Sudden stoppage of operation of the refrigeration unit often becomes an unpleasant surprise, especially when the cells contain perishable products. Before calling a technician or proceeding with complex manipulations, you need to understand the essence of the problem: most often, the lack of cold indicates a refrigerant leak. The process of restoring the functionality of the system, commonly referred to as “refueling,” requires not only special knowledge, but also a strictly defined set of tools and consumables.
An inexperienced owner may think that it is enough to simply buy a gas cylinder and connect it to the tube. However, the reality is that sealing the system evacuation plays an even more important role than the volume of the poured substance itself. Without creating a deep vacuum, moisture and air will remain inside the circuit, which will lead to the formation of acids and rapid failure of the compressor. That is why preparation for the procedure begins long before connecting the hoses.
In this article we will analyze in detail what exactly is included in the necessary arsenal of a refrigeration equipment repair specialist. You will learn about the types of refrigerants, the characteristics of oils and the specifics of tools, without which high-quality refilling is impossible. Understanding these nuances will help you make an informed decision: take on the repair yourself by purchasing equipment or entrust the task to professionals who have all the necessary tools.
Required set of professional tools
The basis for carrying out any work on the refrigeration circuit is a collector station, or, as it is often called, a pressure gauge station. This device allows you to control the pressure in the system, which is critical for proper refueling. The station consists of two pressure gauges (high and low pressure) and a block of valves to which hoses are connected. For household repairs, universal stations that work with various types of freons are most often used.
The second irreplaceable element is vacuum pump. Its task is to remove air and moisture vapor from the system before refueling. Residual moisture inside the circuit, upon contact with refrigerant and oil, forms aggressive compounds that destroy the metal and insulation of the compressor windings. The pump must provide a residual pressure close to absolute vacuum to guarantee the durability of the repair.
You will also need auxiliary tools for mechanical processing of tubes:
- 🔧 Pipe cutter - provides a perfectly even cut of a copper pipe without the formation of chips inside.
- 🔥 Torch (gas or oxygen-acetylene) for soldering joints.
- 🧹 Cleaners and brushes for cleaning pipes before soldering.
- 🗜️ Rolling set for creating sealed joints on copper pipes.
⚠️ Attention: Using a conventional hair dryer instead of a specialized torch for soldering copper pipes is unacceptable, since the melting temperature of solder is much higher than the capabilities of household heating devices.
Do not forget about personal protective equipment. Working with gas under pressure and open flame requires caution. Be sure to use safety glasses and gloves to prevent burns and contact of refrigerant with the skin, which can cause frostbite.
Types of refrigerants and choosing the right freon
The central element of any refrigeration system is the refrigerant - the working fluid, which, circulating along the circuit, transfers heat. To refill the refrigerator, you need to know exactly what type of gas was used by the manufacturer. Mixing different types of freons is strictly prohibited, as this changes the thermodynamic properties of the mixture and can lead to an explosive situation or compressor breakdown.
The most common types of refrigerants in modern and recent models are:
- ❄️ R600a (Isobutane) —natural hydrocarbon gas with excellent refrigeration properties. It is a fire hazard, so it requires special care when refueling and the absence of sparking elements nearby.
- 🌿 R134a (Tetrafluoroethane) is a synthetic freon that replaced the ozone-depleting R12. It is non-flammable, but requires the use of synthetic oil.
- 🏭 R12 (Freon-12) is an outdated type, found in very old Soviet and imported refrigerators. Its use is now limited by environmental standards.
Choosing the right cylinder is only half the battle. On the back wall of the refrigerator, on a special sticker (nameplate), the type of refrigerant and its exact amount in grams are always indicated. A deviation from the norm, even 10-15 grams, can significantly affect the efficiency of the unit.
Why can’t you mix R600a and R134a?
These gases have different chemical structures and require different types of oils to lubricate the compressor. Mixing will lead to the formation of sediment, blockage of the capillary tube and loss of lubricating properties, which is guaranteed to damage the compressor in a short time.
When purchasing a cylinder, pay attention to the presence of a valve. Disposable cylinders often do not have threads, and to work with them you will need a special adapter or piercer, which is less convenient and airtight than using reusable ventilated cylinders.
Oils for refrigeration compressors
Many people forget that not only gas circulates inside the system, but also oil, which lubricates the rubbing parts of the compressor. If freon leaks, some of the oil may also leave the system or remain in the evaporator. When replacing a compressor or major repairs involving flushing the system, it is necessary to add or completely change the oil. The main rule: the oil must be compatible with the type of refrigerant used.
There are two main types of oils used in household appliances:
- Mineral oils —traditionally used with R12 freons. They have good lubricity, but do not mix well with modern refrigerants.
- Synthetic oils (PAO, Essential/POE) are required for use with freon R134a and R600a. They are hygroscopic, that is, they actively absorb moisture from the air, so they need to be stored in a tightly closed container.
