Self-refueling of the refrigerator refrigerant is a technically complex process that requires not only specialized equipment, but also a deep understanding of thermodynamics compressor operation. Unlike replacing a lamp or adjusting a door, tampering with a sealed circuit carries the risk of damaging compressor or violating environmental standards. Many owners of household appliances mistakenly believe that it is enough to simply add gas, but the system requires complete removal of the old substance and air.
Before getting started, you need to realize that different models of refrigerators, be it Indesit, Atlant or Bosch, use different types freon, each of which has its own chemical properties and pressure in the system. Incorrect selection of refrigerant can lead to fire (in the case of propane-butane mixtures) or rapid failure of the compressor due to a mismatch in oil viscosity. In this article we will analyze all stages of the process, from finding a leak to the final control of the operation of the unit.
It is important to understand that without sealing the circuit and eliminating the cause of the leak, any refill will only be a temporary measure. The refrigerator will stop freezing after a few days or weeks when the gas escapes again through the microcrack. Therefore, the first step is always diagnosis, not searching for a gas cylinder. Only after making sure that the tubes are intact can you proceed to technical manipulations.
Diagnostics of leaks and preparation of equipment
The first stage of work is to accurately determine the location where the depressurization occurred. Often a leak occurs in the foamed part of the housing or at the connection evaporator with the compressor. To search, use a soap solution or special electronic leak detectors that react to refrigerant vapors. If bubbles do not appear, perhaps the system has been empty for a long time, and the pressure inside has become equal to atmospheric pressure.
To carry out the work, you will need a professional set of tools that cannot be replaced with household analogues. Critical elements are the vacuum pump, gauge station (manifold) and scale for accurate dosing. Without evacuation, the system will remain contaminated with moisture and air, which will lead to the formation of ice plugs in the capillary tube.
⚠️ Attention: The use of an open flame to find leaks in refrigerators operating on R600a (isobutane) is strictly prohibited due to the high explosiveness of this gas.
Preparation of the workplace also includes ensuring good ventilation. Refrigerants are heavier than air and can displace oxygen in a room, creating a suffocation risk if large volumes leak. In addition, some old types of freons, upon contact with an open flame, emit phosgene, a chemical warfare agent.
Types of refrigerants and their features
Modern household appliances mainly use two types of refrigerants: R134a and R600a. The first is tetrafluoroethane, which is a safe analogue of the prohibited one. It is non-toxic and non-flammable, but has high pressure in the system, which requires durable pipes and high-quality oil. Refilling with such gas requires strict pressure control. R12. It is non-toxic and non-flammable, but has high pressure in the system, which requires durable pipes and high-quality oil. Refilling with such gas requires strict pressure control.
The second type, R600a (isobutane), is a hydrocarbon mixture. Its main advantage is high energy efficiency and environmental friendliness. However, it ignites at concentrations in air ranging from 1.3% to 8.5%. The amount of such gas in the system is usually small (about 30-60 grams), but special care is required during repairs. It is impossible to confuse the types of freons: oil for R134a (synthetic POE) and for R600a (mineral) are chemically incompatible.
There is a correspondence table that helps technicians navigate the compatibility of oils and refrigerants. Violation of these rules leads to the formation of acids inside the system, which corrode the windings of the compressor. of the electric motor. Refrigerant type. Chemical base. data-i="77">Oil type compressor.
| Refrigerant type | Chemical basis | Danger | Oil type |
|---|---|---|---|
| R134a | Halocarbon | Safe | Synthetic (POE) |
| R600a | Hydrocarbon | Explosive | Mineral |
| R12 | Freon (prohibited) | Destroys ozone | Mineral |
| R404a | Mixture | High pressure | Synthetic |
The process of vacuuming the system
Vacuuming is the most important stage, which is often ignored by amateurs. Its purpose is to remove air and, most importantly, water vapor from the circuit. Water entering the system freezes in the low-pressure zone (capillary tube), forming an ice plug that blocks the circulation of freon. In addition, moisture reacts with oil, forming aggressive acids.
The process begins by connecting the vacuum pump to the service fitting. The pump must run for a long time, usually from 30 minutes to several hours, depending on the degree of contamination of the system. To speed up the process and improve the quality of moisture removal, sometimes the “pushing” method is used: a little freon is briefly supplied to the system so that it mixes with the remaining moisture, and then everything is pumped out again with a pump.
