A decrease in cooling efficiency or complete loss of cold in the refrigerator LG often indicates a refrigerant leak. Many owners immediately think about refueling themselves, wanting to save on calling a technician. However, this process is technically complex and requires not only special equipment, but also a deep understanding of the operating principles of compressor-condenser group.
Before taking active steps, you need to be aware of the risks. Incorrect refueling or using the wrong type of freon can lead to compressor failure. In this article we will analyze the theoretical aspects and practical steps that professionals take so that you can assess your strengths and the need to purchase an expensive tool.
Modern refrigerators LG, especially models with the system No Frost and inverter compressors are complex units. A leak in the circuit is not just a loss of gas, it is the entry of moisture and air into the system, which is a critical factor in the failure. Therefore, the “just add gas” approach here absolutely does not work and can finish off a motor that is still working.
Diagnostics of a leak and selection of refrigerant
The first step is always to find the location of the leak. If you simply connect a freon bottle to a system where there is a hole, the gas will quickly escape and the compressor will run idle. To search, use a soap solution or an electronic leak detector. Carefully inspect everything connecting tubes, especially in the soldering areas and near the evaporator.
Particular attention should be paid to the foamed parts of the case. If the leak occurs in a foamed circuit (inside the wall of the refrigerator), then simple refilling will not be enough. It will require either the installation of an external evaporator ("crying" one on the rear wall), which changes the aesthetics of the unit, or a complex repair involving ripping open the casing. It is impossible to visually determine the type of refrigerant; this information can only be found on the technical sticker.
Refrigerators LG can operate on different types of refrigerants, and mixing them is unacceptable. The most common are R134a (environmentally safe, but requiring synthetic oil) and R600a (isobutane). The latter is a flammable gas, which imposes additional restrictions on the work.
⚠️ Attention: The use of freon R600a requires special care due to its explosion hazard. All work must be carried out in a well-ventilated area away from open sources of fire and sparking electrical appliances.
The type of refrigerant used and its exact amount (in grams) are indicated on the nameplate, usually located inside the refrigerator compartment or on the back wall. Ignoring this data will lead to incorrect operation system failure. Undercharging will cause overheating of the compressor, and overcharging will cause water hammer and destruction of the valves.
If you find that the tube is bitten or broken off, it must be carefully cut and cleaned. The fracture site is often the entry point for moisture. Before you think about gas, you need to ensure complete tightness all connections. Any microcrack will negate all restoration efforts.
Necessary tools and equipment
Refilling the refrigerator is not a job with a wrench and a screwdriver. You will need a specialized set of tools, the cost of which may exceed the cost of calling a specialist. The basic minimum includes a vacuum pump, a pressure gauge station (manifold) and a freon cylinder. Without a vacuum pump, it is impossible to do a quality job.
A vacuum pump is necessary to remove air and, most importantly, moisture vapor from the system. Moisture at low temperatures turns into ice and clogs the capillary tube, causing the “ice plug” effect. The pressure manifold allows you to control the pressure in the circuit. For different freons, different scales and colors of hoses are used: blue - for low pressure, red - for high pressure.
You will also need:
- 🔧 Burner (gas or oxygen) and solder for soldering copper tubes.
- 🧪 Pipe cutter and a roller (if replacement of sections of the main line is required).
- ⚖️ Electronic scales high precision for gas dosing.
- 🔌 Filter drier (necessarily changes whenever the circuit is opened).
Filter drier is a consumable element that adsorbs moisture and oil breakdown products. When the system is opened, the old filter instantly absorbs moisture from the air and ceases to perform its functions. Installing a new filter is strictly necessaryotherwise the system will quickly become dirty.
A filling hose is used to connect the freon cylinder. Using homemade devices or hoses from other systems (for example, car air conditioners without adapters) can lead to depressurization injuries.
The issue of soldering deserves special attention. Copper tubes in refrigerators LG have thin walls. Overheating can lead to burning of the metal or the formation of oxides inside the tube, which then clog capillary. Therefore, the use of flux and the correct solder (containing silver or phosphorus) is critical for the durability of the repair.
