Faced with a situation where the back wall of the refrigerator is cracking, many equipment owners immediately panic, expecting expensive repairs or a complete replacement of the unit. However, the characteristic sound, reminiscent of cracking plastic or clicks, does not always indicate a critical breakdown. In most cases, this is a physical phenomenon associated with temperature changes and the characteristics of the materials from which the body and internal lining are made.
You need to understand that modern refrigerators are complex thermodynamic systems where the cooling and heating processes occur cyclically. Back wall, especially in models with a No Frost or drip system defrosted and constantly exposed to extreme temperatures. The plastic from which the internal panels are made and the metal of the external case have different coefficients of thermal expansion, which often leads to sounds that frighten inexperienced users.
In this article we will analyze in detail all the possible reasons why refrigerator cracking, dividing them into natural physical processes and technical malfunctions. You will learn to independently diagnose the problem, distinguish normal operation from a breakdown, and understand in which cases it is really necessary to call a specialist, and when it is enough to just wait.
Physics of the process: thermal expansion of materials
The most common and absolutely safe reason for cracking is physics. When compressor operates, it pumps out refrigerant, which cools the internal components. At this moment, the temperature of the rear wall drops sharply, sometimes to sub-zero values. Materials are compressed. When the cooling cycle ends and the motor turns off, the temperature begins to rise and the materials expand again.
This process is called thermal expansion. Since different parts of the structure (plastic, insulating foam, metal evaporator) heat and cool at different rates, friction or momentary displacement occurs between them. It is this displacement that we hear as a loud crack or click. This happens especially often in new refrigerators or after defrosting.
⚠️ Attention: If the crackling sound occurs exclusively when the motor is turned on or off and is intermittent, most likely everything is fine with your refrigerator. This is normal operation of the system.
The intensity of sounds may depend on the quality of the plastic used by the manufacturer. Budget models often have thinner internal panels that respond more loudly to temperature changes. Over time, when the plastic “gets used” to the operating modes, the sounds may become quieter, but will not disappear completely.
Natural sounds of the No Frost system
If you have a model with the system No Frost or Full No Frost, then the cracking of the rear wall may be associated with the operation of the system automatic defrosting. In such refrigerators, frost periodically forms on the evaporator, which is often hidden behind the back panel inside the chamber. To remove it, the heating element is turned on - defrosting heating element.
The defrosting process is accompanied by a sharp change in temperature. The ice melts into water, and the plastic elements that were frozen suddenly heat up. This temperature contrast causes characteristic sounds that users describe as crackling sounds, crunching snow, or even gunshots. This is normal for this technology.
The frequency of such sounds depends on the controller settings and the humidity of the products. Defrosting usually occurs several times a day. If you notice that the crackling noise intensifies at certain times, check the operating mode of your device. In some models, you can increase the intervals between defrosts through the settings menu, which will reduce the frequency of sounds.
How does the defrost sensor work?
The defrost sensor monitors the temperature of the evaporator. When ice freezes, the temperature drops, and the sensor gives a command to turn on the heating element. If the sensor is faulty, the defrost may turn on too often or not at all, resulting in either a constant rattling noise or the formation of an ice coat.
Compressor mounting problems and vibration
Sometimes what appears to be a cracking sound in the back wall is actually vibration transmitted from the compressor to the housing. If shock absorbers or the rubber gaskets under the engine are worn out, have lost their elasticity, or were installed incorrectly after repair, vibration is transmitted to the metal frame and rear grille.
In this case, the cracking will be accompanied by buzzing or rattling. The back wall, being part of the structure, resonates and amplifies the sound. This is especially noticeable if the refrigerator is not level or touches the back of the wall or furniture. Check the distance between the rear wall of the unit and the wall of the room - it should be at least 5-7 cm for free air circulation.
- 🔊 Check that the condenser tubes do not touch each other or the walls of the housing.
- 🔧 Make sure that the transport bolts (if they were on the compressor) are completely removed.
- 📏 Level the legs of the refrigerator using a building level.
To diagnose this problem, you can carefully (observing safety precautions) press the back grille or the body itself with your hand at the moment the sound appears. If the nature of the noise changes or the crackling stops, then the problem is resonance or vibration. In this case, it may be necessary to replace the rubber washers under the compressor.
Faults in the thermostat and start relay
A more serious cause of the crackling noise may be electrical components. Thermoregulator (thermostat) is responsible for turning the compressor on and off. There are contacts inside it that can make a loud click when the circuit opens. If this click is accompanied by sparking or is heard too often, the device may need to be replaced.
