The situation when the refrigerator suddenly stops freezing, and the compressor hums without stopping, is familiar to many owners of household appliances. Most often, the reason for this behavior is the refrigerant leak gas that provides cooling to the chambers. An attempt to solve the problem yourself by simply “topping up” gas can lead to a breakdown of the compressor or even an explosion of the system if you do not follow the technology.
Before taking active steps, you must clearly understand: Refilling the refrigerator is not just adding gas, but a complex process of restoring the tightness of the circuit. If there is a hole in the system, freon will leak out again and again until you find and seal the leak. In this article we will analyze all the stages, from diagnostics to the final start-up, but remember that working with gas requires caution and special equipment.
Do not panic if you find that food has stopped freezing. Modern equipment is often equipped with protection systems, but they cannot compensate for the lack of working fluid in the system. Refrigerant circulates in a vicious circle, and its quantity is strictly regulated by the manufacturer. Any intervention requires accuracy and understanding of physical processes.
Leak diagnosis and equipment preparation
The first step should always be a thorough diagnosis. Just like that, “just in case,” the gas does not evaporate. If the refrigerator stops cooling, but the compressor is running, it means the pressure in the system has dropped. You will need to find the place where the depressurization occurred. This often happens in the evaporator (“crying” evaporator) or in the foamed part of the housing.
To find leaks, technicians use leak detectors or the soap suds method. At home, you can use a solution of laundry soap. If you hear a characteristic hissing sound or see inflating bubbles, the location has been found. However, leaks are often microscopic and only appear under pressure.
To carry out the work, you will need a specific set of tools, without which the process is impossible. It is important to prepare everything in advance so as not to interrupt the process halfway.
- 🛠️ Vacuum pump —necessary to remove moisture and air from the system before refueling.
- 🔧 Gauge station —allows you to control the pressure during evacuation and refueling.
- 🔥 Burner (gas or oxygen) and solder - for sealing tubes and eliminating leaks.
- ⚖️ Electronic scales - for accurate weighing of the amount of refilled freon.
⚠️ Attention: Freon, being under pressure, if released abruptly, it can cause frostbite to the skin. Carry out all work in a well-ventilated area and use protective gloves.
Choosing the type of refrigerant for your refrigerator
It is critically important to use exactly the type of gas that is indicated on the technical tag of your unit. Most often, household refrigerators use R134a or R600a (isobutane). They cannot be confused, since they have different chemical formulas, pressures and, most importantly, the type of oil for the compressor.
If R134a is poured into a refrigerator running on R600a, the compressor will quickly fail due to incompatibility of the oils. Conversely, R600a is a flammable gas and its use in a system not designed for it may result in an explosion. Therefore, carefully study the labeling.
The following table helps to distinguish the main types of refrigerants and their features:
| Freon type | Chemical name | Features | Flammability |
|---|---|---|---|
| R134a | Tetrafluoroethane | High operating pressure, non-flammable | No |
| R600a | Isobutane | Low pressure, high efficiency | Yes (explosive) |
| R12 | Dichlorodifluoromethane | Outdated, prohibited for use | No |
The system must be refilled strictly by weight. The refrigerator label always indicates the exact number of grams (for example, 130 g). The use of cylinders with a measuring scale or scales is mandatory. Refilling It is just as dangerous as underfilling: it increases pressure and ruptures the tubes or damages the compressor.
The process of eliminating leaks and soldering tubes
Once the leak has been found, it is necessary to remove the remaining old gas. If there is freon left in the system, it cannot simply be released into the atmosphere (this is harmful to the environment), but in domestic conditions it is often released through a piercer. Next comes the most important stage - soldering.
The refrigerator tubes are made of copper or steel. Silver solder or special copper-phosphorus wire is used for connection. The soldering area must be cleaned to a shine, heated with a torch and solder applied. It is important not to overheat the tube, otherwise it will burn out, creating a new hole next to the repaired one.
If the leak occurs in the foamed part (the evaporator inside the wall), the repair becomes more complicated. You have to open the thermal insulation, cut out a piece of the evaporator and weld in a new piece (“fin”). This requires the skills of a welder.
What to do if the tube burns out?
If the tube burns out over time, it is better to replace the entire section. Spot soldering on thinned metal is a temporary solution that may not withstand pressure after a month.