If you are replacing a compressor, the new unit may already be filled with oil. However, if you change the filter drier or flush the circuit, the oil level may drop. In such cases, topping up is carried out through the compressor process pipe before evacuation begins.
⚠️ Attention: Never open a container with synthetic oil in advance. Once in an open vessel, it immediately begins to absorb moisture from the atmosphere, which in the refrigerator system will lead to the formation of ice plugs in the capillary.
Consumables and system sealing
The quality of the filling directly depends on the tightness of the connections. Any microscopic crack or poor-quality soldering will lead to a repeated gas leak after a few months or even weeks. Therefore, the list of required materials should include only proven components.
The table below shows the main consumables and their purpose:
| Material | Purpose | Features |
|---|---|---|
| Solder (with silver) | Soldering of copper pipes | Provides a strong and tight connection, the melting point is higher than that of tin. |
| Flux (borax) | Protection against oxidation | Prevents the formation of an oxide film when heating copper, facilitates the spreading of solder. |
| Filter-dryer | Cleaning the system | Required to be changed each time the circuit is opened, removes moisture and pollution. |
| Copper pipe | Increasing the circuit | Only annealed copper pipe in coils, soft and flexible, is used. |
Special attention should be paid to the filter drier. This is a cylindrical element installed in front of the capillary tube. Inside it is zeolite or silica gel, which absorbs moisture. When the system is opened (for example, to replace a compressor or eliminate a fistula), the old filter loses its properties and must be replaced. Trying to “calcinate” an old filter in the oven will not return it to its factory properties.
For soldering, use solder containing silver (for example, 15% or 30%). Pure copper or brass is soldered with refractory solders, but it is silver that provides the necessary elasticity to the seam, which is important for systems operating under constant compressor vibration.
Evacuation process and quality control
After repair work, soldering and replacement of components, the most critical stage begins - vacuumization. This is the process of removing air and moisture from the circuit. Water in the system in the form of steam freezes at low temperatures and can completely block the lumen of the capillary tube, stopping the circulation of freon.
The process is as follows: a hose from a vacuum pump is connected to the service pipe. The pump turns on and runs for 20-40 minutes (the time depends on the power of the pump and the volume of the system). The low pressure gauge should show a value in the “green zone” or go into vacuum (negative value). After turning off the pump, turn off the valve and watch the pressure gauge needle for another 15-20 minutes. If the arrow remains in place, the system is sealed. If the pressure increases, there is poor-quality soldering somewhere.
☑️ Checklist before refueling
Only after successfully passing the vacuum test can you begin refueling. Gas is introduced into the system in small portions while the compressor is running, controlling the current consumption of the electric motor and the temperature of the condenser.
Safety precautions when working with gas
Working with refrigeration equipment is associated with certain risks. Refrigerants, when under pressure, can cause injury, and some of them (for example, R600a) form an explosive mixture in high concentrations in the air. Therefore, compliance with safety precautions is not just a recommendation, but a mandatory requirement.
Basic rules for safe work:
- 💨 Ensure good ventilation of the room, especially if you work with isobutane (R600a).
- 🚭 Smoking or using open fire is strictly prohibited (except for the burner) in the immediate vicinity of the refueling site.
- 🧤 Use safety glasses to prevent a jet of gas or oil under pressure from getting into your eyes.
- 🌡️ Do not heat freon cylinders above 40-50 degrees Celsius.
It is also worth remembering soldering temperature. Copper has high thermal conductivity, and heat can spread to the plastic elements of the refrigerator body or wire insulation. Always use heat shields (metal plates) when soldering tubing in close proximity to the housing.
⚠️ Attention: Equipment specifications, types of refrigerants used, and safety standards may be updated by manufacturers. Always check the official technical documentation for a specific refrigerator model before starting work.
Frequently asked questions (FAQ)
Is it possible to fill the refrigerator with regular car freon?
No, it is not possible. Car air conditioners most often run on R134a freon, but R600a is also widely used in refrigerators. These gases are not interchangeable. In addition, the oils in the systems may differ. Using the wrong gas will lead to compressor failure.
How long does the refueling procedure take?
Professional refueling with all stages (search for leaks, soldering, evacuation, refueling) takes from 1.5 to 3 hours. The process of pumping gas is quick, but preparing the system and checking the tightness takes time.
Why does the refrigerator freeze worse after filling?
There may be several reasons: incorrect amount of freon charged (underfilling or overfilling), the presence of an air lock, contamination of the system or poor-quality vacuuming, which left moisture in the circuit.
Is it necessary to change the compressor if there is a freon leak?
Not always. If the compressor is working properly (it closes, hums, creates pressure), then there is no need to change it. It is enough to find the leak, seal it, replace the filter drier and refill the system. The compressor is replaced only if it has a mechanical or electrical malfunction.