The situation when the refrigerator stops freezing, and an unpleasant smell appears inside or, conversely, complete silence, always takes you by surprise. Often the cause is a refrigerant leak, and the owner is faced with the question of whether to call a technician or try to solve the problem on his own. Refilling with freon is a technically complex process that requires an understanding of the principles of operation of the refrigeration circuit and the availability of special tools, but theoretically feasible for an experienced home craftsman.
Before taking active steps, you must clearly understand the risks. Improper refueling or moisture entering the system can permanently damage the unit, turning a simple repair into an expensive compressor replacement. In this article, we will analyze in detail the stages of preparation, leak detection and direct refueling, so that you can weigh your strengths.
It is worth noting that modern models, such as Indesit, Atlant or Bosch, may have design features that affect access to the tubes. It is important not only to know how to connect the cylinder, but also to understand why the system lost its tightness. Without eliminating the cause of the leak, any refill will only be a temporary measure that will require repeating in a few weeks.
Diagnostics and search for refrigerant leaks
The first and most important step is to confirm the fact of the leak. If the compressor runs constantly without turning off, and the temperature in the chambers does not drop below room temperature, this is a sure sign of shortage refrigerant. However, before starting work, you need to make sure that the problem is in the gas, and not in the thermostat or a clogged capillary. A visual inspection of the system often helps to identify places of depressurization.
The most common places of leaks are in the foamed part of the housing or in places where pipes are soldered. To accurately determine the location of the gas exit, professionals use leak detectors, but at home you can use a soap solution. Apply it liberally to all accessible connections, evaporator and condenser, and watch closely for bubbles.
⚠️ Attention: If you find a leak in the foamed part (inside the walls of the housing), independent repair is almost impossible without compromising the integrity of the thermal insulation. In such cases, it is often necessary to call a specialist or install an external evaporator (“crying cap”).
After detecting and eliminating mechanical damage (by soldering or replacing the unit), the system must be purged with nitrogen under pressure. This is a critical procedure to remove moisture and old oil residue. The pressure during purging should be about 10-15 atmospheres, which allows you to identify weak soldering points before refueling.
Necessary tools and materials
To perform vacuuming and filling work efficiently, you will need specialized equipment. Just buying a gas cylinder from a store is not enough; you need a whole set of tools that will ensure tight connections and dosage accuracy. The absence of even one element can lead to failure of the entire operation.
The main tool is a vacuum pump, which is necessary to remove air and moisture from the circuit. Without a deep vacuum, the remaining moisture in the system will freeze in the capillary tube, forming an ice plug that blocks the circulation of freon. You will also need a pressure gauge station (manifold) to monitor the pressure in the system.
- 🛠️ Vacuum pump —a device for creating a vacuum in the circuit.
- 📟 Gauge manifold —for measuring pressure and connecting hoses.
- ⚖️ Electronic scales —necessary for accurately weighing the amount of gas being charged.
- 🔥 Torch and solder —to seal the system after filling (if there is no Schrader valve).
In addition, you you will need the refrigerant itself. The type of freon is always indicated on a label located on the back wall of the refrigerator or inside the chamber. The most commonly used brands are R134a or R600a. Using the wrong type of gas is strictly prohibited, as this will lead to improper operation of the compressor and possible failure.
Preparing the refrigerator for refueling
Before starting any manipulations with the refrigeration circuit, the unit must be completely defrosted and dried. Moisture is the main enemy of the cooling system. After defrosting, it is necessary to gain access to the compressor process tube, which is usually sealed. It is through this that the equipment will be connected.
If a Schrader valve (filling valve) is already installed on the tube, the task is simplified. If the tube is sealed, you need to carefully bite it or saw it, avoiding chips getting inside. At this stage, it is important not to damage the copper tube itself or deform it, as this will complicate subsequent soldering.
☑️ Preparation for refilling
Next, you need to solder the service valve to the tube. For this, a brass fitting is used, which is put on the tube and sealed with soft solder. The quality of soldering here plays a decisive role: the connection must withstand high pressure without the slightest sign of gas etching.
⚠️ Attention: When working with an open flame near the plastic elements of the refrigerator, be extremely careful. Use a metal screen or a wet rag to protect the plastic from melting.
After installing the valve, the system is assembled into a single circuit: compressor - valve - pressure gauge station - vacuum pump. Only after checking the tightness of all connections can you proceed to the next stage - evacuation.
The process of evacuation of the system
Evacuation is the process of removing air, moisture and non-condensable gases from the refrigeration circuit. The presence of air in the system increases the condensing pressure, which causes the compressor to work overload and reduces cooling efficiency. Moisture, combining with oil and freon, forms acid, which destroys the engine windings.
