A sudden crash coming from the kitchen can scare any owner of household appliances. Often this sound occurs unexpectedly, making you wonder if the unit has broken down or if the contents have gone missing. However, such sounds do not always indicate a critical malfunction.
In most cases clicks and crackles they are a natural part of the operating cycle of modern refrigeration units. Understanding the physics of the processes occurring inside the case will help you distinguish normal operation from a real breakdown. Let's look at the main scenarios.
Natural physical processes during compressor operation
The most common cause of extraneous sounds lies in the operation of the compressor unit. When the engine starts or stops, the refrigerant pressure in the system changes sharply. This causes vibration of the metal tubes and the motor housing itself, which we hear as a dull knock or short crackling sound.
In addition, when turning it on and off electric relay a characteristic click occurs. This is a normally functioning starter mechanism that supplies voltage to the motor windings. If the sound is heard once at the beginning or end of the cooling cycle, there is no need to worry.
It is important to note that new models of equipment may behave differently than old Soviet models. Modern inverter compressors operate more smoothly, but can produce a high-frequency hum or quiet crackling when adjusting power.
Sometimes users notice that The refrigerator is cracking it is after defrosting or loading a large amount of warm food. This is due to the fact that the unit goes into intensive operation mode, and the load on the system increases.
If the sounds become metallic, ringing, or are accompanied by a hum that does not stop for hours, you should pay attention to the condition of the fasteners and shock absorbers.
Thermal expansion of the body materials and evaporator
Another common reason why a refrigerator cracks is banal physics. The inner walls of the chamber, shelves and, most importantly, evaporator are made of materials that contract when cooled and expand when heated.
This process is called thermal expansion. When the compressor turns off and the temperature inside begins to rise, or, conversely, drops sharply upon startup, plastic and metal emit a characteristic crackling sound, reminiscent of the sound of a bursting bubble or snapping of fingers.
This effect is especially noticeable in models with the system No Frost. There, temperature changes are sharper due to the operation of fans and defrost heating elements. Typically, such sounds appear in the form of a series of clicks after the end of the cooling cycle.
⚠️ Attention: If the cracking sound is accompanied by a burning plastic smell or smoke, immediately unplug the device. This may indicate overheating of the wiring or melting of parts.
It is worth considering that the intensity of the sounds may depend on the quality of the plastic used by the manufacturer. Cheap polymers can crack louder and more often than high-quality engineering plastic.
The influence of food temperature
If you put a hot pan in the chamber, thermal shock can cause severe cracking of the walls and even damage the glass of the shelves. Always cool food to room temperature before placing it in the refrigerator.
Problems with the fan in No Frost systems
In refrigerators with an automatic defrost system, fanis responsible for air circulation. If you hear a crackling noise that sounds more like a chirping or propeller noise, the problem may lie in this particular unit.
Over time, an ice crust may grow on the fan blades, especially if the door seal is broken or access to the chamber is often opened. Ice interferes with free rotation, causing friction and a characteristic crackling sound.
Fan motor bearings may also fail. In this case, the sound will be constant while the blower system is operating. For diagnostics, it is often necessary to remove the back wall of the freezer.
Complete defrosting of the unit can be a solution to the problem. If the sound disappears after 24 hours of being turned off, it means the problem was ice. If the cracking noise remains, you will need fan replacement.
☑️ Fan diagnostics
The influence of improper installation and alignment
Sometimes the answer to the question of why the refrigerator is cracking lies not inside, but outside. Incorrect installation leads to misalignment of the housing, due to which parts begin to touch and vibrate when the compressor operates.
Check whether the unit is stable on the floor. If it wobbles, it is necessary to adjust the height of the front supports. An uneven floor surface can also cause movement and subsequent vibration noise.
Also, make sure that the back of the refrigerator does not touch the kitchen wall or furniture. The gap should be at least 5-7 centimeters for free air circulation and absence of resonance.
| Sound type | Probable cause | Urgency of repair |
|---|---|---|
| Single click | Relay operation or thermostat | Not required |
| Plastic crackling | Thermal expansion | Not required |
| Wheeling/Humming | Fault fan | Medium |
| Metal clanging | Problems with the compressor | High |
Do not forget that vibration from a running motor can be transmitted to those nearby items. Check whether the refrigerator is touching other equipment, furniture or dishes installed on its roof.
Malfunctions of the starting relay and compressor
If the crackling noise is heard regularly and is accompanied by attempts to start the motor, followed by silence, the problem can be serious. The part responsible for starting the engine often fails. starting relay - a part responsible for starting the engine.
Inside the relay there is a coil and contacts that burn out or stick over time. When voltage is applied, a click occurs, but the engine does not start, and the protection system opens the circuit again. This cycle can be repeated every few minutes.
A more serious situation is the wear of the compressoritself. If the piston group is worn out, knocking and clanging of metal on metal may occur inside. In this case, the unit usually requires replacement, since repair is not economically feasible.
⚠️ Attention: Do not try to repair the compressor yourself without skills in working with refrigeration equipment and vacuuming the system. This is dangerous and difficult.
You can diagnose a problem with the relay if you carefully (following safety precautions and turning off the power) remove the protective cover from the back and listen to where exactly the sound is coming from. Often you can replace the relay yourself by selecting an analogue according to the marking.
Deformation of internal elements and trays
Internal components can also become a source of crackling: glass shelves, plastic trays or containers for vegetables. When the temperature changes, they may become slightly deformed and, in contact with the walls of the chamber, make sounds.
Check that all guides are tightly seated. Sometimes it is enough to adjust plastic stops or turn over the glass shelf to eliminate rattling.
Also pay attention to the products. Heavy cans that are standing may fall or move when vibrated, creating noise. Make sure that the door shelves are not overloaded.
In some cases, the door itself causes the cracking noise if the hinges are loose or the seal is skewed. When opening or closing, as well as during ventilation, the door may move slightly, touching the body.
The “memory” effect of plastic
Cheap plastic trays lose elasticity over time and begin to crack even with minimal impact. Replacing such elements with original ones often solves the noise problem.
When you need to call a technician
To summarize, we can say that single clicks and quiet crackling sounds of plastic are the norm. However, there are signs that cannot be ignored. If the noise becomes loud, constant or changes in character, professional diagnostics are needed.
Be sure to contact the service if the cracking noise is accompanied by a lack of cold, the appearance of ice in unexpected places, or if the refrigerator begins to consume more electricity.
A timely contact with a specialist will help avoid costly repairs or complete replacement of the unit. The technician will be able to accurately determine whether the sound is a consequence of natural wear and tear or a critical breakdown.
Is it normal for the refrigerator to crack immediately after defrosting?
Yes, this is absolutely normal. After defrosting, the internal elements (plastic, metal) heat up, and then cool down sharply when turned on. The process of thermal expansion/contraction during this period is more intense, so the cracking may be more frequent and louder in the first hours of operation.
Can a new refrigerator crack?
Yes, new models often make sounds when “grinding in” parts. In addition, in new technology, heat transfer processes may be more pronounced due to fresh materials. Usually, after 1-2 weeks of operation, the noise level stabilizes.
Is it dangerous if the crackling noise is heard only at night?
At night, the overall noise level in the apartment decreases, so even standard operating sounds of the refrigerator (compressor turning on, fan running) become more noticeable. If the nature of the sound has not changed, there is no danger.
Does the voltage level in the network affect the crackling sound?
Yes, with low voltage in the network, it is more difficult for the compressor to start. The start relay may click more frequently as it tries to start the engine, creating a characteristic whirring sound. In such cases, it is recommended to use a voltage stabilizer.