A similar situation with start relay. This element starts the compressor motor. When faulty, the relay may make a series of rapid clicks, attempting to start the engine but failing to do so. In this case, the refrigerator may hum and click, but not cool. This already requires the intervention of a specialist.
| Symptom | Probable cause | Actions |
|---|---|---|
| Single click when stopping | Thermal expansion (Normal) | Do nothing |
| Series of clicks, no cold | Faulty start relay | Call a technician |
| Loud crackling noise when turning on the light | Problem with the thermostat | Replacing the thermostat |
| Constant cracking of ice | No Frost system operation | Check the drainage |
Diagnosing an electrical fault on your own is quite difficult and dangerous without special instruments. If you notice that clicks are accompanied by a burning smell or the refrigerator has stopped freezing, immediately unplug it.
The influence of ice and the condition of the drainage system
In refrigerators with a drip system or a mixed type, the cracking noise can be produced by the ice itself. If drain hole clogged with food particles or dirt, the water does not go into the tray, but freezes on the back wall. When the compressor is turned on, this ice cracks, bursts or chips, creating characteristic sounds.
In addition, large pieces of ice can put pressure on plastic panels or air duct dampers. When the temperature changes, the ice deforms and makes sounds similar to the cracking of plastic. Regular defrosting and cleaning the drainage helps avoid this problem.
Check if there is a “coat” of ice on the back wall inside the chamber. If there is one, defrost the refrigerator completely (for 10-12 hours) with the doors open. After defrosting, clean the drainage hole using a special brush or soft wire.
☑️ Checking the drainage system
Plastic defects and manufacturing defects
Sometimes the reason lies in the quality of the materials. Cheap plastic becomes brittle at low temperatures and can crack not only from expansion, but also from mechanical stress. If you recently installed shelves or pressed hard on the back wall when loading products, a microcrack may have formed, which is now “walking” and cracking.
It is also worth inspecting the back wall for factory casting defects. The uneven thickness of the plastic causes different areas to cool at different rates, causing internal stress and a characteristic crackling sound. In rare cases, this can lead to destruction of the panel.
⚠️ Attention: If you notice visible cracks on the plastic panel inside the chamber, through which cold can escape or moisture can enter the insulation, it is better to stop using the refrigerator until repaired.
To fix the problem, you can try to carefully seal the crack with food grade sealant or Replace the plastic panel if it is sold separately as a spare part. However, if the crack is through and leads to a freon leak (which is rare, but possible in places where pipes are soldered behind the wall), the repair will be difficult.
When it is necessary to call a specialist
Despite the fact that most sounds are safe, there are situations when a cracking sound cannot be ignored. If other symptoms are added to the sounds, this is a signal of a serious breakdown. Do not try to disassemble the compressor or open the cooling system yourself - this requires a license and special equipment.
A technician should be called if the cracking sound is accompanied by loss of cold, the appearance of puddles under the refrigerator, the smell of burnt wiring, or if the motor hums but does not start after a series of clicks. Help is also needed if you are not sure about the nature of the sound and are afraid to leave the equipment on.
A timely call to a specialist will help avoid more expensive repairs, for example, replacing the compressor, if the problem was noticed at an early stage. Remember that diagnostics are often free or inexpensive if you refuse further repairs.
How much does diagnostics cost?
The cost of diagnostics depends on the region and service center. Usually it ranges from 500 to 1500 rubles. Often, when agreeing to repair, the cost of diagnostics is included in the total amount of work.
Prevention of noisy operation of the refrigerator
In order for your refrigerator to work quietly and please you only with a pleasant hum, it is important to operate it correctly. Defrost regularly, even if you have a No Frost system (once a year and a half for general cleaning). Keep the condenser at the back clean - dust and animal hair worsen heat transfer, causing the compressor to work harder and noisier.
Do not place the refrigerator close to the wall and make sure it is on a level floor. Avoid overloading shelves as this places additional stress on the cabinet structure. Proper operation extends the life of equipment and maintains silence in your kitchen.
In conclusion, we note: if The back wall of the refrigerator is cracking, in 90% of cases this is physics, not a breakdown. But you shouldn’t let your guard down. Listen to your equipment, and it will serve you for many years.
Why does the new refrigerator crack more than the old one?
New materials have not yet gone through cycles of compression and expansion, so their reaction to temperature changes is more pronounced. Over time, the plastic “settles down” and the sounds become quieter. Also, new models often have more powerful compressors and a complex insulation system, which can change the nature of the sounds.
Is it dangerous if a crash is heard at night?
At night, the overall noise level in the apartment decreases, and any sounds from equipment become more noticeable. If the cracking sound is associated with thermal expansion, it is not dangerous at any time of the day. However, if the sound interferes with sleep and seems unnaturally loud, it is worth checking the installation of the refrigerator.
Is it possible to lubricate the rubbing parts with oil?
It is strictly not recommended to lubricate the internal parts of the refrigerator, especially plastic and rubber seals, with ordinary oils. They can destroy the material or get into products. Only metal door hinges should be lubricated with special compounds if they creak.
Does the temperature in the room affect the cracking?
Yes, it does. The higher the room temperature, the longer and harder the compressor works to maintain the cold. This leads to sharper temperature changes on the back wall and, as a result, to more frequent and loud crackling sounds of materials.