If you notice that your refrigerator has stopped freezing, but the compressor is running almost without interruption, most likely occurred depressurization of the circuit. The refrigerant circulating inside the system could evaporate through a microscopic hole in the tubes. This is a common problem faced by owners of equipment of any brand, be it Indesit, Atlant or LG.
It can be difficult to independently detect where the gas is escaping, since freon is odorless and colorless. However, there are proven diagnostic methods that allow you to localize damage without complex equipment. It is important to understand that simple refueling will not solve the problem unless the source of the leak is eliminated.
In this article we will look at how to find a fistula in the system, what tools are needed for repairs and whether it is possible to do the work yourself. We will look at the nuances of working with different types of refrigerants and explain why it is sometimes cheaper to replace the evaporator than to try to seal it.
Main signs of loss of refrigerant
The first and most obvious symptom is lack of cold in the main chamber or freezer when the motor is running. The compressor hums for hours, trying to gain temperature, but the thermostat does not open the circuit. If at the same time the back wall inside the refrigerator remains warm or barely cool, the probability of a leak is more than 80%.
⚠️ Attention: If the compressor wears out without cooling, it may burn out. If symptoms are detected, immediately disconnect the device from the network until diagnostics are carried out.
The second sign is swelling of the evaporator or the appearance of oily spots under the unit. Since freon circulates in the system along with compressor oil, the release of gas is often accompanied by the release of lubricant. On the condenser tubes or near the evaporator you can notice characteristic dark streaks.
It is also worth paying attention to the operation of the system No Frost. If the fan is humming, but no cold air is flowing, and there is no frost on the evaporator (or it is uneven), this indicates a problem with refrigerant circulation. In older models, a sign may be the complete absence of frost on the back wall of the crying type.
Diagnostics: how to find the location of the leak
To accurately determine the location of the damage, technicians use specialized tools. A simple visual inspection is often not enough, since microcracks can be hidden under a layer of thermal insulation or factory paint. The most effective method is the use of a leak detector or a soap solution.
A soap solution is a budget method available to everyone. It is necessary to mix water with liquid soap or dishwashing detergent until a thick foam forms. This mixture is applied to all accessible tube connections, capacitor and solder joints. If there is pressure left in the system, bubbles will begin to inflate at the leak site.
A more professional approach involves the use of nitrogen and a pressure gauge station. The system is filled with inert gas under pressure and the hissing is listened to. To search for microscopic fistulas, electronic leak detectoris used, which reacts to the concentration of freon vapor in the air. Another popular method is using an ultraviolet additive in the oil, which glows under a UV lamp.
Necessary tools and materials
Repair of the refrigeration circuit requires specific equipment. Without a vacuum pump and a filling station, it will not be possible to do the job efficiently, since there should be no moisture or air left in the system. The presence of oxygen or water will lead to the formation of acid, which will destroy the compressor from the inside.
To solder copper tubes, you need a gas cylinder with a propane-oxygen or propane-butane mixture. An ordinary household soldering iron will not help here, since the melting temperature of solder requires an open flame. You will also need silver or phosphorus-copper solder and flux for high-quality sealing of the seam.
Below is a table of the main tools needed to fully restore the system:
| Tool | Purpose | Importance |
|---|---|---|
| Vacuum pump | Removing moisture and air from the circuit | Critical |
| Gauge station | Pressure control during evacuation and filling | Critical |
| Gas burner | Soldering copper tubes | Critical |
| Leak detector | Search for leaks | High |
| Set of pipe cutters | Cutting copper pipes without chips | Medium |
Separately, it is worth mentioning the freon cylinder. The type of refrigerant must strictly correspond to that for which your refrigerator is designed (R134a, R600a or R12). Using the wrong gas will result in incorrect operation or damage to the compressor. The marking is usually indicated on the nameplate on the back of the unit.
Technology for eliminating leaks and soldering
After detecting a fistula, it is necessary to decide on the method of restoration. If the damage is in a visible area of the copper tube, it can be soldered. To do this, the area is cleaned to a shine, heated with a burner and solder is added. It is important not to overheat the tube so as not to form burn on the reverse side.
☑️ Procedure for soldering
The situation becomes more complicated if the leak occurs in the foamed evaporator (inside the wall of the refrigerator). In this case, cutting out a piece of the wall and welding a new coil is a labor-intensive and messy process. Most often, experts suggest installing an external crying evaporator (aluminum plate) inside the chamber or mounting a condenser outside on the back wall.
⚠️ Attention: When working with freon R600a (isobutane), exercise extreme caution. This gas is explosive. All soldering work is carried out only after thoroughly purging the system with air.
After soldering, the system must be pressurized with nitrogen. The pressure is raised to 10-15 atmospheres and left for several hours. If the pressure gauges show a drop in pressure, it means that the seal has not been restored, and the search for a leak continues. Only after making sure that there are no losses can you move on to the next stage.
Evacuating and filling the system
An attempt to fill the refrigerator without preliminary evacuation is a gross mistake. There will certainly remain moisture in the system, which at low temperatures will freeze in the capillary tube, forming an ice plug. This will cause the refrigerator to stop freezing again after a few hours of operation.
The vacuuming process takes from 30 minutes to an hour. The vacuum pump is connected through the service pipe, and the pressure in the system is brought to minimum values. This allows all the moisture from the oil and the walls of the tubes to boil away. After this, close the valve and check whether the system holds a vacuum.
Why can’t you fill it “by eye”?
The amount of refrigerant must be strictly by weight (usually 60-140 grams). Overfilling will lead to increased pressure and stopping the compressor, and underfilling will lead to overheating and insufficient cold.
Refilling is carried out strictly according to the scales. The freon cylinder is placed on an electronic scale and the gas is turned on until the desired value indicated on the nameplate is reached. The pressure can be adjusted as the refrigerator operates, but the base charge must be accurate. For different models Bosch or Stinol the standards may differ.
The cost of repair or purchase of a new refrigerator
When deciding on repairs, it is important to assess the economic feasibility. If a compressor replacement and complex soldering of a foamed evaporator are required, the cost of work can be up to 70% of the price of a new device. In such cases, it is often more profitable to purchase new equipment with a warranty.
However, if the problem is solved by installing an external capacitor or simply soldering an accessible tube, the repair will extend the life of the unit by 5-7 years. This is especially true for expensive models with inverter compressorwhere replacing the motor is unreasonably expensive.
It is important to consider the age of the refrigerator. If it is more than 10-12 years old, other components (seals, thermostat, electronics) may also be worn out. Comprehensive diagnostics will help you make an informed decision.
Is it possible to fill a refrigerator with freon yourself without a vacuum sealer?
Theoretically, you can squeeze out the air freon, but in practice this leads to moisture entering the system. Moisture will cause corrosion and ice blockage. Without a vacuum pump, long-term repairs are impossible.
How much does it cost to refill with freon from a specialist?
The price consists of the cost of the visit, diagnostics, materials (freon, solder) and the complexity of the work. On average, leak detection and refilling cost from 3,000 to 6,000 rubles, depending on the region and model.
Is freon dangerous for humans?
Modern freons (R134a, R600a) are not toxic in small quantities, but displace oxygen. There may be a suffocation hazard in a confined area. R600a is also explosive at a concentration in air of more than 13%.