
Replacement is a critical step. filter-drier. This element contains zeolite, which absorbs moisture. When the system is opened, the zeolite is instantly saturated with atmospheric power and loses its properties. Installing an old filter or storing a new one without plugs is unacceptable.
| Type of blockage | Symptom | Elimination method | Probability success |
|---|---|---|---|
| Ice plug | Periodic appearance and disappearance of cold | Evacuation and filter replacement | High |
| Oil clot | Constant absence of cold, quiet operation | Rinsing with solvent | Medium |
| Oxide film | Complete blockage after repair | Mechanical cleaning or replacement | Low |
| Combustion products | Black deposits on cut pipes | Multiple flushing of the circuit | Depends on the degree |
When installing a new filter, it is important to follow the flow direction indicated by the arrow on the housing. Soldering must be done quickly so as not to overheat the filter filler. After soldering all connections, the system is checked for leaks.
Refrigerant charging and evacuation
After successful cleaning and assembly of the circuit, the evacuation stage begins. This is the process of removing air and water vapor from the system. The vacuum pump should run for at least 30-40 minutes. The residual pressure should be no more than 5-10 microns (according to a deep vacuum gauge) or correspond to the arrow on the pressure gauge in the blue zone.
Refilling freon (R134a or R600a) is carried out strictly according to the weight indicated on the refrigerator nameplate Indesit. The use of cylinders without scales is unacceptable, since an excess of refrigerant will lead to high pressure and the compressor stops, and a lack of refrigerant will lead to insufficient cooling. R600a (isobutane) requires special care due to its explosive hazard.
⚠️ Attention: Isobutane (R600a) is heavier than air and odorless (in its pure form). When there is a leak, it accumulates in the lower part of the room. Work with this gas only in the absence of open flames and sparks.
After refueling, it is necessary to start the compressor and check the operation of the system. The motor current must correspond to the nominal value, and the temperature in different parts of the circuit must be distributed evenly. The capillary tube at the entrance to the evaporator should be covered with frost, which should not rise higher to the compressor.
Common mistakes during self-repair
One of the most common mistakes is trying to clean the capillary by simply biting it off with wire cutters and blowing with your mouth. This is not only ineffective, but also dangerous to health. Another mistake is neglecting to replace the filter drier. Many people believe that if it is “blown out,” it will work, but this misconception leads to re-clogging after a week.
Also, beginners often overheat the soldering joints, burning through the thin wall of the capillary or the evaporator itself. In models Indesit with aluminum evaporators, the use of conventional solder for copper without special fluxes for aluminum will lead to leaks. It is necessary to use special adapter bushings or solders.
- ❌ The use of oxygen instead of nitrogen for purging - this is a guaranteed oil explosion in the compressor.
- ❌ Lack scales when refueling leads to incorrect operation of the system.
- ❌ Warming the capillary with an open fire - can change its internal diameter or melt the solder.
Remember that a modern refrigerator is a complex thermodynamic machine. Repair mistakes can cost more than calling a repairman with a guarantee. If you are not confident in your abilities at the soldering stage or working with a vacuum, it is better to stop.
Questions and answers (FAQ)
Is it possible to clean the capillary without nitrogen and a vacuum pump?
Theoretically, you can try to push through the blockage with a syringe with a solvent, but this is a "treatment" blindly." Without evacuation, moisture will remain in the system, which after a short time will again create an ice plug or acid. The quality of such repairs will be extremely low.
How much does it cost to replace a capillary tube in a service?
The cost consists of the work of the technician, the cost of materials (freon, filter, tube) and the difficulty of access. On average, repairing the circulation system costs 40-60% of the cost of a new budget refrigerator.
Why does the refrigerator freeze after repair, but is very noisy?
The noise may indicate that there is air left in the system (poor vacuuming) or the compressor is out of balance. It is also possible that the capillary is of the wrong length or diameter, which creates excess pressure.
How to determine that the capillary is clogged and not a freon leak?
If there is a leak, the compressor works intermittently or constantly, but the condenser (grid at the back) is cold or slightly warm along its entire length. When the capillary is clogged, the condenser is often hot in the first half and cold in the second, and the pressure in the system is normal or increased.