Detection of deformation of the body of refrigeration equipment is always an alarming signal for the owner, requiring immediate attention. If the back wall of the refrigerator is swollen, this may indicate a violation of the production technology, failure of the defrost system, or, less commonly, mechanical damage to the internal evaporator. Ignoring this symptom often leads to more serious consequences, including loss of circuit tightness and compressor failure.
Visually, the defect can manifest itself in different ways: from a barely noticeable bulge on a metal sheet to significant peeling of a decorative panel. Metal deformation is often accompanied by a change in the acoustic properties of the unit - new noises may appear or humming. In some cases, swelling is accompanied by the appearance of condensation on the outside of the case, which indicates a violation of the thermal insulation.
Modern models of household appliances, especially the budget segment, often have thin walls that are sensitive to changes in pressure and temperature. Polyurethane foam insulation, filling the space between the internal and external contours, under certain conditions may expand or lose its properties, pushing the metal out. Understanding the exact cause is necessary to choose the right restoration strategy.
Main causes of case and insulation deformation
The most common reason for the rear wall of a refrigerator to swell is a violation of the foaming process during production. If the manufacturer skimped on materials or violated technology, voids may form in the insulation layer. Over time, the gases used in foaming can expand under the influence of heat from a running compressor or condenser, creating pressure on a thin sheet of metal.
Another serious reason lies in the No Frost system. If defrost heater fails or the timer stops turning on the defrost mode, a huge coat of ice grows on the evaporator. Ice takes up more volume than water and can mechanically press on the back wall from inside the chamber, bending it towards the kitchen. In this case, deformation is often accompanied by problems with cooling.
It is also worth considering the thermal expansion of materials. Metal and plastic have different expansion coefficients. With frequent and sudden temperature changes, for example, with improper defrosting using a hairdryer or hot water, the materials may deform unevenly. Plastic lining the inner chamber may lose rigidity and bend, taking the metal case with it.
⚠️ Attention: If the bloating is accompanied by hissing, whistling or the smell of oil, immediately unplug the device. This may indicate depressurization of the refrigerant circuit.
Diagnostics: how to determine the source of the problem
Before taking active action, it is necessary to accurately localize the location and nature of the swelling. Primary diagnosis is carried out visually and by touch. Gently run your hand along the surface of the back wall - if the metal is hot and the bulge is in the area where the condenser passes (often these are the side or rear panels), this may be normal for some models where the tubes are mounted into the wall, but strong bulging is still a defect.
For deeper diagnostics, partial disassembly will be required. You will need to remove the back plastic panel inside the refrigerator or freezer (depending on where the problem is noticed). This will allow you to assess the condition evaporator and amount of ice. If you see that an ice layer several centimeters thick is pressing on the wall, the problem lies in the defrost system.
Check the integrity of the inner box. If the plastic is cracked or separated from the metal, it creates the appearance of swelling. In some cases, the screws holding the evaporator or fans in place may be too tight or become misaligned, creating a pressure point on the wall. Use a flashlight to inspect hard-to-reach places.
☑️ Primary diagnostics
Repair of the defrost system due to freezing
If the cause of swelling was ice accumulated on the evaporator, it is necessary to restore the operation of the No Frost system. Most often, the culprit is Defrost heating element, which burns out and stops heating. Also, the defrost sensor often fails, which does not give a command to turn on the heater, or the timer itself (control module), which does not switch operating cycles.
The repair process begins with complete defrosting of the unit. The refrigerator must be left turned off for at least 24 hours for all the ice, including that hidden in the insulation, to melt. Attempts to chip the ice with a knife or beat it off are strictly prohibited, as this is guaranteed to lead to breakdown of the evaporator tubes and leakage of freon.
After defrosting, faulty elements are replaced. To check the heating element, use a multimeter in resistance measurement mode. The normal resistance of a working heater is usually between 200 and 400 ohms. If the device shows a break (one on the screen), the element must be replaced. The defrost sensor is checked in the same way.
| System element | Function | Symptoms of malfunction | Checking method |
|---|---|---|---|
| Defrost heating element | Heating the evaporator to remove ice | Increasing "fur coat", swelling of the wall | Test with a multimeter |
| Defrost sensor | Evaporator temperature control | Heating does not turn on or heats constantly | Resistance measurement |
| Timer/Module | Switching cooling and defrosting cycles | Chaotic operation, no defrosting | Checking the output voltage |
| Fan | Air circulation | Noise, uneven cooling | Visual inspection and rotation test |
Difficulties with access to the heating element
In some models of Indesit or Atlant refrigerators, access to the defrost heater may be difficult. Often it is necessary to dismantle the entire evaporator, which entails unsoldering the tubes and subsequent charging with refrigerant. In such cases, do-it-yourself repairs become economically unfeasible.
