A sudden crackling sound in the refrigerator can scare any owner of household appliances, especially if the unit has just been purchased or, conversely, has already served faithfully for many years. Sound anomalies are often the first signal that changes are occurring within the system, which can range from completely harmless physical processes to serious mechanical malfunctions of the compressor or defrost system.
It is important to understand that modern climate control equipment, whether budget models Indesit or premium Liebherrcannot operate at full capacity silence, but the nature of the sounds made matters. If the usual hum has changed to sharp clicks, periodic crackling of plastic or the sound of breaking ice, it is necessary to carry out an initial diagnosis to eliminate the risk of food spoilage and expensive repairs.
In this article we will analyze in detail the physics of the occurrence of extraneous noise, methods for their localization and action algorithms for various scenarios. You will learn to distinguish the normal operation of the thermostat from the beginning destruction of parts, which will save time and money.
Natural physical processes: when noise is the norm
Often, equipment owners begin to panic ahead of time, mistaking the natural acoustic effects that accompany the operation of the refrigeration circuit for a breakdown. The refrigerant circulating through the tube system constantly changes its state of aggregation, moving from liquid to gaseous and back, which is inevitably accompanied by sound.
This is especially evident in models with the system No Frost, where the movement of freon is more intense. The cracking sound may resemble the sound of a bubble bursting or a short clicking sound that usually occurs immediately after the compressor stops or when it starts. This phenomenon is associated with changes in pressure in the evaporator and condenser tubes, the walls of which can be slightly deformed under load.
It is also worth considering the thermal expansion of materials. The inner plastic lining of the chamber and the outer metal panels have different expansion coefficients. If there is a sudden change in temperature, for example, after opening a door and warm air entering, the plastic may make a characteristic cracking sound as it cools down or heats up. This is absolutely normal for most brands, including Bosch i LG.
⚠️ Attention: If the cracking sound is accompanied by a burning smell or smoke, immediately unplug the device. This may indicate overheating of the wiring or an electric arc in the control circuit.
For a better understanding of the nature of the sounds, let's compare normal noises with signs malfunctions:
| Sound type | Occurrence frequency | Probable cause | Is repair needed |
|---|---|---|---|
| Quiet gurgling, overflow | Constantly or after stopping | Movement of refrigerant through the pipes | No |
| Single click | When starting/stopping | Thermal relay operation or metal expansion | No |
| Rhythmic crackling of plastic | After opening the door | Thermal expansion of materials | No |
| Loud crackling with vibration | Constantly during operation | Faulty compressor or fan | Yes |
Problems with the defrosting system and freezing of ice
One of the most common causes of a loud cracking noise in refrigerators with an automatic defrosting system is the formation of excess ice on the evaporator. When the layer of ice becomes too thick, it can interfere with the operation of the fan that moves cold air around the chamber. The fan blades begin to touch the ice build-up, producing a loud cracking or knocking sound.
The second scenario is associated with the defrosting process itself. If the heating element (heater) of the heater is turned on, and the ice block is large, a sudden temperature change can cause sound effects similar to the crack of breaking glass. This occurs due to the rapid expansion of water inside the ice structure or deformation of the plastic evaporator box.
Often the problem lies in a malfunction of the defrost timer or defrost sensor. If the system “forgets” to turn on the heating in time or, conversely, cannot complete the cycle, ice accumulates to a critical mass. In models Samsung i Atlant this is a common cause of the appearance of extraneous noise after 3-5 years of operation.
What will happen if you ignore the ice on the evaporator?
Gradually the ice will block the air circulation channels, the refrigerator will stop freezing, and the compressor will work without stops, which will lead to its overheating and failure.
To eliminate the problem, complete defrosting of the unit is often required. It is necessary to turn off the refrigerator, empty the compartments of food and leave the doors open for at least 12-24 hours. Only complete melting of the ice in hard-to-reach places (behind the back wall) will help remove the sound.
- 🧊 Check to see if “snow” has frozen on the back wall of the freezer.
- 🔌 Make sure the drainage hole is not clogged with debris or ice.
- 🌡️ Please note pay attention to the operation of the thermostat - perhaps it does not read the temperature correctly.
Faults in the compressor and start relay
The heart of the refrigerator - the compressor - can also become a source of alarming crackling noise. In good condition, it emits a smooth, monotonous hum. If you hear a metallic clang, frequent clicks or intermittent crackling sounds, especially when you try to start, this indicates problems in the electrical or mechanical part of the motor.
Most often, the culprit is the "shooting" and crackling noise when starting. start relay. This small element is responsible for supplying current to the motor windings. If the relay contacts are oxidized or the mechanism is jammed, it begins to turn on and off randomly, making loud clicks. In this case, the compressor may not even start, just hum for a few seconds.
A more serious situation is wear of the internal mechanical parts of the compressor (piston group). If the liners or valves are worn out, metallic knocking and crackling noises occur when the engine is running. In units with an inverter compressor (for example, LG Linear), the nature of the sounds may differ, but mechanical wear also makes itself felt through vibration and noise.
⚠️ Attention: If the compressor hums, clicks, but does not start, and at the same time gets very hot, turn off the device. Long-term operation in this mode will lead to burnout of the motor windings.
Diagnostics of the compressor requires caution. Touch your hand to the motor housing (usually the black “tank” at the bottom back). If it is hot to the point where it is impossible to hold your hand, or, conversely, is absolutely cold when trying to start, the problem is obvious.