System preparation: soldering and vacuuming
The preparation process begins with dismantling the old filter-drier and installing a new one. The filter is soldered into the line gap on the high pressure side (after the condenser, before the capillary). Soldering must be done quickly so as not to overheat the filter, otherwise its properties will be lost. Heating the filter housing with an open flame is prohibited.
After replacing the filter and restoring the integrity of the circuit (if there were cuts or replacement of tubes), it is necessary to check the system for leaks. To do this, the circuit is often “pressured” with nitrogen. If the pressure remains stable for several hours, you can proceed to evacuation. This stage takes the most time.
Evacuation is carried out as follows:
- Connect the vacuum pump to the service port (or soldered fitting).
- Turn on the pump and watch the pressure gauge arrow.
- The arrow should go to "minus" (usually up to -1 atm or 760 mm Hg).
- The pump should run for at least 30-40 minutes, and for systems with R600a it is better to increase the time to an hour.
The purpose of vacuuming is to reduce the boiling point of water inside the system. In a deep vacuum, water boils and evaporates even at room temperature, after which it is pumped out. Neglecting this stage is the main reason for repeated breakdowns. The remaining moisture will freeze in capillary tube and block the circulation of freon.
⚠️ Attention: Never turn on the compressor if a deep vacuum has been created in the system, without first checking or filling with a small amount of refrigerant. Dry operation in a vacuum can damage the windings or mechanics of the motor.
After the pump has finished operating, you need to close the valve on the collector and only then turn off the pump. If done the other way around, oil from the pump may be drawn back into the refrigerator system. This phenomenon is called reverse popping and requires flushing the system.
☑️ Checklist for preparing for refueling
The process of filling the refrigerator with freon
The most crucial moment is the introduction of refrigerant. It is important to understand that refilling is carried out strictly according to the weight indicated on the refrigerator nameplate LG. Filling by eye or by pressure (especially for R134a and R600a) is a serious mistake. The pressure in the system depends on the ambient temperature and is not an accurate indicator of the amount of the substance.
For accurate dosage, the freon cylinder is placed on an electronic scale. Before refueling, the scales are tared (zeroed). The valve on the cylinder and the low pressure valve on the manifold (blue) open. Freon begins to enter the system. At this moment, the compressor is usually turned off, and gas fills the circuit under its own pressure.
Table of typical charging parameters for different models:
| Refrigerant type | Average charging weight (g) | Suction pressure (bar)* | Features |
|---|---|---|---|
| R134a | 60 - 140 | 0.6 - 0.8 | Non-flammable, requires synthetic oil |
| R600a | 30 - 60 | 0.4 - 0.6 | Explosive, low dose, mineral oil |
| R12 | 100 - 180 | 1.0 - 1.2 | Outdated, prohibited for production |
*The pressure is indicated approximately for an ambient temperature of +25°C and a working compressor.
After the initial filling (usually 60-70% of the norm), you can start the compressor. Further topping up is done in small portions with the engine running. Freon must enter the system in a gaseous state to prevent water hammer. If the cylinder is turned over, liquid will flow into the system, which can instantly destroy the compressor valves.
Control your weight on electronic scales in real time. As soon as the arrow shows the desired value, close the valve on the cylinder, then on the manifold. After this, the service pipe is sealed or clamped (clamps are often used for R600a, since soldering with an open flame is dangerous in the presence of gas).
Why can’t you fill R600a by pressure?
Isobutane (R600a) has a very low operating pressure. A small error in the gauge reading (due to calibration or temperature, for example) will result in a huge error in grams. Since the filling dose is only 50 grams, an error of 10 grams is already a 20% deviation, which is critical for the operation of the system.
Operation control and typical errors
After completing the filling, you must let the refrigerator run for at least an hour. At this time, visual and tactile control is carried out. The condenser (grid at the back or side walls) should be heated evenly over the entire area. There should be no cold areas indicating blockage or excessively hot areas.
