Loss of cold working in the refrigerator is always stressful, because food supplies are at risk. Often the cause of a malfunction is a leak refrigerant, which circulates through the system, taking away heat. Owners of the units immediately begin to look for information on how to fill the refrigerator with freon themselves in order to save on calling a technician.
However, the process of restoring the functionality of the equipment requires not only theoretical knowledge, but also specialized equipment. Simply “topping up” gas, as in a car air conditioner, will not work here due to the design features of the circuit. You will need to completely remove the remnants of the old substance, create a vacuum and fill the system strictly by weight.
In this article we will analyze all the stages of the complex procedure, the types of gases used and safety measures. You will understand where simple DIY repairs end and work that requires a license and expensive tools begins.
Signs of a leak and types of refrigerants
Before taking active steps, you need to make sure that the problem lies precisely in the lack of gas. The compressor can operate continuously, hum, but not create cold if a microcrack has formed in the system. A characteristic sign is the heating of the compressor housing in the absence of cold in the evaporator.
Modern refrigerators are charged with different types of working substances. The most common for many years was R-134a, which replaced the ozone-depleting freon R-12. New models increasingly use isobutane R-600a, which has excellent cooling performance, but is explosive.
⚠️ Attention: If your refrigerator runs on isobutane (R-600a), any soldering and filling work requires special care. A spark from a blowtorch or an electrical discharge can lead to an explosion of gas accumulated in the chamber.
You can determine the type of gas by looking at the sticker on the compressor or technical documentation. R-134a requires synthetic oil, which does not absorb moisture as aggressively as mineral oil. For R-600a special mineral oils are used, and the system must be absolutely sealed.
It is important to understand that mixing different types of refrigerants is strictly prohibited. This will lead to the formation of acidic compounds, which will damage the compressor within a few weeks. If you are not sure about the brand of gas, it is better not to risk it and call a specialist with an analyzer.
Necessary equipment and tools
High-quality refueling is impossible without a professional set of tools. Trying to use artisanal methods often leads to repeated breakdowns after a short time. You will need not only a gas cylinder, but also devices for monitoring the pressure and cleanliness of the system.
The central element of the set is vacuum pump. It is necessary to remove air and moisture from the circuit before refueling. Residual moisture inside the system is the main enemy of the refrigerator, since water freezes in the capillary tube, forming an ice plug.
You will also need a pressure gauge manifold station that allows you to control the pressure at the inlet and outlet. To fill by weight, you need electronic scales with high accuracy. Charging “by eye” or by pressure for household refrigerators is unacceptable due to the small volume of the system.
Don't forget to prepare tools for soldering copper tubes. This could be a gas torch with solder or a special soldering iron for copper pipes. It is necessary to have cutters, a pipe cutter and a rolling machine if sections of the line need to be replaced.
Preparation of the system and removal of old freon
The first stage of work is the dismantling of the old refrigerant. You cannot simply puncture the tube and release the gas into the room, especially if there are people or pets there. The process must be controlled.
First you need to gain access to the service fitting or process tube. If there is no fitting, it must be carefully welded or soldered into the cut copper tube on the suction pipe of the compressor. The soldering area must be cleaned and treated with flux.
Next, a pressure gauge station is connected to the fitting. By opening the valve, you release the remaining gas. At this point, oil may be leaking through the system, so have a container ready to catch it. The color and smell of the oil can tell a lot about the condition of the compressor: if it is black and smells like burning, the unit is most likely burned out.
After releasing the pressure, the system is purged with nitrogen. This allows you to displace the remnants of old freon and moisture. Nitrogen is supplied under slight pressure and then released. The procedure is sometimes repeated twice to ensure the cleanliness of the circuit.
The process of vacuuming the refrigeration circuit
Evacuation is the most important stage on which the durability of the repair depends. The goal is to reduce the system pressure to a minimum, which will cause the moisture to boil and evaporate at room temperature.
Connect the vacuum pump to the low pressure service port (usually blue on the station). Turn on the pump and watch the pressure gauge needle. The pressure should drop to minus values. The operating time of the pump depends on the power of the equipment, but usually ranges from 30 minutes to 1 hour.
There is a common misconception that you only need to vacuum for a couple of minutes. This is a big mistake. The moisture in the oil and on the walls of the tubes will not have time to evaporate. Vacuuming must be prolonged to ensure the removal of microscopic water particles.
| Parameter | Normal | Critical value |
|---|---|---|
| Residual pressure | less than 300 microns | more than 500 microns |
| Evacuation time | 30-60 minutes | less than 10 minutes |
| Vacuum stability | The arrow is standing | The arrow is creeping up |
After turning off the pump, it is necessary to close the valve and monitor the behavior of the pressure gauge needle for 15-20 minutes. If the arrow creeps up, it means that there is a leak in the system, and you need to look for the leak again. Only a stable vacuum gives the right to the next stage.