⚠️ Attention: The residual pressure in the system after evacuation should be no more than 5-10 Pascal. If the pump does not hold vacuum and the pressure rises, then there is an active leak in the system that needs to be found and sealed.
While the pump is running, you can slightly warm up the compressor (for example, with a hairdryer) to evaporate the moisture stuck in the oil. However, this must be done carefully, without exceeding the temperature permissible for winding insulation. After pumping is complete, turn off the taps on the manifold, and only then turn off the pump so that oil from the pump does not flow back into the circuit.
☑️ Evacuation checklist
Refilling technology and dosage
After creating a deep vacuum, it’s time to refuel. Accuracy is critical here. The amount of refrigerant is indicated by the manufacturer on a technical sticker (nameplate), usually located inside the refrigerator compartment or on the back wall. The dosage is measured to the nearest gram, so the use of scales is mandatory. Modern refrigerators cannot be refilled by eye or by pressure, since the pressure depends on the ambient temperature.
Refilling is done in the liquid phase, if used R134a, or in the gas phase, if we are talking about R600a (so as not to overfill the compressor with liquid, which will cause water hammer). The cylinder is turned over or placed depending on the type of gas. Freon is released into the system in small portions, monitoring the weight on the scales. The compressor must be turned off.
When about 80% of the required volume has been reached, the compressor can be started. The remaining 20% is added to the operating system through the suction tube, monitoring the current consumption of the electric motor and the temperature of the condenser. Refilling It is dangerous because liquid freon can enter the compressor, causing valve knocking and destruction of the mechanical part.
Operation control and checking the tightness
After refueling, you need to let the refrigerator operate in test mode. At this time, the master monitors how the temperature rises evaporator and how the condenser grille at the back heats up. Uniform heating along the entire length of the condenser tubes indicates proper gas circulation. If only part is heated, there may be a lack of freon or a blockage.
It is imperative to re-check all soldered joints for leaks using a soap solution or a leak detector. The vibration of a running compressor could disturb the freshly made solder. The current consumption is also checked: it must correspond to the rating indicated on the compressor. An overestimated current indicates an overload (possibly too much gas), an underestimated current indicates an underload.
The final touch is to solder the service fitting. It is bitten off with pliers in the place where the copper tube remains, and quickly sealed with a burner so that air does not get inside. The soldering area is also checked for leaks.
⚠️ Attention: Technical characteristics of compressors and requirements for refrigerants may vary depending on the manufacturer and year of manufacture of the model. Always check the official documentation for a specific refrigerator model before starting work.
Common mistakes and consequences of incorrect refueling
One of the most common mistakes is refueling “by eye” or before the cold appears, ignoring the scales. This results in either too little or too much freon in the system. In the first case, the compressor runs non-stop, trying to reach temperature, and burns out from overheating. In the second, liquid refrigerant enters the compressor, causing water hammer, which physically breaks the valves.
Another fatal mistake is ignoring replacement filter-drier. This small element is responsible for cleaning freon from moisture and debris. When the circuit is opened, the filter becomes saturated with moisture from the air and loses its properties. If you install an old filter, moisture will quickly clog the capillary tube, and the refrigerator will stop cooling in a couple of days.
Also, novice craftsmen often neglect to flush the system with nitrogen before soldering. Copper oxides formed inside the tubes when heated by a burner can crumble and clog the thinnest channels of the capillary system. It is almost impossible to clean them later; a complete overhaul of the system is required.
Is it possible to fill a refrigerator with freon yourself without a scale?
Theoretically, you can navigate by current consumption and temperature, but this requires a lot of experience. For a home handyman without a scale, the result will be unpredictable: either the refrigerator will not freeze or the compressor will burn out. The risk of error is 90%.
How much does it cost to refill a refrigerator at the service?
The price consists of the cost of the work, the technician’s visit and the price of the refrigerant itself. On average, this costs less than buying a new refrigerator, but is more expensive than doing it yourself (except for the cost of purchasing equipment, which will pay for itself only after several repairs).
Why does the refrigerator freeze after refueling, but does not turn off?
Most likely, the dosage is incorrect (underfilling or overfilling), the system is contaminated with moisture (capillary tube) or the thermostat is faulty. Also, the reason may be a loss of housing tightness or leakage through the door seal.
Is it dangerous to breathe freon vapors?
Most modern freons (R134a, R600a) are not toxic under normal conditions, but in high concentrations they cause suffocation, displacing oxygen. When heated (welding), they break down into toxic components. R600a is additionally explosive.