Many owners of household appliances are wondering what gas to fill in the refrigerator when the unit stops freezing. This is a critical point as using the wrong refrigerant can cause compressor failure or even system explosion. In everyday life, different brands of freons are often confused, considering them universal, which is a gross mistake.
Modern refrigeration units operate on different types refrigerants, each of which has unique chemical properties and pressure requirements. The wrong choice of substance will not only reduce the cooling efficiency, but will also disrupt the operation of the oil in the compressor, causing it to jam.
Before looking for a gas cylinder, you need to accurately determine the type of system installed in your refrigerator. Manufacturers indicate this information on a special plate, and it cannot be ignored. In this article we will look at the main types of gases, their compatibility with oils and the consequences of errors when filling.
Main types of refrigerants in household refrigerators
Historically, many different substances were used in refrigeration technology. However, in modern household models, only two or three types of gases dominate. The most common in old and many modern models is R134a (tetrafluoroethane). This is an environmentally safer replacement for freon R12, which was banned due to its destructive effect on the ozone layer.
The second popular type is R600a (isobutane). It is a hydrocarbon gas that has excellent refrigerating properties but is flammable. That is why increased safety requirements are imposed on the repair of isobutane refrigerators. The pressure in a system with R600a is lower than in R134a, but the volumetric refrigeration capacity is higher.
There are also mixtures such as R406a or R507, but they are more often used in industrial equipment or as repair substitutes. It is important for the household user to know: if your refrigerator originally ran on R134a, you cannot just fill it with R600a without completely reworking the system and changing the oil.
⚠️ Attention: R600a (isobutane) is explosive at a concentration in air of more than 1.3%. Work on refilling such refrigerators should be carried out in a well-ventilated area, away from sources of open flame and sparks.
Is it possible to mix different freons?
Mixing different types of refrigerants (for example, R12 and R134a) is strictly prohibited prohibited. This leads to the formation of acids that destroy the motor windings and a change in pressure, which disables the compressor.
How to determine what kind of freon is in your refrigerator
Determining the type of refrigerant is the first step before any repair. Manufacturers are required to apply markings to the device body. Most often, the information plate (nameplate) is located inside the refrigeration chamber on the side wall or on the rear panel of the unit.
On the plate you are interested in the column Refrigerant or Refrigerant. The code will be indicated there, for example R-134a or R-600a, as well as the amount of the substance in grams. This amount is critical for proper priming. It may also indicate the type of oil compatible with this freon.
If the plate is erased or missing, you can focus on the year of manufacture and manufacturer. European models after 2010 most often run on isobutane. Soviet refrigerators and many old imported models were used R12. However, relying only on the year of manufacture is risky - always look for physical marks on the pipes or compressor.
In some cases, especially with deep modernization, the type of gas may have been changed by previous masters. Then it helps to analyze the pressure in the system and the type of oil used, but this is already a task for a professional with a pressure gauge station.
Compatibility of oils and refrigerants
The choice of gas is inextricably linked with the type of oil circulating in the system. The refrigerator compressor is lubricated with oil, which must dissolve in the refrigerant and return back to the crankcase. If you fill in the wrong gas, the oil will precipitate or thicken.
For freon R134a and R600a synthetic oils like PAG (polyalkylene glycol) or POE (polyester). These oils are hygroscopic, that is, they actively absorb moisture from the air, which requires special care during repairs. In contrast, the old R12 worked with mineral oils, which are not so afraid of moisture, but are incompatible with the new freons.
An attempt to fill the system with R134a, leaving the mineral oil from R12 in it, will cause the mixture to turn into paraffin. The compressor will start to overheat and quickly fail. A complete oil change and flushing of the system is a prerequisite when switching to another type of refrigerant.
| Refrigerant type | Type of compatible oil | Working pressure (approximately) | Danger |
|---|---|---|---|
| R12 | Mineral | Low | Destroys ozone |
| R134a | Synthetic (PAG/POE) | Average | Safe |
| R600a | Mineral / Synthetics | Low | Explosive |
| R406a | Mineral / Alkylbenzene | Average | Toxic at combustion |
Refilling standards and necessary tools
The amount of gas that needs to be filled into the refrigerator is measured to the nearest gram. A lack of freon will cause the refrigerator to work non-stop, not reaching the set temperature. Excess gas will cause high pressure in the condenser, overload of the compressor and possible rupture of the tubes.