Why can’t you refuel without a vacuum sealer?
Residual air in the system creates excess pressure, increasing the load on the compressor. The moisture remaining inside will freeze in the capillary tube, completely blocking the circulation of freon after a few hours of operation.
Technology for refilling the refrigerator with freon
Refilling is carried out strictly according to the weight indicated on the compressor nameplate. Deviations of even 10-15 grams can lead to incorrect operation. The freon cylinder is installed on electronic scales, which are calibrated (zeroed) taking into account the weight of the hoses.
Open the valve on the cylinder and let gas into the system. On the scale you will see the grams begin to decrease. As soon as the value reaches the required value, close the valve. Liquid freon fills the condenser and capillary tube.
☑️ Refilling checklist
There is a method of filling by pressure, but it is applicable only in extreme cases and requires a lot of experience. The pressure in the system depends on the ambient temperature, so relying only on a pressure gauge is risky. For R-134a and R-600a the weight method is the only correct one.
After refueling, start the compressor and let it run for 10-15 minutes. At this time, check the uniformity of heating of the condenser (grid at the back) and the appearance of cold in the evaporator. If everything went well, seal the service tube.
⚠️ Attention: When sealing the service tube, be sure to close the valve on the cylinder and remove the hose from the fitting. Otherwise, the remaining gas under pressure may ignite from the burner flame.
Typical mistakes and safety measures
Independent repair of refrigerators is fraught with risks. One of the main mistakes is using an open fire in an unventilated area. Freon vapor is heavier than air and can accumulate near the floor, creating a suffocating atmosphere.
Another common mistake is insufficient vacuuming time. Equipment owners save time by relying on “maybe”. As a result, after a week the refrigerator stops freezing again due to an ice plug in the capillary, and the procedure has to be repeated.
Working with electricity and gas equipment requires sobriety and attention. Do not carry out repairs if you are tired or stressed. Also, do not use damaged hoses or pressure gauges with an expired verification period.
If you overheat the tube during the soldering process, the copper can oxidize from the inside, creating scale. These particles will subsequently enter the compressor and cause it to jam. Therefore, it is important to observe the temperature regime and use flux.
Is it worth doing the filling yourself?
The answer to this question depends on your technical training and the availability of equipment. Buying a vacuum pump, station and scales will cost more than calling a specialist once. However, if you plan to repair equipment professionally, the investment is justified.
For a one-time refill of one refrigerator, it is more rational to contact a service center. Craftsmen have access to original spare parts, know the nuances of specific models Indesit, Bosch or LG and provide a guarantee for their work.
Independent repair makes sense if you already have soldering skills and understand the principles of the refrigeration cycle. Otherwise, there is a high risk of permanently destroying expensive equipment by adding a burnt compressor to the leak.
Remember that modern refrigerators are complex electronically controlled units. An error in the mechanical part can lead to failures in the electronic module. Weigh all the pros and cons before starting work.
Is it possible to fill a refrigerator with freon without a vacuum pump?
It is technically possible to blow out the system and refill it without a vacuum pump, but this is a “collective farm” method. Without a deep vacuum, moisture will remain in the system, which will quickly cause corrosion and ice blockage. The service life of the compressor during such repairs will be reduced significantly.
Which freon is better: R-134a or R-600a?
It is incorrect to compare them, since they are intended for different systems. R-600a (isobutane) is more environmentally friendly and economical, but is explosive. R-134a is safer in terms of ignition, but requires higher pressure and expensive synthetic oils.
Why does the refrigerator freeze after refueling, but does not turn off?
Most likely, the gas dosage is incorrect. If there is a lack of freon, the compressor works non-stop, trying to gain temperature, but cannot cope. If there is excess pressure in the system, the pressure in the system increases, and the thermostat cannot open the circuit.
Is it necessary to change the oil in the compressor when refueling?
During scheduled refueling due to a leak, the oil does not need to be changed if it has not turned black and does not have a burning smell. The oil is replaced only when the compressor burns out or switches to another type of refrigerant that requires a different chemical base of lubrication.
Where can I get the exact weight of the refill for my model?
The exact amount of refrigerant is indicated on the factory sticker (nameplate), which is usually located on the back wall of the case or inside the refrigerator compartment. Also, this data is in the technical documentation (passport) of the device.