A typical mistake is underfilling freon. In this case, the compressor will work continuously, trying to gain temperature, but the cold will not reach the required values. Overheating winding of the compressor in this mode is inevitable. The other extreme is overflow. Liquid freon may not have time to evaporate and enter the compressor suction, causing knocking and vibration.
Symptoms of proper operation:
- ❄️ Uniform cooling of both chambers.
- 🔇 Quiet, smooth operation of the compressor without knocking or gurgling.
- 🌡️ The temperature at the outlet of the evaporator is normal (usually about -15..-18°C in the freezer).
Another common mistake is poor soldering. Microcracks can appear only after a heating-cooling cycle. Therefore, after repair, it is recommended to leave the refrigerator turned on for a day without loading food to make sure that the temperature is stable and there are no leaks.
⚠️ Attention: If after refueling the compressor works, but there is no cold, and the pressure on the pressure gauge “jumps” or is in a vacuum, this is a sign of a clogged capillary tube or filter. The system needs to be purged with nitrogen under pressure and the filter replaced again.
Do not forget that modern refrigerators LG are equipped with complex electronics. If you see error codes on the display, this may be due not only to the gas, but also to a malfunction of the temperature sensors, which may have been damaged during soldering. Always check the electrical part before starting gas work.
When self-repair is impossible
Despite the availability of instructions and tools, there are situations when you should not undertake repairs yourself. If you do not have experience working with open fire and copper pipes, there is a high risk of damaging expensive evaporator or burning the wall of the refrigerator. Restoring a foamed evaporator at home is almost impossible without losing aesthetics and efficiency.
It is also worth thinking about calling a specialist if the compressor itself has failed. Replacing the motor requires not only soldering, but also often reflashing the control board (for inverter models LG). Independently replacing a conventional compressor with an inverter one or vice versa is impossible without replacing the board and reconfiguring the control system.
Factors requiring professional intervention:
- 🔥 Leak in the foamed part of the housing (requires opening or installation of an attached evaporator).
- 🔌 Failure of the inverter compressor or control board.
- 🌬️ Large amounts of moisture or oil entering the system (professional flushing required).
Remember that a professional technician has access to original spare parts and manufacturer specifications. He is also responsible for the work performed. Self-repair will void your warranty, if it was still valid, and may lead to additional expenses in case of failure.
Is it possible to refill a refrigerator without scales?
Theoretically, experienced craftsmen can be guided by the current consumption of the compressor and the temperature of the tubes. However, this method is not suitable for a beginner. Without scales, you are guaranteed to upset the balancing of the system, which will lead to either inefficient cooling or compressor failure.
Frequently asked questions (FAQ)
Is it possible to fill a refrigerator with R12 freon instead of R134a?
No, this is strictly prohibited. Freons have different chemical properties and require different types of oils. R12 runs on mineral oil, while R134a runs on synthetic (polyester) oil. Mixing or replacing will lead to oil curdling, acid formation and rapid compressor failure. Use only the type of refrigerant specified by the manufacturer.
Why does the refrigerator freeze after refilling, but then stops?
Most likely, there is moisture left in the system, which has frozen in the capillary tube, forming an ice plug. After some time of operation, the ice may melt and the refrigerator will start working again, then the cycle will repeat. There is only one solution: a complete refill with high-quality vacuuming and replacement of the filter-drier.
How much does it cost to refill an LG refrigerator with freon from a specialist?
The price depends on the region, the type of compressor (regular or inverter) and the complexity of access to the system. The price usually includes labor, freon, filter drier and travel. The exact amount can only be found out after diagnosis, since if there is a leak, a search for the place of damage and soldering will be required, which is paid separately.
Is freon from a refrigerator dangerous for humans?
Modern freons (R134a, R600a) in small quantities contained in a household refrigerator are not toxic during short-term inhalation. However, R600a is explosive in concentrations with air. R134a may release phosgene when heated. Therefore, any work with gas should be carried out in a ventilated area and avoid open fire.