Elimination of insulation defects and swelling
The situation when the wall is swollen due to problems with foam is one of the most difficult. If polyurethane foam continues to expand or has moved away from the metal, simply pushing the wall back will not have a long-term effect - the material will tend to return to its shape. In mild cases, you can try mechanical pressing.
For this, the “iron” method is used. A heated (but not red-hot) iron is applied through several layers of thick fabric to the swollen area. Heat softens the top layer of plastic and makes the metal more ductile. Simultaneously with heating, the deformation site is strongly pressed with a heavy load or clamps with wide spacers. This method only works if the insulation is not under strong gas pressure.
In more serious cases, surgery is required. At the point of maximum swelling, carefully drill a small hole (2-3 mm) in the outer metal, being careful not to damage the internal contour. Through this hole you can try to extract excess foam or release gas. The hole is then filled with low expansion foam and painted over. However, this violates the factory tightness and aesthetics.
⚠️ Attention: When working with polyurethane foam, use a respirator and gloves. The chemical components of the foam are toxic until complete polymerization and can cause an allergic reaction.
Restoring the geometry of the metal body
If the cause of the swelling has been eliminated (for example, the ice has melted and the defrost system has been repaired), but the dent or hump remains, you can try to level the metal. For thin sheet steel used in refrigerators, the extrusion method is suitable. Remove all obstructing elements from the rear technical panel.
Using a wooden or rubber hammer, gently tap the edges of the deformation, moving from the periphery to the center. Do not hit too hard into the center of the bulge - this may cause a “hump” to form in the opposite direction. The main task is to relieve the internal stress of the metal. If the wall is double (sandwich), it is almost impossible to level it perfectly without disassembling it.
To fix the result, you can use epoxy glue or special automotive putties, which are applied to a degreased surface after leveling. This will create an additional hard layer that prevents the deformation from returning. It is important to choose a putty that is resistant to vibration and temperature changes.
Prevention of re-occurrence of defects
To prevent the problem of the back wall from swelling again, it is important to follow the operating rules. Check the door seals regularly. If they do not fit tightly, moist air enters the chamber, which instantly turns into ice on the evaporator, creating excess pressure.
Do not install the refrigerator close to the wall. For models with a foamed condenser (the sides get hot) or a classic grille at the back, a gap of at least 10-15 cm is required for free air circulation. Overheating of the rear can cause expansion of materials and gases in the insulation.
Keep the drainage hole clean. If the water does not leave the defrost, it freezes at the bottom of the chamber, gradually raising the ice level higher and higher, until it comes into contact with the back wall. Clean the channel with a hedgehog or warm water every six months.
When you need to call a technician
Exist situations where independent repairs can lead to permanent breakdown of the unit. If you find that along with the swelling of the wall, freon has escaped from the system (a whistle is heard, there are oily spots), you cannot do without special equipment and sealing skills. The technician will need a vacuum pump, a pressure gauge station and refrigerant.
Also, the help of a professional is needed if swelling occurs in the area where the tubes are sealed. The metal there is thin and burns easily. Unqualified intervention in refrigeration circuit is dangerous. If the refrigerator is under warranty, any independent repair will lead to its loss.
In the case where the deformation is caused by a factory defect in the insulation (swelling over the entire area), warranty repairs often involve replacing the entire cabinet or unit, since it is impossible to locally correct the factory foam. The service center technician will be able to diagnose this and issue a malfunction report.
Is it possible to use the refrigerator if the wall is swollen?
If the swelling is minor and is not accompanied by a freon leak (no smell, hissing, the refrigerator is freezing), operation is possible. However, watch the dynamics: if the swelling grows, it can lead to rupture of the inner box and loss of seal.
Why is the back wall hot and swollen?
In modern refrigerators, the condenser is often located inside the side or rear walls. Their heating to 50-60 degrees is the norm. But if the metal is swollen, it means that heat transfer is impaired, or the insulation has moved away from the metal, creating an air cushion that does not remove heat well.
How to seal cracked plastic inside the refrigerator?
To repair internal plastic (ABS), it is best to use special repair kits for plastic or food-grade epoxy compounds. Regular silicone or Moment glue can be toxic and cannot withstand low temperatures, becoming brittle.
How much does it cost to repair a swollen wall?
The cost depends on the cause. Replacing the defrost heating element is inexpensive. If re-foaming or replacement of the cabinet is required, the cost can reach 70-80% of the price of a new refrigerator, which makes repairs economically unfeasible.