Owners of Bosch appliances are often faced with a situation when the refrigerator stops freezing, and the first thought becomes the need to refuel. However, before looking for a service center, you need to find out exactly what exactly is being charged your model, since using the wrong substance can damage the compressor. Modern units of the German brand operate on different types of refrigerants, and they absolutely cannot be confused.
In this article we will analyze in detail the chemical composition of the working fluid, charging standards and technological features of the process. You will find out why R600a it differs from R134a not only in the formula, but also in the safety requirements for maintenance. Understanding these nuances will help you avoid costly diagnostic errors.
Some users mistakenly believe that freon is consumed during operation, like gasoline in a car, but this is not the case. Gas circulates in a sealed circuit for years, and its shortage indicates only depressurization of the system. Therefore, the question “what is being refilled with” should always be accompanied by the question “where is the leak.”
Types of refrigerants in Bosch equipment
Over decades of production, Bosch engineers have used various types of refrigerants, focusing on environmental standards and energy efficiency. Today, three main types of substances are most common, each of which has unique physicochemical properties. The choice of a specific gas depends on the year of manufacture of the model and its design features.
The most widespread in modern models is isobutane, indicated by the marking R600a. It is a hydrocarbon refrigerant that is highly energy efficient and has minimal impact on the ozone layer. However, it has one critical characteristic - flammability, which imposes special requirements on the filling procedure and soldering of pipelines.
In older models, as well as in some industrial series, tetrafluoroethane, known as R134a, was often found. This gas does not burn, but requires higher pressure in the condensing system compared to isobutane. The transition to new types of gases was dictated by international agreements prohibiting the use of freons, which destroy the ozone layer.
You can only determine whether your unit is charged by looking at the technical sticker. No external signs or year of purchase will give a 100% guarantee without visual confirmation. Always check this information before starting any work. what kind of freon your unit is refilled, you can only check the technical sticker. No external signs or year of purchase will give a 100% guarantee without visual confirmation. Always check this information before starting any work.
⚠️ Warning: Mixing different types of refrigerants (for example, adding R134a to a system designed for R600a) leads to irreversible damage to the compressor and an explosive situation in the case of isobutane.
How to determine the type of gas by nameplate
To accurately identify the working substance, you do not need to be a certified engineer. All the necessary information is contained on the factory markings, which manufacturers place in accessible places. Ignoring this information when attempting to repair it yourself may result in using the wrong equipment.
Look for a sticker with the logo Bosch and serial number on the body of the refrigerator compartment or on the back wall. It is there, among many numbers and letters, that technical parameters are indicated, including the type and weight of the refrigerant being charged. Typically, this information is highlighted in a separate column or line.
Pay attention to the following designations that may appear in the “Refrigerant” or “Kältemittel” field:
- 🧊 R600a — indicates isobutane, commonly found in modern energy-efficient models.
- ❄️ R134a — denotes tetrafluoroethane, typical for units manufactured in the 2000s and early 2010s.
- ⚠️ R12 — obsolete freon, found only in very old units, now banned for production.
In addition to the type of gas, its quantity in grams must be indicated on the nameplate. This figure is critically important for the master, since filling rate it must be observed to the nearest gram. Overfilling or underfilling of gas will disrupt the thermodynamic cycle of the refrigerator.
Correspondence table of models and standards refills
The amount of refrigerant varies depending on the volume of the chambers, the number of compressors and the design of the evaporator. You cannot be guided by the principle of “tuck it in by eye” or “until a characteristic sound”. Below is a reference table showing the range of standards for popular series.
| Series / Model | Refrigerant type | Filling rate (g) | Oil type |
|---|---|---|---|
| Bosch Serie 4 (NoFrost) | R600a | 50 - 65 g | POE (Synthetics) |
| Bosch KGN (Two-compressor) | R600a | 90 - 110 g (total) | POE / Mineral |
| Bosch Classic (Old models) | R134a | 120 - 140 g | PAG / POE |
| Bosch Inox Side-by-Side | R600a | 130 - 150 g | POE |
As can be seen from the table, modern models require significantly less gas due to improved thermal insulation and compressor efficiency. Using R600a allows you to reduce the pressure in the system, which reduces the load on the unit components.
It is important to note that the oil in the system also depends on the type of freon. For R134a and R600a synthetic oils (POE) are often used, which are hygroscopic, that is, they actively absorb moisture from the air. This makes the procedure for vacuuming the system mandatory.
Signs of a leak and the need to refill
Before thinking about what and how refrigerators are refilled, you need to make sure there is a leak. The sealed circuit does not require gas consumption in normal mode. If the refrigerant level has dropped, it means that the integrity of the tubes has been compromised.
