Faced with the fact that the freezer has stopped freezing and the compressor is working non-stop, many owners of household appliances immediately think about a lack of refrigerant. Indeed, freon leak is one of the most common reasons for the failure of refrigerators. However, the process of restoring the functionality of the cooling system is far from being as simple as it might seem at first glance, and requires not only special equipment, but also a deep understanding of thermodynamics.
Before taking active steps, you need to clearly understand that refrigerant (as freon is often called in a professional environment) is not easy gas, but a working fluid circulating in a closed circuit under pressure. Replenishing the amount of refrigerant without eliminating the cause of the leak will only lead to a temporary effect and subsequent failure of the compressor building. In this article we will analyze all the stages of diagnostics, troubleshooting and technologically correct refilling.
It is also worth noting that modern models of refrigerators, be it Indesit, Atlant or Samsung, use different types of refrigerants, each of which has its own characteristics. Incorrect selection of substances or violation of vacuum technology can nullify all efforts. Therefore, carefully study the theoretical part before picking up the tools.
Diagnostics: is freon really needed?
Symptoms of a lack of refrigerant are often confused with a broken thermostat or a clogged capillary tube. If you notice that the compressor is constantly humming, but there is no cold in the chambers, or the freezer is covered with a “fur coat” only on one side, these are alarming signals. It is important to conduct an initial visual check of of the evaporator and the condenser grid.
Pay attention to the temperature of the tubes leaving the compressor. In a normally operating unit, one tube should be hot and the other should be warm or room temperature. If both tubes are cold or, conversely, both are hot, this may indicate problems with gas circulation. It is also worth checking for oily stains on the floor under the refrigerator or in the area of the engine compartment.
⚠️ Attention: Oil stains under the refrigerator are almost 100% a sign of depressurization of the system, since freon circulates along with the compressor oil.
For more accurate diagnostics, professionals use electronic leak detectors that react to the slightest concentration of gas in the air. However, at home, you can limit yourself to a soap solution, applying it to suspicious joints and connections. The appearance of bubbles will indicate where the gas is escaping.
Necessary tools and materials
High-quality refilling of the refrigerator is impossible without specialized equipment. An attempt to solve the problem using “folk methods” or using cans for household air conditioners often leads to damage to an expensive compressor. You will need to collect a whole arsenal of tools for working with copper tubes gas media.
First of all, you need vacuum pumpwhich allows you to remove air and moisture from the system. The remaining moisture, when frozen, will turn into an ice plug, completely blocking the circulation of the refrigerant. A manometric manifold is also required to monitor the pressure in the system during various stages of work.
- 🛠️ Set for soldering copper pipes (torch, solder, flux) - necessary for sealing the system.
- 📏 High-precision electronic scales - for weighing the amount of gas being charged.
- 🧪 A cylinder with the appropriate type of freon (R134a, R600a or R12).
- 🔧 Leak detector or soap solution to check the tightness.
Special attention should be paid to the choice of solder. For refrigeration systems operating under high pressure, refractory solders containing silver are usually used. Soft tin solder may not withstand vibrations and temperature changes, which will lead to repeated leakage.
Finding and eliminating leaks
The most difficult stage of repair is finding the place where the gas leaves the circuit. Most often, leaks occur in solder areas, on the evaporator (especially if it is placed inside a plastic box) or in the foamed part of the case. If a leak is found on a visible part of the pipeline, repair is relatively simple: the place is cleaned and sealed.
The situation becomes more complicated if there is damage built-in evaporator, which is located inside the wall of the refrigerator. In this case, it is often necessary to either open the wall, which violates the thermal insulation, or turn off this circuit and install an external plate evaporator. The latter option is less aesthetically pleasing, but more reliable and repairable in the future.
Can sealant be used to find leaks?
The use of liquid sealants (“stoppers”) at home is highly not recommended. They can clog the capillary tube and filter drier, which will lead to the need to completely replace the compressor and costly flushing of the system.
