Detection of deformation of the body of a household refrigerator is always an alarming signal that requires the immediate attention of the owner. When the rear wall bulges, this indicates serious malfunctions in the cooling system or mechanical damage that cannot be ignored. A visual change in the geometry of the metal sheet is often accompanied by a loss of cold, the hum of the compressor, or a complete failure of the equipment to work.
Many users mistakenly believe that the bulge on the back panel is only a cosmetic defect, but in 90% of cases this hides critical pressure inside the system or the destruction of the thermal insulation layer. Ignoring the problem in the early stages can lead to expensive repairs or the complete impossibility of restoring the unit. Understanding the physics of the process will help you quickly diagnose a malfunction and make the right decision to call a technician.
In this article we will analyze in detail all possible scenarios leading to deformation of the housing, from a banal blockage to complex chemical reactions inside the structure. You have to find out why this happens swelling of thermal insulation and how to distinguish it from the consequences of high refrigerant pressure. Competent diagnostics will save your money and time.
Mechanical pressure of the refrigerant and compressor operation
One of the most common causes of swelling of the rear wall is a violation of the circulation of the refrigerant in the system. If compressor continues to pump freon, but the gas cannot circulate freely through the tubes due to blockage, the pressure in the circuit increases sharply. In modern models with foamed evaporators, the thin sheet of metal covering the insulation is the weakest link and begins to bend outward under the influence of force.
Often this effect is observed when the thermostat or electronic control module fails. The unit does not receive a signal to stop and works non-stop, trying to cover a non-existent volume of space. Constant overload leads not only to deformation of the housing, but also to overheating of the motor windings, which can lead to its combustion.
It is important to understand that pressure can create not only gas, but also liquid. If moisture gets into the system, it can freeze in the narrow area of the capillary tube, creating an ice plug. In this case, the compressor will pump freon to a dead end until the pressure becomes sufficient to deform the thin-walled structural elements.
- ❄️ Blockage of the capillary tube with oxidation products or dirt.
- 🔥 Overheating of the compressor due to the lack of pauses in operation.
- 💨 Air or moisture entering the circuit during unqualified repairs.
- 📉 Malfunction of temperature sensors, recording false readings.
⚠️ Attention: If you hear a characteristic hissing or whistling when you try to turn on a refrigerator with a swollen wall, immediately unplug the device. This may indicate an imminent rupture of the pipeline and the release of the entire volume of freon.
The situation is aggravated by the fact that modern refrigerators often have a hidden cooling system, where the pipelines are located behind the back panel inside polyurethane foam. The pressure in a closed volume acts over a large area, which causes visible swelling. Repair in such cases requires opening the foamed partwhich is a complex technological procedure.
Destruction of the thermal insulation layer and chemical reactions
The second most common cause of deformation is physico-chemical change in the properties of insulation. Polyurethane foam is used as thermal insulation in refrigerators, which is saturated with gas during production. Over time, under the influence of moisture, temperature changes or manufacturing defects, processes can begin in the structure of the foam, leading to the release of additional gases.
These gases have no outlet to the outside and begin to expand the structure from the inside. Unlike freon pressure, this process occurs more slowly, but is constant. The wall may swell uniformly or with local bubbles. This is often accompanied by the appearance of a specific odor or a change in the color of the plastic inside the chamber.
Models that have stood in an unheated room for a long time or were delivered in violation of transportation rules are especially susceptible to this phenomenon. Moisture that gets into the insulation expands when it freezes, and when it thaws it turns into steam, creating excess pressure in the cells of the polyurethane foam.
Is it possible to stop the destruction of the foam?
It is almost impossible to stop the chemical reaction inside the foamed space. The only way is to completely remove the old insulation and foam it again, which is not economically feasible for older models.
If the swelling is caused by the insulation, then the efficiency of the refrigerator can be maintained for a long time. However, the thermal conductivity of the damaged layer deteriorates, and the compressor has to work harder to maintain the set temperature. This creates a vicious circle that accelerates the wear of equipment.
The influence of corrosion and microcracks on the geometry of the body
Metal corrosion is a silent destroyer that often goes unnoticed until the moment of critical deformation. The rear wall of the refrigerator is constantly exposed to condensation, which flows down the condenser tubes. If the protective coating is broken, the oxidation process begins, the metal becomes thinner and loses its rigidity.
Under the influence of even slight internal pressure or mechanical stress, weakened areas begin to bulge. Microcracks in welds or soldering areas can also become points of deformation. Moisture penetrating through these defects accelerates the corrosion of internal elements.
Particular attention should be paid to models with aluminum evaporators, which are prone to pitting corrosion (“fistulas”). Although the evaporator itself is located inside, corrosion products and changes in pressure in the system can indirectly affect the condition of the rear panel. In older models, rust could eat through the metal, breaking the seal.
| Type of damage | Visual sign | Consequences | Difficulty of repair |
|---|---|---|---|
| Corrosion metal | Red spots, swelling of paint | Loss of tightness | High (sheet replacement) |
| Destruction of foam | Uniform swelling, bumps | Loss of cold, excessive energy consumption | Critical (unprofitable) |
| Freon pressure | Local swelling of the tubes | Risk of system rupture | Medium (search for blockages) |
| Mechanical shock | Dent or outward bending | Violation of door geometry | Low (straightening) |
To prevent corrosion, it is recommended to regularly check the condition of the drainage holes and condensate collection trays. Stagnation of water near metal parts of the body is the main enemy of the longevity of your refrigerator. Timely cleaning will extend the life of the unit.