The process is as follows: the hose from the vacuum pump is connected to the corresponding port of the pressure gauge station. After turning on the pump, the pressure gauge needle should begin to confidently move towards negative values (towards the vacuum zone). The operating time of the pump depends on the power of the equipment and the volume of the system, but usually ranges from 15 to 30 minutes.
| Parameter | Normal value | Tolerable deviation |
|---|---|---|
| Residual pressure | less 0.1 mbar | up to 0.5 mbar |
| Evacuation time | 20-30 minutes | depends on the pump |
| Oil temperature in pump | Not higher than 60°C | Control visually |
It is important to monitor the condition of the oil in the sight glass of the vacuum pump. If the oil begins to bubble or change color (becomes milky), this indicates intense evaporation of moisture from the system. In this case, the procedure may have to be interrupted, replace the oil in the pump and continue the process.
Why can’t you skip the vacuum step?
If moisture is not removed, it will freeze in the narrowest part of the system - the capillary tube. This will lead to the formation of an ice plug, which will block the circulation of freon. The refrigerator will stop freezing, and the compressor will work hard, trying to push through this plug. In addition, moisture causes corrosion of internal parts.
Technology for filling a refrigerator with freon
After successful evacuation, the valve on the pump is closed, and the station switches to the refrigerant cylinder. Refilling is carried out strictly by weight, since volumetric methods (by eye or by time) do not guarantee correct operation. The filling rates are indicated on the refrigerator's factory tag (usually from 30 to 150 grams).
The freon cylinder is installed on the scale, and the hose from the station is connected to it. By opening the valve on the cylinder, gas begins to flow into the system. At this point the compressor should be started. Liquid freon, entering the operating compressor, boils, and the pressure in the system begins to increase.
- 💧 Weight control —monitor the scale readings so as not to exceed the norm.
- 🌡️ Condenser temperature —the grill at the back should heat up evenly.
- ❄️ Evaporator cooling —check the appearance frost in the freezer.
- 🔊 Compressor sound —it should operate smoothly, without gurgling.
During the refueling process, it is necessary to constantly monitor the pressure on the low pressure gauge. It differs for different types of freon. For example, for R134a the working suction pressure is usually 0.05–0.08 MPa, and for R600a it is negative or close to zero. The exact values depend on the ambient temperature.
When the required amount of gas has been collected, the valve on the cylinder overlap. The pressure in the system stabilizes. Now the most important thing is to seal the filling tube tightly. To do this, clamp the tube with a clamp (or use punching) and seal it with a torch, after which the pressure gauge station is removed.
Checking functionality and typical errors
After soldering is completed and the connection point has cooled, the refrigerator is turned on to the network for the final check. The main criterion for success is uniform cooling of the chambers and proper shutdown of the compressor when the set temperature is reached. The process of entering the mode can take from 2 to 5 hours.
A common mistake for beginners is an overdose of freon. If there is too much gas, liquid refrigerant can enter the compressor, causing water hammer, which is fatal to the mechanism. Also, excess gas leads to increased condensation pressure and overheating of the unit. The lack of freon, in turn, does not provide the required cooling capacity.
⚠️ Attention: When filling with isopentane (freon R600a), exercise maximum caution! This gas is explosive. All work should be carried out in a well-ventilated area, away from open flames and sparking devices.
Another common mistake is poor soldering quality. Microcracks in the seams can allow gas to pass through for months, creating the illusion of a successful repair. Use high-quality solder and flux, and also monitor the melting temperature so as not to burn out the copper.
If after refueling the refrigerator is noisy, does not turn off, or only partial frost forms on the back wall, then the technology has been broken. In this case, the system will have to be opened again, the gas pumped out and the procedure repeated in compliance with all standards.
Questions and answers (FAQ)
Is it possible to fill a refrigerator with freon without a vacuum pump?
Theoretically, you can try the displacement method, when air is squeezed out with gas, but this highly not recommended. Residual moisture in the system will quickly lead to the formation of an ice plug in the capillary tube and failure of the compressor. Evacuation is a mandatory step for long-term repairs.
Which freon is better: R134a or R600a?
It is impossible to say which gas is “better”, since each refrigerator is designed for a specific type of refrigerant. R600a (isobutane) is more environmentally friendly and requires less quantity substances, but it is explosive. R134a safer, but requires higher pressure in the system. It is impossible to replace one type with another without altering the entire system (compressor, oil, capillary).
Why does the refrigerator freeze after refueling, but does not turn off?
Most likely, there is a leak in the system and the gas comes out again. The second reason is a clogged capillary tube or filter drier, or the presence of an air lock. It is also possible that the amount of freon was selected incorrectly (underfilling). Repeated diagnostics with a pressure gauge is required.
Is it necessary to change the filter drier when refueling?
Yes, this is a mandatory rule. The filter drier is a disposable element. After opening the circuit, it absorbs moisture from the air and loses its properties. Installing an old filter guarantees the rapid formation of an ice plug and breakdown.