Many owners of household appliances are faced with a situation where a refrigerator that previously worked silently starts making strange sounds. Crackling, clicking, humming or gurgling can be a real test for the nervous system, especially if the kitchen is combined with the living room. Users often panic, believing that the unit is about to fail, but these sounds do not always indicate a critical breakdown.
It is important to understand that modern refrigerators these are complex electromechanical systems in which processes of expansion and contraction of materials, circulation of refrigerant and the operation of electrical components are constantly occurring. In most cases, extraneous noise is normal, but there are also situations that require immediate intervention. In this article, we will look in detail at why a refrigerator cracks, how to distinguish normal operation from a malfunction, and what you can do yourself.
Before calling a technician, try to analyze the nature of the sound and the conditions under which it occurs. Is the cracking noise intermittent or constant? Is it related to turning on the motor? Answering these questions will help you diagnose the problem more quickly. Remember that timely identification of the cause of noise can save your compressor from overload and extend the service life of the entire device.
Natural causes of crackling: the physics of refrigerator operation
The most common reason why a refrigerator makes cracking or clicking noises lies in physical properties of materials. The internal chamber, shelves and external walls of the unit are made of plastic and metal. During operation, the temperature of these elements constantly changes: when the compressor is turned on, they are cooled, and during idle time they are heated to room temperature. This process causes thermal expansion compression of materials, which is accompanied by a characteristic crackling.
Such sounds are especially often heard in new refrigerators or after defrosting, when the temperature difference is greatest. The cracking sound may also become louder if you have just loaded a large amount of warm food into the chamber. In this case, the cooling system begins to work more intensely, causing sharper temperature changes on the walls of the evaporator and inside the plastic panels.
Another source of natural noise is the circulation of the refrigerant. Freon, moving through the pipes of the system, can make sounds resembling gurgling or a slight hiss. This is absolutely normal and indicates that refrigerant circulates freely along the circuit, performing its function of removing heat.
⚠️ Attention: If the cracking sound is accompanied by vibration of the housing or intensifies when touching the walls of the refrigerator, check the stability of the installation of the unit. An uneven floor can increase resonance.
Thus, if your refrigerator crackles irregularly, mainly when the motor is turned on or off, and the food is cooling normally, there is no need to worry. This is the normal operating mode laid down by engineers when designing the device.
Problems with the compressor and start relay
If the crackling noise comes from the bottom of the refrigerator, where the motor is located, and is of a harder, metallic nature, the reason may lie in the operation compressor. The compressor is the heart of the refrigerator, and any disturbance in its operation may be accompanied by extraneous sounds. Often a crackling or loud click is heard when you try to start the engine.
One of the common problems is a faulty start relay. This small element is responsible for supplying voltage to the compressor windings at start-up. If the relay is worn or dirty, the contact may not close the first time, resulting in a series of clicks and pops before the engine starts. In some cases, the motor may hum but not start, after which a loud click is heard and it turns off.
The compressor itself may also be the source of the sound. Wear on internal mechanical parts, such as pistons or valves, causes metallic knocking and rattling noises to occur during operation. If you hear that engine works with a clear clanging or vibration that is transmitted to the entire body, this is an alarming signal.
How to check the starting relay?
To check, you need to disconnect the refrigerator from the network, remove the back panel, find the starting relay relay on the compressor and carefully remove it. Shake the relay: if you hear a ringing sound inside (like a broken stone), it means that the ceramic tablet inside has cracked and the relay needs to be replaced.
It is important to note that problems with the compressor are often accompanied by other symptoms: insufficient cooling, overheating of the rear wall or frequent startup. If you suspect a malfunction in this part of the system, further operation may lead to complete failure of the unit.
Improper installation and ventilation
Often the cause of crackling and humming is trivial and lies in improper installation of the refrigerator. If the unit is not level, its body may warp, which leads to stress on the internal structures and the appearance of sounds when the vibration units operate. In addition, an unstable position causes shelves and drawers to rattle.
The distance to walls and furniture is a critically important parameter. For normal operation, the refrigerator requires free air circulation around the condenser (grids on the back or sides). If the refrigerator is moved close to the wall, heat exchange is disrupted, the compressor overheats and begins to work with increased load, which is often accompanied by increased noise and crackling.
Also check whether the refrigerator pipes are touching walls or other objects. The vibration of a running motor is transmitted to the pipelines, and if they come into contact with hard surfaces, a constant rattling sound occurs.
☑️ Checking the installation of the refrigerator
Eliminating installation errors often allows you to completely get rid of extraneous sounds without the need to disassemble the equipment. Make sure that the floor under the refrigerator is level and the legs fit snugly to the surface.
