The situation when the refrigerator stops freezingand the compressor continues to hum often confuses the owner. In most cases, the cause is a leak refrigerant from the circuit, which requires immediate attention. Many people wonder whether it is possible to solve the problem on their own or is it better to call a specialist.
The process refilling the refrigerator with freon is technically complex and requires specific equipment that is rarely found in everyday life. In addition, working with gas under pressure carries certain risks for the health and safety of the unit itself. However, understanding the principles of operation of the system will help diagnose the malfunction and assess the scale of the necessary work.
In this article we will analyze in detail all the stages of restoring the functionality of the refrigeration unit, from finding a leak to the final start-up. You will learn about the types of gases used, the features of evacuation of the system and nuances that are often overlooked. Without eliminating the leak, any freon charge will only give a short-term effect, after which the gas will evaporate again.
Diagnostics and search for refrigerant leaks
Before proceeding with active ones actions, you need to make sure that the problem lies precisely in the absence of freon. If the compressor runs continuously, but there is no cold, and there is no uniform frost on the evaporator, this is the first sign of depressurization. Visually, you can notice oily stains on the tubes or in the soldering areas, since the oil often comes out along with the gas.
To accurately determine the location of the leak, technicians use electronic leak detector or a soap solution. At home, you can try applying a thick soap solution to suspicious areas of pipes and connections. The appearance of bubbles will indicate the release of gas. Particular attention should be paid to the foamed parts of the body, where the tubes can be damaged by corrosion.
Sometimes a leak occurs in the evaporator, which is located inside the freezer. If you notice swelling in the back wall or rust, that's most likely where the damage is. In such cases, simple refilling is not enough - you will need to replace the evaporator or install an external circuit.
⚠️ Attention: If you smell a strong gas odor or see a strong hissing sound, ventilate the room immediately. Although modern freons are not toxic in small doses, they displace oxygen and at high concentrations can cause suffocation.
After identifying and repairing a hole in the system (usually by soldering), it is necessary to perform a nitrogen pressure test. This is a critical step to ensure that all pressure joints are sealed. Only after making sure that the system maintains pressure for several hours can you move on to the next stage.
Necessary equipment and tools
Quality refueling the refrigerator is impossible without a professional set of tools. Attempts to use automotive kits or homemade methods often lead to damage to the compressor or ineffective operation of the refrigerator. The master's basic kit includes several key components.
First of all, you need gauge scales (manifold), which allow you to control the pressure in the system and the amount of gas being charged. A vacuum pump is also required to remove moisture and air from the circuit. The presence of scales for accurate weighing of a cylinder with freon is critically important, since refilling is carried out strictly in grams.
- 🔧 Gauge station with hoses (blue, red, yellow).
- 💨 High-quality vacuum pump performance.
- ⚖️ Electronic scales with an accuracy of 1 gram.
- 🔥 Gas torch and solder for soldering copper tubes.
- 🔪 Pipe cutter and rolling machine for preparing connections.
Stands separately mention the cylinder with inert gas (nitrogen). It is used not only for crimping, but also for purging the system during soldering, which prevents the formation of oxides inside the tubes. Oxides can clog the capillary tube, which will lead to expensive repairs.
Selecting the type of freon and preparing the system
Modern refrigerators operate on different types of refrigerants, and using the wrong gas can damage the equipment. The most common are R134a (tetrafluoroethane) and R600a (isobutane). The first is used in most old and medium-sized models, the second - in modern, more environmentally friendly units.
Freon R600a is explosive, which requires special care when working. Its quantity in the system is very small (often less than 100 grams), so weighing accuracy plays a decisive role here. Freon R134a is more inert, but requires careful evacuation, as it is sensitive to moisture.
Preparation of the system begins with the complete removal of residual old gas and oil. If there was a compressor breakdown in the system, an acid deposit could form, which must be neutralized by flushing. After this, the circuit is filled with nitrogen to check for leaks.
What is the difference between R134a and R600a freons?
R134a freon operates at a higher pressure and requires the use of mineral or semi-synthetic oils. R600a (isobutane) is a hydrocarbon that operates at low pressure, requires less gas, but is flammable. It is strictly forbidden to mix them, as this will lead to a change in the characteristics of the oil and failure of the compressor.
For R134a, polyester oils (POE) are often used, which are hygroscopic and quickly absorb moisture from the air. Therefore, the time when the system is open should be minimal.