After eliminating visible defects, it is necessary to pressurize the system with nitrogen. This allows you to create excess pressure and ensure that all connections are tight before vacuuming. The pressure during testing must correspond to the operating parameters of a particular refrigerant.
System vacuum technology
Evacuation is a critically important process that many beginners underestimate. Its purpose is not just to pump out air, but to remove moisture, which is always present in the atmosphere and inside the components of the refrigerator. At low pressure, water boils at room temperature and evaporates, leaving along with the air.
The process is as follows: a pressure gauge station and a vacuum pump are connected to the service fitting. The pump turns on and the system is evacuated until a deep vacuum is achieved. The operating time of the pump depends on the volume of the system and the degree of its contamination with moisture, but is usually at least 30 minutes.
It is important to monitor the pressure gauge readings. The needle should drop into the blue zone (vacuum) and remain stable there. If, after turning off the pump, the pressure begins to increase, it means that there is a leak in the system or moisture is actively evaporating from hard-to-reach places.
☑️ Evacuation checklist
⚠️ Attention: Never turn on the refrigerator compressor if the system a vacuum has not been created or it is filled with air. This is guaranteed to lead to a wedge of the motor or combustion of the winding.
The process of filling the refrigerant
Filling the refrigerator with freon is carried out strictly by weight. The nameplate, usually located on the back wall or inside the chamber, indicates the type of refrigerant and its exact amount in grams. Using a cylinder with scales is the only correct way to fill the system.
First, the freon cylinder is connected to the manometric manifold. After opening the valve, you need to release a little gas to displace the air from the hose. Then, by opening the valve on the manifold, we start the gas supply to the system. Since the pressure in the cylinder is higher than in an evacuated refrigerator, gas will begin to flow on its own.
At the initial stage, refueling can be done with the compressor turned off. When the pressure in the system is equal to the pressure in the cylinder, you need to start the refrigerator engine. Further refilling is carried out in small portions through the suction pipe while the engine is running.
| Refrigerant type | Working pressure (bar) | Features | Flammability |
|---|---|---|---|
| R134a | 1.0 - 1.5 | Standard for modern models | Non-flammable |
| R600a (Isobutane) | 0.5 - 0.8 | Eco-friendly, requires caution | Explosive |
| R12 | 1.2 - 1.8 | Used in old equipment | Non-flammable |
| R404A | 2.0 - 2.5 | For industrial and No Frost | Non-flammable |
During the refueling process, it is necessary to control the compressor current consumption using current clamps. It must not exceed the nominal values specified in the documentation. It is also important to monitor the freezing of the evaporator: it should be covered with frost evenly, starting from the freon inlet.
Sealing the service pipe and final sealing check
After the required amount of refrigerant has been reached and the refrigerator has entered operating mode, it is necessary to hermetically close the system. For this, the “pinching” method is used. While the compressor is running, the service tube is clamped, sealed, and only then disconnected from the hose.
This operation requires skill: if you disconnect the hose before soldering, air and moisture will enter the system, and the entire procedure will have to be repeated. The soldering area should be neat, without solder deposits that could block the passage hole of the tube.
The final stage is to check the operation of the unit for several hours. You need to make sure that the refrigerator reaches temperature, turns off when the set parameters are reached, and that the compressor cycles are normal. The absence of extraneous noise and vibrations is also checked.
How much freon is needed to refill a regular refrigerator?
The amount of freon varies depending on model and volume of chambers. Typically, household refrigerators use between 30 and 150 grams of refrigerant. The exact figure is always indicated on the manufacturer's technical sticker.
Is it possible to fill a refrigerator with freon from a car air conditioner?
It is absolutely not possible. Cars and refrigerators use different types of freons and, more importantly, different oils. Mixing oils will lead to the formation of an emulsion, which will clog the capillary system and disable the equipment.
Why does the refrigerator freeze worse after refueling?
There may be several reasons: under-filling or over-filling of the system, the presence of an air lock, a malfunction of the filter-drier or incomplete evacuation. It is also possible that the problem was not only in the leak, but also in the compressor.