For accurate refueling, it is not enough to simply release gas by eye. An electronic scale capable of measuring tenths of a gram and a manometer are required. The process looks like this: first, the system is evacuated, then the gas cylinder is weighed, and a strictly measured amount of substance is released into the system.
The filling rate is always indicated on the nameplate. For example, the inscription R600a 50g means that there should be exactly 50 grams of isobutane in the system. A deviation of more than 5 grams can significantly affect the operation of the unit.
☑️ Tools for refilling
If you use hoses with a pressure gauge, air or residues of another gas remain in them. Therefore, professionals always purge the hoses before connecting to the system, releasing a small stream of freon.
Dangers and consequences of errors when refueling
Incorrect refueling is not just “the refrigerator does not freeze.” This risks costly repairs or complete replacement of the compressor. One of the most common mistakes is using gas at the wrong pressure. For example, if R134a is pumped into a system designed for low pressure R600a, the pressure at the outlet of the compressor will increase significantly.
This will lead to rupture of the condenser welds or damage to the compressor valves. In addition, different freons have different thermal conductivity and boiling points. The wrong gas can cause freezing of the evaporator in the wrong places or, conversely, insufficient cooling.
⚠️ Attention: Never use car freons or lighter gas as a replacement! They contain impurities that will instantly damage the refrigerator and can be hazardous to health.
Another danger is moisture ingress. As mentioned, modern oils are hygroscopic. The water in the system freezes in the capillary tube, forming an ice plug. The refrigerator starts working cyclically: it freezes for 10 minutes, then sits for an hour until the plug thaws. This can only be cured by a complete refill with replacement of the filter-drier.
Frequently asked questions and myths about freon
There are many myths surrounding gases for refrigerators. You can often hear that “freon needs to be renewed every 5 years,” like the oil in a car. This is a lie. Refrigerant in a closed loop it is not consumed if the system is sealed. If the gas has disappeared somewhere, it means that a leak has formed that needs to be found and eliminated.
Another myth says that you can simply “pump up” the gas without knowing the brand. This cannot be done efficiently. Mixing gases changes their physical properties, and the behavior of such a “cocktail” cannot be predicted. The compressor may burn out in a week or a month.
There is also a misconception that the more gas, the better the cooling. In fact, an overfilled condenser dissipates heat worse and the system efficiency drops. Accurate adherence to the grammage is the key to the long life of the refrigerator.
Professional repair or do-it-yourself refueling?
Refilling the refrigerator requires not only gas, but also special tools: a vacuum pump, scales, a torch for soldering copper pipes. The cost of equipment often exceeds the cost of calling a technician. In addition, working with the flammable R600a requires skills and compliance with safety precautions.
An independent attempt to refuel without vacuuming is doomed to failure. Air and moisture remaining in the system will quickly kill the compressor. If you do not have experience in soldering copper pipes and working with refrigeration equipment, the risk of damaging the equipment is very high.
A professional technician will not only fill the required gas, but also check the system for leaks, replace the filter drier (which is mandatory when opening the circuit) and monitor the current consumption of the compressor. This ensures that the refrigerator will work for many more years.
What happens if you fill the refrigerator with lighter gas?
Lighter gas (usually a propane-butane mixture) is chemically similar to R600a, but is not purified to refrigeration levels. It contains impurities that can coke the capillary tube and destroy the insulation of the compressor windings. In addition, the vapor pressure of propane-butane at room temperature is significantly higher than that of freon, which can lead to a rupture of the system.
Why did the refrigerator stop freezing after refueling?
There may be several reasons: moisture ingress (ice jam), incorrect amount of gas (too little or too much), use of incompatible oil or freon, as well as the presence of air in system (air lock in the condenser). It is also possible that during soldering the tube overheated and internal carbon deposits formed, blocking the flow of the refrigerant.
Is it possible to mix R134a and R600a?
It is absolutely not possible. This will lead to a chemical reaction, breaking down the oil and producing acids. The compressor will fail very quickly. If there was one gas in the system, and you filled in another without flushing, the system is awaiting a major overhaul.
How often do you need to change freon in the refrigerator?
Freon never needs to be changed if there is no leak in the system. It's a vicious cycle. If the gas disappears, it means the seal is broken. Simply “adding” freon is a temporary solution, since gas will come out again through the hole, and with it the oil, which will kill the compressor.
⚠️ Attention: Prices for refrigerants and services of service centers may vary. Before starting work, check the current cost of gases R600a and R134a from suppliers, as they are quota-regulated substances.