Vibration of the body and foreign objects
Sometimes the source of the crackling turns out to be trivially simple. Vibration transmitted from a running compressor to the refrigerator body can cause rattling of poorly secured elements. The condenser tubes located at the back may touch each other or the cabinet wall, creating a metallic ringing or crackling sound with each motor pulsation.
It is also worth checking the area around the refrigerator. If the unit is placed close to a wall or furniture, vibration can be transmitted to them, causing resonance. The shelves inside the chamber often crack if unstable dishes are placed on them, or bottles rattle in the door.
In some cases, small objects (candy wrappers, caps, toys) could get inside the ventilation duct or behind the back panel, which begin to hit the blades when the fan is operating. This creates a very characteristic, loud and frightening crackling noise, which can easily be confused with engine failure.
☑️ Vibration diagnostics
To eliminate noise from vibration, it is often enough to move the refrigerator or place special anti-vibration pads under the legs. If the tubes dangle from the back, they can be carefully (without bending!) moved away from each other or secured with soft insulation.
Defects in the internal lining and plastic elements
The plastic used in modern refrigerators may lose its properties or become deformed over time. This is especially true for older models or equipment that was operated in violation of the temperature regime. Cracks in the plastic evaporator box or condensation tray can expand and contract, making sounds.
Often the cracking sound is made by the guides for shelves or drawers. If the plastic is "tired", it may squeak or crackle at the slightest air movement or vibration. In the freezer, the plastic becomes more brittle, and any load (for example, a full box of food) can cause sound effects.
On models with water or ice dispensers, the feed mechanisms may become a source of noise. An ice cube stuck in the groove or a faulty ice supply motor will produce a rhythmic cracking or knocking noise that can be easily localized by opening the freezer door.
- 🔍 Inspect the back wall inside the chamber for cracks.
- 🗑️ Check the water drain tray above the compressor - it may be displaced.
- 🧊 Make sure the freezer drawers are not overcrowded and move freely.
When to call a professional: critical signs
Despite the fact that many sounds are safe, there are a number of signs that cannot be ignored. If the cracking sound is accompanied by a loss of cold (food begins to deteriorate, the chamber becomes warmer), this indicates a freon leak or compressor failure. In such cases, independent repair is impossible and you need to call a specialist.
Also an alarming signal is the appearance of the smell of burning wiring or rubber along with a crackling sound. This is a direct indication of an electrical fault that may cause a fire. If you notice sparking inside the housing or in the compressor area, immediately turn off the power to the device.
Do not delay repairs if the crackling becomes louder every day or a new tone of sound appears (for example, a howl or grinding sound has been added to the crackling). Early diagnosis allows you to replace a cheap part (relay, fan), avoiding the purchase of a new compressor.
⚠️ Attention: Repairing the refrigerant circulation system requires a license and special equipment. Do not try to solder the tubes or open the circuit yourself - this is dangerous to life and breaks the tightness of the system.
How much does diagnostics cost?
In most service centers, a technician’s visit and diagnostics for subsequent repairs are free. Separately, diagnostics can cost from 500 to 1,500 rubles, depending on the region.
When calling a technician, be sure to describe the nature of the sound (crackling, clicking, hum), the conditions under which it appears (constantly, during startup, at night) and the model of your refrigerator. This will help the specialist take the necessary spare parts with him.
Noise prevention and operating rules
In order for your refrigerator to operate quietly and for a long time, it is important to follow simple operating rules. Regular defrosting (even for a No Frost system it is recommended to do this once a year) will help avoid the build-up of excess ice and overload the system.
Keep the condenser (grid at the back) clean. Dust and animal hair collected between the coils impair heat transfer, causing the compressor to work harder and longer, which increases wear and noise. You need to clean it with a soft brush or vacuum cleaner every six months.
Correct installation also plays a role. The refrigerator must be placed on a flat, hard surface. Use a spirit level to adjust the legs. An unstable position increases vibration and contributes to the appearance of extraneous sounds.
- 🧹 Regularly vacuum the rear radiator grille.
- ❄️ Do not load warm products into the chamber - this creates unnecessary stress.
- ⚖️ Check the stability of the legs during each general cleaning.
Following these recommendations will extend the life of the unit and maintain silence in your kitchen. Remember that careful attention to the “language” of your equipment helps prevent serious breakdowns.
Frequently asked questions (FAQ)
Why does the refrigerator only crack at night?
At night, the house is usually quieter, so you can hear sounds that were drowned out by household noise during the day. In addition, at night the automatic defrosting cycle is triggered more often, which may be accompanied by cracking ice or expansion of plastic.
Is cracking in a new refrigerator dangerous?
In a new refrigerator, cracking is most often caused by the “grinding in” of parts, thermal expansion of materials or movement of the refrigerant. If there is no burning smell or loss of cold, this is most likely normal. Let the equipment work for several days.
Is it possible to continue to use the refrigerator if it is cracking?
If the crackling is quiet and is not accompanied by other symptoms (heating, smell, lack of cold), you can use it. If the sound is loud, metallic, or accompanied by heating of the case, it is better to turn off the device until the technician arrives.
How to distinguish the crackling sound of a compressor from the crackling sound of ice?
The crackling sound of ice is usually louder, similar to a crackling sound or clicks, and often occurs when turning it on/off. The crackling sound of the compressor is more dull, mechanical, often accompanied by strong vibration of the housing and comes from the bottom of the unit.