Icing and malfunctions of the No Frost system
In refrigerators with a system No Frost or drip defrosting, the cause of the cracking noise may be the formation of excess ice on the evaporator. When the ice layer becomes too thick, it can prevent the fan or air duct damper from operating. The fan blades, touching the ice crust, produce a characteristic cracking or scratching sound.
No Frost systems also use a heating element to defrost the evaporator. During the process of heating and subsequent cooling, this element, like any other parts, undergoes thermal expansion, which can cause clicks. However, if the cracking sound is heard frequently and is accompanied by a lack of cooling, the defrost cycle may be broken.
A malfunction of the defrost sensor or timer can lead to the fact that the ice does not have time to melt, increasing with each cycle. This not only creates noise, but also reduces the efficiency of the refrigerator. In such cases, complete defrosting of the unit is required (at least 24 hours) and, possibly, replacement of faulty sensors.
⚠️ Attention: Do not try to break off the ice from the evaporator with a knife or sharp objects. You can damage the refrigerant tubes, which will lead to expensive repairs and leakage of freon.
Regular maintenance and monitoring the condition of the door seals will help prevent excess moisture from entering the chamber and subsequent icing.
Table: Diagnostics of refrigerator sounds
To simplify diagnostics, we suggest that you familiarize yourself with a table that systematizes the main types of sounds and their probable causes. This will help you quickly navigate the situation.
| Sound type | Probable cause | Degree of danger | Actions |
|---|---|---|---|
| Rare crackling, clicking | Thermal expansion of plastic | Safe | Observation |
| Gurgling, hissing | Freon circulation | Safe | Observation |
| Loud clicking, humming | Problems with the starting relay | Average | Replacing the relay |
| Metallic knocking, clanging | Compressor wear | High | Call a technician |
| Fan crackling | Ice on blades, | Average | Defrost, cleaning |
Use this table as a primary guide. If the nature of the sound does not match those described or you doubt the diagnosis, it is better to play it safe and contact a specialist.
When you need to call a specialist
There are a number of situations when self-repair is not only ineffective, but also dangerous. If you notice that the cracking sound is accompanied by a burning smell, smoke or sparking, immediately unplug the refrigerator. Also an alarming sign is the appearance of puddles of water under the unit or on the kitchen floor, which may indicate a refrigerant leak or problems with the condensate drainage system.
If the refrigerator has stopped freezing, and the compressor is making strange sounds (humming but does not start, or running with strong vibration), this indicates a serious mechanical or electrical malfunction. Attempts to “revive” the compressor using traditional methods can lead to its final failure.
The technician will conduct diagnostics using pressure gauges and testers, pinpoint the cause of the noise and make the necessary repairs. In some cases, it may be necessary to replace the compressor or restore the tightness of the system.
Noise prevention and refrigerator care
In order for your refrigerator to operate quietly and for a long time, it is important to follow the operating rules. Check the door seal regularly. A loosely closed door allows warm air to constantly enter, which forces the compressor to work without interruption, causing overheating and noise.
At least once a year, defrost the refrigerator (if it is not a No Frost system) and wash the drainage hole. A clogged drain can cause water and ice to accumulate, which will also affect the acoustics of the unit. Wipe the rear grill from dust, as dust impairs heat transfer.
Try not to load hot foods into the refrigerator. This puts extra stress on the cooling system and causes excessive condensation and ice formation. Following these simple rules will help minimize the risk of extraneous sounds.
Remember that careful attention to technology is the key to its durability. If you hear a new, previously unfamiliar sound, do not ignore it. Early diagnosis allows you to solve the problem with minimal means.
Why does the refrigerator only crack at night?
At night, the overall noise level in the apartment decreases, and the sounds of operating equipment become more noticeable. In addition, at night the voltage in the electrical network may stabilize or, conversely, jump, which affects the operation of the compressor. Also, at night, the fast freezing mode is turned on more often or the doors are simply opened more often if there are people in the house who lead a nocturnal lifestyle.
Is it possible to lubricate the rubbing parts with oil?
You can lubricate the moving parts inside the refrigerator cabinet (dampers, drawer hinges) only with special food-grade lubricants or silicone oil. Regular machine oil can be toxic, have an unpleasant odor, and damage plastic parts. Lubricating the compressor or fan motor yourself is prohibited.
The cracking sound appeared after transporting the refrigerator. What to do?
If the refrigerator was transported lying down, oil from the compressor could get into the refrigerant circuit. In this case, the refrigerator cannot be plugged in for at least 4-8 hours (preferably a day) so that the oil flows back into the compressor. If you turn it on immediately, a water hammer and cracking noise is possible, leading to breakdown.
Does the quality of electrical wiring affect the crackling noise?
Yes, low voltage or poor contact in the socket can lead to the start relay not working correctly, causing clicks and humming of the compressor. Check the socket by connecting another appliance to it, or try turning on the refrigerator through a surge protector.