Depressurization of the refrigeration circuit is a critical malfunction in which the refrigerant (freon) leaves the closed piping system, disrupting the cooling cycle. For the user, this event often looks like a sudden stop in the operation of the unit: the motor-compressor hums, but there is no cold, or the temperature in the chambers ceases to drop to the set values. Understanding the physical processes occurring at this moment is necessary for correct diagnosis and prevention of further breakdowns of expensive components.
In normal conditions, the pressure in the circuit is strictly regulated, and the refrigerant circulates, changing its state of aggregation. If this happens depressurization of the system, the pressure drops and the compressor begins to work in emergency mode, trying to compensate for the losses. Ignoring the primary symptoms can lead to combustion of the compressor motor, as it overheats due to lack of cooling by the freon flow. That is why it is important to notice changes in the operation of household appliances in a timely manner.
Modern models, be it Indesit, Atlant or LG, are equipped with protective relays, but they do not always operate instantly. A leak can be microscopic and last for months, gradually reducing performance, or it can happen instantly due to mechanical failure. In both cases, the result is the same - a violation of heat transfer. Let's look in detail at why this happens and what the owner should do.
Main signs of a circuit leak
The first and most obvious symptom for the owner is a change in temperature. The food in the main chamber begins to thaw, and ice forms in the freezer or, conversely, the ice completely disappears when the compressor is running. However, you cannot rely only on a thermometer, since similar signs may indicate a malfunction of the thermostat or problems with the door seal.
A more accurate indicator is the behavior of the motor-compressor. If freon leaks, it can work continuously without turning off, or it can turn on for short periods of time with a characteristic click and turn off immediately. This indicates that thermal protection relay the engine is shutting down due to overheating. The compressor housing may be hot, while the condenser (grid at the back) remains cold or barely warm.
Visual inspection can also provide important clues. If you have a model with a No Frostsystem, pay attention to the evaporator: if there is a lack of freon, it may become overgrown with an uneven “fur coat” or have “bald” areas. In older models with a weeping evaporator, swelling of the side walls or the appearance of oily spots on the floor under the refrigerator may indicate a break in the pipes.
- 🚫 The compressor works non-stop or often clicks, but does not start fully.
- 🌡️ The temperature in the chambers does not drop below +10...+15 degrees even at minimum settings.
- 💧 The appearance of oily spots under the refrigerator or on the back wall.
- ❄️ Uneven formation of frost on the evaporator or its complete absence.
⚠️ Attention: If you hear a hissing sound when you turn on the refrigerator, immediately disconnect the device from the network. This is a direct sign of an active gas leak under pressure.
Mechanical damage as a cause of leakage
The most common cause of depressurization is physical damage to the pipelines, which the user causes independently. Aluminum evaporator tubes in modern refrigerators are extremely thin and vulnerable. A careless movement with a knife when trying to pick out ice or too sudden a movement during defrosting is enough to break through the canal wall.
Inaccurate transportation also includes mechanical damage. If the refrigerator was transported lying down without following the rules, or during a skid the condenser pipes located at the rear were strongly pulled, a crack could occur. In places where copper tubes are bent, the metal experiences stress, and over time, microcracks can form there, which turn into fistulas under pressure.
Corrosion is another enemy of tightness, especially in models where the steel circuit elements do not have sufficient anti-corrosion protection. In conditions of high humidity or upon contact with aggressive media, the metal becomes thinner. Hidden corrosion often develops under thermal insulation, and it is detected already when the freon has completely evaporated.
Why can’t you repair pipes by cold welding?
Cold welding and sealants do not withstand cyclic changes in pressure and temperature inside the circuit. Compressor vibration will quickly destroy such a patch, and the chemical components of the sealant can clog the capillary tube, making repairs impossible without replacing the entire assembly.
Manufacturing defects and natural wear and tear of materials
Do not discount manufacturing defects that may appear after years of operation. Poor-quality soldering of connections, microscopic holes in the metal of the tubes, or the use of low-quality metal - all this leads to premature depressurization. This is especially common in budget models, where manufacturers save on materials.
Natural wear and tear also plays a role. Cycles of expansion and contraction of metal during heating and cooling over 10-15 years lead to metal fatigue. In solder joints, where different metals (copper and steel, copper and aluminum) are connected, galvanic couples occur, which promote electrochemical corrosion. This is a complex physical and chemical process that is almost impossible to stop without completely replacing the circuit.
In models with the system No Frost problems can be caused by the defrost heater. If the heating element burns out or shorts to the evaporator body, it can locally melt aluminum tubes located in the immediate vicinity. This is a classic malfunction that requires professional intervention and replacement of the evaporator.
Diagnostics: how to find a freon leak
Finding a leak is a complex technical process, which in 90% of cases is impossible at home without special tools. Visually finding a microscopic hole in the foamed part of the body or in hidden coils is almost impossible. Experts use special methods to localize the problem with high accuracy.
One of the most common methods is the use of a leak detector. This is an electronic device that reacts to the presence of freon molecules in the air. The technician moves the probe along the tubes, and when approaching the leak, the device emits a sound signal. However, this method is effective only if there is residual pressure in the system.