Diagnostics: how to determine the exact cause of swelling
Before starting repairs, it is necessary to accurately determine the cause of the deformation. Primary diagnosis is carried out visually and auditorily. Turn on the refrigerator and listen to the compressor. If it works non-stop, but there is no cold, this is a sign freon leak or blockage of the system.
Inspect the place of swelling. If the deformation is located strictly above the foamed evaporator (usually the side or rear wall inside the chamber, but also affects the appearance), most likely the problem is a refrigerant leak from a hidden circuit. Freon, escaping under pressure into the polyurethane foam, expands it.
Use a soap solution to check the external connections. Apply it to the tubes at the back of the refrigerator. The appearance of bubbles will indicate the location of the leak. However, if the wall itself is swollen, but the tubes are intact, the problem lies deeper. In such cases, you cannot do without professional equipment.
☑️ Primary diagnostics of the refrigerator
It is also worth checking the integrity of the internal plastic lining. Cracks in the plastic inside the chamber are often a continuation of a thermal insulation problem. If the plastic bursts, it means that the pressure inside the insulation layer is really high. This confirms the theory about chemical processes or the release of gas from the cooling system.
Is it possible to eliminate bloating yourself
Many owners try to solve the problem cosmetically, trying to straighten the wall or drill a hole to relieve pressure. It is strictly forbidden to drill the back wall of the refrigerator without releasing the pressure and evacuating the system! This can lead to ignition of the oil in the compressor upon contact with air or poisoning freon combustion products.
If the swelling is caused by corrosion of the outer sheet, you can try to replace it. To do this, the old panel is carefully removed, the edges are cleaned, and a new sheet of metal is installed. However, this will only solve the external problem, without eliminating the cause if it lies inside.
In the case of polyurethane foam, independent repair is almost impossible. It requires complete removal of the back cover, cutting out the old foam, finding and eliminating leaks in the evaporator, and only then blowing in new insulation. This is a labor-intensive process that requires special equipment and skills.
⚠️ Attention: Freon, used in refrigerators, is heavier than air and has no odor. When there is a leak, it accumulates at the bottom, displacing oxygen. Carry out repair work only in a well-ventilated area.
If you do not have the skills to work with refrigeration equipment, it is better to limit yourself to an external assessment of the condition. Attempts to “treat” bloating with heat or mechanical impact can lead to complete failure of the system. Savings on calling a technician can result in the purchase of a new refrigerator.
Prevention and proper care of equipment
To avoid problems with case deformation, you must follow the operating rules. Do not place the refrigerator close to the wall; provide a gap for ventilation of at least 10 cm. Overheating of the rear accelerates the aging of materials and can contribute to bloating.
Regular defrosting (for No Frost models - preventative washing) helps control the condition of the internal surfaces. Make sure that food does not touch the back wall inside the chamber, as this can lead to local freezing and damage to the plastic.
Be careful when transporting or moving the refrigerator. Impacts to the back wall can damage not only the metal, but also disrupt the structure of the thermal insulation, which over time will lead to its peeling and swelling. A careful attitude will extend the life of the equipment.
When you need to call a specialist
A call to a specialist is required if the swelling is accompanied by a loss of cold or a constant hum of the compressor. A professional will be able to accurately determine the location of the leak using a leak detector and assess the feasibility of repair. In some cases, it is easier and cheaper to purchase a new unit.
The technician will also be able to safely bleed off any remaining refrigerant and evacuate the system before refilling. It is impossible to carry out these operations on your own due to the lack of a vacuum pump and a pressure gauge station.
Do not delay repairs if you notice progression of deformation. Over time, the area of the swelling will increase, which can lead to rupture of the internal tubes and oil contamination of the entire internal cavity of the refrigerator, which will make its restoration impossible.
Is it dangerous to use a refrigerator with a swollen wall?
Using such a refrigerator can be dangerous. If the swelling is caused by freon pressure, there is a risk of rupture of the system and the release of oil, which can ignite if it comes into contact with the electrical contacts of the compressor. In addition, violation of thermal insulation leads to overload of the electrical network.
How much does it cost to repair a swollen wall?
The cost depends on the cause. Replacing the outer sheet metal is inexpensive. If the evaporator needs to be overcooked and the insulation replaced, the price can be up to 70% of the cost of a new refrigerator, which often makes repairs economically unfeasible.
Is it possible to seal the bulge with a sealant?
No, the sealant will not withstand the internal pressure and will not restore the thermal insulation properties. This is a temporary measure that will not solve the problem, but will only hide it for a short time, allowing the problem to worsen inside the structure.
Why does the wall swell only in old refrigerators?
Not only in old ones. However, in older models, corrosion and wear of the insulation are more common. In new models with the No Frost system, bloating is more often associated with manufacturing defects during foaming or mechanical damage during transportation.