The appearance of extraneous sounds in the operation of household appliances always causes concern, especially when it comes to such an important unit as a refrigerator. If you notice that your No Frost emit a characteristic crackling sound, similar to the cracking of wood or clicks of plastic, this can be either a sign of normal operation of the system or a signal of an incipient breakdown. Unlike older models with a drip defrosting system, equipment with automatic moisture removal has a more complex design, including fans and heaters that create a specific acoustic background.
Often owners begin to panic ahead of time when they hear the first unfamiliar sound, but the nature of the noise can be completely harmless. Thermal deformation internal parts is a physical process that occurs in every refrigerator during changes in temperature conditions. However, if the cracking becomes loud, rhythmic, or accompanied by a humming sound, it cannot be ignored. Timely diagnostics will help to avoid costly repair of the compressor or complete replacement of the evaporator.
In this article we will analyze in detail all the possible causes of cracking, from natural physical processes to critical electrical faults. You will learn how to carry out initial diagnostics yourself, what tools you may need, and in which cases calling a specialist is the only right decision. Understanding the structure of your model Bosch, LG or Atlant will allow you to quickly localize the problem.
Natural causes of noise: thermal deformation
The most common and safest reason why a refrigerator cracks lies in the physics of materials. The inner walls of the chamber, the evaporator and the plastic elements of the housing have different coefficients of thermal expansion. When the compressor starts and begins to cool the chamber, or, conversely, the defrost heater turns on, the temperature of the parts changes sharply. The plastic contracts or expands, producing a characteristic sound, which is often compared to the crackling of a fire or walking in the snow.
This effect is especially often observed in new refrigerators or after defrosting. Thermal deformation is a standard process that does not require the intervention of a repairman. Typically, such sounds do not last long, only a few minutes after turning on or off the motor, and are not accompanied by other alarming symptoms, such as cooling failure or the formation of puddles on the floor.
It is worth considering that the intensity of the sounds may depend on the quality of the plastic used by the manufacturer. In cheaper models or, conversely, in premium devices with complex geometry of internal shelves, the resonance can be more pronounced. If the sound becomes similar to gunshots or is accompanied by vibration of the housing, it is necessary to check the stability of the unit and the absence of contact of the tubes with the housing.
Problems with the defrosting system: ice and fan
A more serious cause of crackling noise in the systems No Frost is a violation of the defrosting cycle. In such refrigerators, moisture from the food is blown by a fan onto the evaporator, where it freezes. It turns on periodically Defrost heating elementwhich melts the formed ice. If this process is disrupted, a massive coat of ice grows on the evaporator, which begins to interfere with the operation of the fan.
The fan blades, rotating, touch frozen blocks of ice, which causes a rhythmic crackling, knocking or grinding sound. This condition is dangerous because the fan motor can burn out from overload, and the evaporator itself can become deformed. Often this sound intensifies when you open the door, since in some models the fan continues to work or starts at this very moment.
How to check the frost without disassembling?
Carefully lean your ear against the back wall of the refrigerator or freezer. If the crackling sound comes from there and is rhythmic (in rhythm with the rotation of the blades), the probability of freezing of the evaporator is more than 80%.
To eliminate this problem, you will need to completely defrost the refrigerator. It is necessary to disconnect the device from the network, empty the chambers of food and leave the doors open for at least 12, and preferably 24 hours. Only complete melting of the ice in the hidden evaporator box will return the system to functionality. If after defrosting the problem returns after 1-2 weeks, it means that one of the elements of the defrosting system is faulty: the timer, the sensor or the heater itself.
Malfunctions of the compressor and start relay
If the crackling noise is heard not from inside the chambers, but from the bottom at the back where the motor is located, this may indicate problems with compressor or its wiring. One of the culprits could be the start relay. When the engine starts, the relay makes a clicking sound - this is normal. But if the relay is faulty, it may click repeatedly, trying to start the compressor, but not succeeding. In this case, the refrigerator hums, crackles, but does not cool.
Another reason is the vibration of the compressor itself. If the mounting bolts are loose or the rubber shock absorbers are worn, the motor housing may vibrate and touch adjacent tubes or cabinet walls. This metallic rattling sound is often mistaken for a crackling sound. It is also worth checking whether the copper tubes are touching each other or the body of the refrigerator - during operation they vibrate and over time can fray or make noise.
- 🔇 Rhythmic clicking every few minutes is a sign of an attempt to start a faulty compressor or the protection has tripped.
- 🔇 Metallic ringing when the motor is running - most likely the tubes touch the housing or each other.
- 🔇 Loud crackling sound at the moment of stopping —water hammer in the compressor is possible, which requires urgent diagnosis.
⚠️ Attention: If you hear a loud crackling sound in the area compressor and you smell burning or burning plastic, immediately unplug the refrigerator. Continuing operation may lead to a fire or complete engine failure.