The first and most obvious sign is an increase in temperature in the chambers when the compressor is running. The engine may hum constantly or turn on too often, trying to compensate for the lack of cold. However, similar symptoms also occur when the thermostat is malfunctioning.
More accurate signs indicating a loss of gas:
- 🌡️ Warm condenser — the side walls or rear grille remain cold, although the compressor is hot.
- 🧊 Lack of frost —on the evaporator inside the freezer does not have a uniform layer of frost, only individual sections or tubes are visible.
- 🔊 The sound of overflowing liquid —when the compressor stops, gurgling is heard, which indicates air or a mixture of gases has entered the circuit.
⚠️ Attention: If you find an oily stain under the refrigerator or on the back wall, this is almost 100% a sign of a leak. Oil leaves the system along with gas under pressure.
It is better to carry out diagnostics comprehensively. Visual inspection of the tubes, especially in solder areas and near door hinges, often helps to find micro-cracks. It is through them that the gas evaporates into the atmosphere for years until the pressure becomes critically low.
Why can’t you just add gas?
Adding gas without evacuating the system will result in air and moisture remaining in the circuit. The moisture will react with the oil, forming an acid that will corrode the compressor from the inside. The air will create an “air lock”, increase the condensation pressure and lead to overload of the motor.
Refilling technology and necessary equipment
The process of refilling a Bosch refrigerator is not just connecting a gas cylinder. This is a technological operation that requires adherence to a strict sequence of actions and the use of specialized tools. Violation of technology negates all efforts and can be dangerous.
First of all, it is necessary to find and eliminate the location of the leak. If you simply refill the system, the gas will come out again through the same hole. After soldering the damaged area, nitrogen pressure testing is carried out to check the tightness.
The main stages of professional refilling include:
- Removing residual old refrigerant and oil.
- Replacing the filter-drier (a mandatory procedure when depressurization).
- Deep evacuation of the system to remove moisture and air.
- Weighted refrigerant charge by weight.
For work with R600a special equipment with spark-proof elements is required, since a gas concentration in the air of more than 1.3% creates an explosive mixture. In a domestic environment, it is almost impossible to ensure such safety.
☑️ Checklist for preparing for refueling
The key point is the use of electronic scales. Filling “by eye” or by pressure (especially for isobutane) is unacceptable. The pressure in the system depends on the ambient temperature, and you cannot rely on a pressure gauge when filling R600a.
Safety and precautions
Working with refrigerants requires an understanding of the risks. Although modern freons are less toxic than their predecessors, they still pose a danger if mishandled. This is especially true for flammable gases used in Bosch equipment.
When working with isobutane the use of open flame and sparking tools near the refueling site is strictly prohibited. The room must be well ventilated to prevent the accumulation of gas in the event of an accidental release.
Basic safety rules:
- 🚫 None fire - soldering should only be done after complete removal of gas from the circuit and ventilation.
- 🧤 Protection of hands and eyes —liquid freon, when evaporated, causes severe frostbite of the skin.
- 🌬️ Ventilation —carry out work only in rooms with forced or natural draft.
⚠️ Attention: Never try to refuel the refrigerator unless you are sure there will be no sparking. Isobutane is heavier than air and accumulates in the lower part of the room, creating an invisible threat.
It is also worth remembering the chemical activity of oils. Synthetic oils used with new freons are aggressive to some types of rubber and plastics. Contact of such oil on skin or clothing may cause irritation.
Frequently asked questions (FAQ)
Is it possible to fill a Bosch refrigerator with freon from another brand?
Absolutely not. Each compressor and piping system is designed to handle a specific type of refrigerant and oil. Replacing R600a with R134a or vice versa will lead to compressor failure, since they have different operating pressures and lubrication requirements.
How often do you need to change freon in a refrigerator?
In a working refrigerator, freon does not change and is never consumed. It circulates in a closed loop for decades. If the gas disappears, it means that a hole has formed that needs to be found and soldered, and then the system must be refilled.
How much does it cost to refill a Bosch refrigerator?
The price depends on the region and the complexity of access to the system, but it consists of the cost of work, the technician’s visit and the cost of the refrigerant. Usually this is not the most expensive part of the repair, unless a compressor replacement is required.
Why does the refrigerator freeze worse after refueling?
This may indicate an error in the amount of gas filled (underfilling or overfilling), the presence of an air lock in the system or poor-quality evacuation, which is why moisture remains in the circuit, frozen in the capillary handset.