After soldering, the system must be checked for leaks under nitrogen pressure. This is a professional stage that “home craftsmen” often skip, and in vain. Supplying nitrogen under a pressure of 10-15 atmospheres will immediately show whether the seam is holding.
Evacuating the cooling system
Many people mistakenly believe that after soldering you can immediately release freon. This is a grave mistake. There is still air in the system that contains moisture. When the refrigerator is operating, moisture will freeze in the capillary tube, forming an ice plug, and circulation will stop.
Used vacuum pumpto remove air and moisture. It is connected to the service connection via a pressure gauge station. The pump turns on for 15-30 minutes. The pressure in the system should drop to a deep vacuum (the pressure gauge needle will go negative to the limit).
- 🌪️ Connect the pump to the blue hose of the pressure gauge station.
- ⏱️ Open the low pressure valve and turn on pump.
- 📉 Follow the arrow - it should drop below zero.
- ⏳ Leave the pump running for at least 20 minutes to evaporate the moisture.
⚠️ Attention: Before turning off the pump, be sure to close the valve at the station so that oil from the pump or air is not sucked back into system.
The vacuum process also allows you to finally verify the tightness of the assembly. If, after turning off the pump, the pressure gauge needle begins to creep up, it means that a microscopic gap remains somewhere, and soldering must be repeated.
☑️ Check before vacuuming
Technology for filling freon by weight
When the vacuum is created, the moment of filling comes. The freon cylinder is installed on the scales. The hose from the cylinder (preferably yellow) is connected to the central fitting of the pressure gauge station. Before connecting to the station, you need to bleed a little gas from the hose to expel the air.
Open the valve on the cylinder (the cylinder should be upside down if it is R134a, or bottom down if it is R600a - read the instructions on the cylinder!). We open the valve at the station. Gas begins to enter the system. At this stage, the compressor cannot be turned on!
Refilling is carried out until a certain pressure is reached or, more correctly, until the desired weight is reached. The scale will show how many grams came out of the cylinder. As soon as the scale arrow shows that exactly as many grams have been consumed as indicated in the passport (for example, 130 g), the gas supply is turned off.
Procedure for refueling:1. Open the valve on the cylinder.
2. Open the valve at the station.
3. Keep an eye on the scales.
4. Close the valve at the station.
5. Close the valve on the cylinder.
After this, you need to quickly, before the gas goes back into the hose, pinch the service tube with pliers and solder it. Only after sealing can you turn on the compressor to check operation.
Checking the operation and balancing of the system
After starting the compressor, it is necessary to control the process of reaching the mode. In the first minutes, the pressure on the pressure gauge will jump. After 10-15 minutes it will stabilize. For R134a, the operating suction pressure is usually about 0.05-0.1 MPa, but the exact numbers depend on the temperature in the chamber.
Inspect the condenser (grid at the back). It should heat evenly from top to bottom. If only the top part heats up and the bottom is cold, there may be an air lock or blockage left in the system. If the condenser is hot, but there is no cold in the chamber, check whether the fan is working (if there is one) and whether the evaporator is clogged with ice.
The final step is to check the temperature. After 2-3 hours of operation, the temperature in the freezer should be below -18°C, and in the refrigerator - about +4...+5°C. If the indicators are normal, the repair can be considered successful.
What to do if after refueling the refrigerator does not freeze?
If after refueling the cold does not appear, there may be several reasons: a clogged capillary tube (purging with nitrogen is required), a malfunction of the compressor (it does not create the required pressure) or an error in the amount of freon charged. Also check whether the thermostat is seated tightly.
Is it possible to use freon from a car air conditioner?
Absolutely not. Car air conditioners often use R12 freon or mixtures, as well as specific oils. Using the wrong refrigerant will destroy the refrigerator compressor.
How often do you need to change freon in a working refrigerator?
In a working, sealed refrigerator, freon circulates forever and never runs out. If the gas has disappeared somewhere, it means there is a hole in the system that needs to be found and eliminated. Simply “adding” gas without repair is a temporary measure for a couple of weeks.
Is it dangerous to breathe freon vapors?
Yes, it is dangerous. Freon displaces oxygen, which can lead to suffocation. In addition, upon contact with an open flame, some types of freon disintegrate into phosgene, a chemical warfare agent. Work only with the window open.