The process of evacuation of the refrigeration circuit
Evacuation is a stage that is most often ignored by amateurs, and it is this that causes repeated breakdowns. There should be nothing left in the system except pure freon. Air and, most importantly, moisture must be completely removed.
The process is as follows: the yellow hose of the pressure gauge station is connected to the service fitting, the second end of which is connected to the vacuum pump. The valve opens and the pump begins to pump out air. The pressure in the system should drop to a deep vacuum (usually below 500 microns).
The duration of the procedure depends on the power of the pump and the volume of the system, but usually ranges from 30 minutes to 1 hour. To speed up the process and better remove moisture, you can slightly warm up the compressor with a hairdryer (carefully, without overheating the windings) or periodically turn it on for a few seconds, if the design allows it.
| Parameter | R134a | R600a | Unit of measurement |
|---|---|---|---|
| Boiling pressure | -26.1 | -11.7 | °C at 1 atm |
| Freezing point | -101 | -159 | °C |
| Vapor density | 4.25 | 2.05 | kg/m³ |
| Ozone depletion potential | 0 | 0 | ODP |
After pumping is completed, the valve is closed and the pump is turned off. You need to wait 15-20 minutes and check the pressure gauge readings. If the arrow remains in place, it means the system is sealed and ready for refilling. If the pressure begins to increase, it means that a microcrack remains somewhere.
☑️ Check before refueling
Refrigerant charging technology
The process itself filling the refrigerator with freon carried out strictly by weight. The label, usually located on the back wall or inside the chamber, indicates the type of refrigerant and its exact amount in grams. A deviation of even 10-15 grams can significantly affect performance.
The cylinder with freon is installed on the scales. The hose from the cylinder is first opened slightly to expel air from the hose itself, then quickly connected to the service fitting of the refrigerator. The valve at the station opens and gas begins to flow into the system.
Refilling with the liquid phase (by turning the cylinder upside down) is allowed only for some types of oils and systems, but for household refrigerators with a capillary, they are more often refilled in the vapor phase through the top of the cylinder, controlling the weight. If you need to fill the exact amount, the cylinder is weighed before and after, or the weight decrease is monitored in real time.
⚠️ Attention: Never fill the refrigerator “by eye” or until the circuit is completely filled with liquid. Liquid shock can instantly destroy compressor valves. Always rely on the weight specified by the manufacturer.
After filling the main volume, allow the refrigerator to stand for a few minutes to equalize the pressure. Then a test launch is performed. At this moment, it is important to monitor the current consumption of the compressor and the temperature of the condenser (grid at the back).
Control start-up and operation setup
The final stage is a performance check. After turning on the compressor, after 5-10 minutes the condenser (rear grill) should begin to warm up evenly. First, the area near the compressor warms up, then the heat spreads along the entire length.
Frost should begin to appear in the freezer compartment. In systems No Frost you will not be able to immediately see frost on the products, but the walls of the evaporator should become cold to the touch. If one part of the grille is hot and the other is cold, this is a sign of a clogged capillary tube or an incorrect amount of freon.
The compressor motor current must correspond to the rating specified in the documentation. An excess of current indicates an overload (possibly too much freon or problems with ventilation), and a low current indicates an underload of the system.
If all parameters are normal, the service fitting is sealed. The soldering area must be checked with a leak detector or soap solution. After the soldering has cooled, you can install decorative casings and return the refrigerator to its place.
Is it possible to fill a refrigerator with freon from a canister? lighters?
Absolutely not. The lighter gas contains impurities and oils that are not compatible with refrigeration oil. This will lead to the formation of acids, blockage of the capillary and combustion of the compressor. Use only clean refrigeration freon of the appropriate brand.
How much does it cost to refill a refrigerator with freon at the service?
The price depends on the model and type of freon. On average, a craftsman’s work with materials costs from 2,000 to 5,000 rubles. Independent purchase of equipment (pump, station, scales) will cost much more, so one-time refilling with your own hands is not economically feasible.
How often do you need to change freon in a refrigerator?
In a working, sealed refrigerator, freon does not change and never runs out. It circulates in a closed loop for decades. If the gas disappears, it means that a hole has formed that needs to be found and sealed.
Is it dangerous to breathe freon vapors?
Freons R134a and R600a are not toxic in small quantities, but they are heavier than air and displace oxygen. In a confined space, high concentrations may cause suffocation. In addition, when heated above 250°C, freon decomposes to form phosgene, a poisonous gas.