The influence of dishes and food on acoustics
Sometimes the source of irritating sound is not in the bowels of the equipment, but on the shelves. Glassware, liquid bottles, or plastic containers may resonate with the vibration of the unit. If the shelves are not installed tightly or have factory defective fasteners, they may make a cracking or rattling sound, which can easily be confused with a broken mechanism.
Check how the bottles and cans are positioned. The liquid in them may gurgle or create resonance when the shelves vibrate. It is also worth inspecting egg trays and door shelves - empty plastic elements often rattle. It is enough to rearrange the items or place a silicone mat under them to eliminate the noise.
Pay attention to the drawers in the freezer. If they are skewed or there is too much food stuffed in them, when the fan or motor vibrates, they can touch the walls of the chamber, producing an unpleasant grinding sound. Remove the drawers, check the integrity of their guides and try to start the refrigerator without them.
Diagnostics and table of symptoms
To accurately determine the cause of the noise, it is important to correctly classify the sound and the conditions under which it occurs. Below is a table that will help you navigate the nature of the malfunction before calling a technician or starting repairs yourself.
| Sound type | Localization | Probable cause | Urgency of repair |
|---|---|---|---|
| Quiet crackling, clicking | Inside the chamber, walls | Thermal deformation of plastic | Not required |
| Loud grinding noise | Rear wall (freezer) | The fan touches the ice | Medium (needs defrosting) |
| Frequent clicks, humming | Bottom rear (compressor) | Start relay malfunction | High (risk of motor burning) |
| Metal vibration | Pipes, motor housing | Tube contact, loose fasteners | Low (you can fix it yourself) |
Using this data, you can preliminary assess the scale of the disaster. If the symptoms indicate electrical problems (relay, compressor), it is better not to take risks. However, if we are talking about ice, you can handle it yourself.
Instructions for self-defrosting
If diagnostics indicated freezing of the evaporator, it is necessary to carry out a complete defrost. This is the only correct solution to eliminate the crackling sound of a fan on ice at home. The process requires time and adherence to a sequence of actions so as not to damage the equipment.
First, completely empty the refrigerator of food. If it’s winter outside, you can take the food out to the balcony, but make sure that it doesn’t freeze (for the refrigerator) or defrost (for the freezer). Then disconnect the device from the power supply. Leave the doors wide open.
☑️ Correct defrosting algorithm
It is strictly forbidden to use a hair dryer, hot water or a knife to speed up the thawing of ice. Evaporator heating element and plastic parts are very sensitive to temperature changes and mechanical damage. You may puncture the evaporator passages, making repairs uneconomical. Allow the ice to melt naturally.
⚠️ Attention: Do not turn on the refrigerator until the moisture inside the chambers and on the floor is completely dry. If water gets on the electrical contacts or in the compressor area, it can cause a short circuit.
When you need to call a specialist
Despite the ability to independently eliminate many faults, there are situations when professional intervention is required. If, after complete defrosting, the cracking noise resumes after a couple of days, it means there is a malfunction in the defrosting system. The defrost sensor, timer, or heating element itself could have failed.
Also, the help of a technician is needed if the cracking sound is accompanied by a lack of cold. This indicates deeper problems: a freon leak, a clogged capillary tube, or a compressor malfunction. In these cases, special tools are required: leak detectors, gauge manifolds and vacuum pumps.
Why can’t you change freon yourself?
Replacing the refrigerant requires not only pumping gas, but also evacuation of the system to remove moisture and air. Without a vacuum sealer, the compressor will quickly burn out and the refrigerator will stop freezing.
Do not ignore the repeated clicks of the relay. If you replace the relay yourself, but the reason was in the compressor itself (for example, an interturn short circuit), the new relay will burn out instantly. Motor diagnostics require measuring the resistance of the windings and checking the current consumption, which is best left to an expert.
Prevention of noisy operation
In order for your No Frost to work quietly and for a long time, it is important to follow the operating rules. Carry out preventive defrosting regularly, at least once a year, even if there is no visible ice. This will help avoid the accumulation of “hidden” ice in hard-to-reach places in the air circulation system.
Keep an eye on the gap between the back wall of the refrigerator and the wall of the room. For normal operation of the condenser and reduction of vibration, a distance of at least 10-15 cm is necessary. Also periodically check the installation level of the refrigerator using a building level - misalignment can increase vibration and noise of the compressor.
Is it possible to lubricate a fan if it is cracking?
Lubricating the fan bearing in modern refrigerators usually does not make sense, since they often unattended. If the fan makes a cracking noise, the bearing is most likely already damaged or ice has gotten into it. The best solution is to replace the entire unit.
Why does a newly purchased refrigerator crack?
New equipment often makes sounds of thermal deformation, since the plastic has not yet gone through expansion-compression cycles. Also, the compressor may have become dislodged during transportation. Let the refrigerator stand for 2-3 hours before turning it on and check the fastening of the motor.
Is it dangerous to ignore the cracking of ice?
Yes, it is dangerous. If the fan runs for a long time, touching ice, it may jam. This will stop the air circulation, overheat the fan motor and possibly melt the plastic parts of the chamber.