If there is no pressure, the circuit is filled with nitrogen under high pressure (pressure testing) and immersed in water or lubricated with a soap solution. Air bubbles will indicate the location of the rupture. For hidden leaks in the foamed layer (inside the walls of the refrigerator), a color flaw detection method is used with the addition of a phosphor to the oil or gas, which glows under ultraviolet light.
| Search method | Operation principle | Efficiency | Required equipment |
|---|---|---|---|
| Soap solution | Visualization of air bubbles | High (for open places) | Spray bottle, water, soap |
| Electronic leak detector | Sensor response to gas | Average (depending on pressure) | Leak detector (helium/freon) |
| Nitrogen pressure testing | Fall control pressure | High (confirms the fact) | Nitrogen cylinder, reducer, pressure gauge |
| Ultraviolet | Luminescent phosphor | High (for complex cases) | UV lamp, fluorescent additive |
⚠️ Attention: Never try to look for a leak with an open flame (lighter). Freon, when in contact with fire, releases phosgene, a dangerous poisonous gas.
Technology for restoring system tightness
Repairing a depressurized refrigerator is not just “filling up the hole.” This is a set of works to restore the integrity of the circuit, evacuation and charging with refrigerant. If the leak occurs in an accessible place (for example, a locking connection or an open condenser tube), the technician can install a coupling or solder the damaged area with a torch.
The situation becomes more complicated if the breakdown occurs in the foamed layer (inside the housing wall). In this case, you cannot simply solder the tube, since access to it is blocked by polyurethane foam. There are two ways: opening the wall (which spoils the appearance and requires complex waterproofing) or cutting off the damaged area and installing a new external condenser or evaporator.
After eliminating the physical leak, a vacuum procedure is required. All air and, most importantly, moisture must be removed from the system. Moisture in the system freezes in the capillary tube, forming an ice plug that blocks the circulation of freon. For this, a vacuum pump is used, which runs from 20 to 40 minutes.
☑️ Stages of quality repair
Final stage - refueling refrigerant. The type of freon (R134a, R600a, R407) and its quantity are strictly regulated by the manufacturer and are indicated on a tag on the back of the refrigerator. Refilling "by eye" is unacceptable: an excess of freon will lead to a liquid shock to the compressor, and a deficiency will lead to ineffective operation and overheating.
The cost of repairs and the feasibility of restoration
Owners often wonder: is it worth repairing a refrigerator when depressurization? The answer depends on the location of the leak and the age of the equipment. If an open tube is broken or a connection fails, repairs will be relatively inexpensive. However, if the compressor burns out due to dry operation or a leak occurs in the foamed layer, the cost of work can reach 50-70% of the price of a new refrigerator.
The price is influenced by the cost of materials (copper, freon, compressor) and labor intensity. Refilling with freon R600a (isobutane) requires special care, since this gas is explosive in concentration, which increases the cost of work due to the need to comply with strict safety standards.
If your refrigerator is more than 10-12 years old, and you need to replace the compressor plus repair a leak in the housing, it is more economically feasible to consider purchasing new equipment. Older models are less energy efficient, and the investment in their repair may not pay off in the foreseeable future.
⚠️ Please note: Prices for services and parts may vary. Before starting work, always request a detailed estimate from the specialist, including the cost of travel and diagnostics.
Is it possible to refill the refrigerator yourself?
Theoretically, it is possible if you have the equipment (scales, pressure gauge station, vacuum pump) and skills. However, without eliminating the cause of the leak, refilling will only give a temporary effect for 2-4 weeks, after which the gas will escape again.
Prevention and operating rules
To avoid depressurization, you must follow the operating rules. The main thing is to never use sharp objects to remove ice. If an ice crust has formed, allow the refrigerator to thaw naturally or use special defrosting sprays that are safe for plastic and metal.
When cleaning, do not move the refrigerator away sharply, grabbing the condenser tubes from behind. They are easily deformed. It is also important to keep the rear grille clean: a layer of dust several millimeters thick impairs heat transfer, forcing the compressor to work longer and harder, which increases the pressure in the system and the risk of rupture of weak points.
Regularly check the condition of the door seal. If it does not fit tightly, warm, moist air enters the chamber, which leads to increased ice formation on the evaporator. The user's attempts to mechanically remove this excess ice most often lead to punctures.
How long does the refrigerator work after depressurization?
If the leak is small, the refrigerator may run “idle” for several weeks or even months, trying to gain temperature. However, the compressor is overloaded at this time, which significantly reduces its service life. If the hole is large, the cold will disappear in a few hours or days.
Is it dangerous to breathe freon vapors during a leak?
In household quantities, modern freons (R134a, R600a) are low-toxic, but displace oxygen. In a small, unventilated area (such as a closet), a large leak can cause suffocation. In addition, R600a is explosive. Therefore, if a leak is suspected, the room needs to be ventilated.
Why does the refrigerator not cool after refilling freon?
There may be several reasons: moisture remains in the system (an ice plug has formed), the dose of freon has been incorrectly selected, the capillary filter is clogged, or the second, hidden leak has not been eliminated. A compressor that had been operating in emergency mode for a long time could also fail.
Is it possible to use a sealant to eliminate a leak?
There are special sealants for car air conditioners, but their use in household refrigerators is categorically not recommended by specialists. The sealant can clog the thinnest capillary tube or filter drier, which will require a complete flushing of the system or replacement of expensive components.