A sudden extraneous sound from operating equipment always causes alarm to the owner. Refrigerator is one of the few household appliances that operates non-stop, and any changes in its acoustic profile may indicate a problem. Often, users are faced with a situation when the unit begins to make cracking, clicking or squeaking noises, which is especially noticeable at night.
Understanding the nature of these sounds allows you to diagnose the problem in a timely manner and avoid costly repairs or damage to products. In some cases, cracking is an absolutely normal physical process associated with the expansion of materials, however, loud and intrusive noises should not be ignored. Technology can signal an overload, a malfunction of the start relay, or problems with the condensate drainage system.
In this article we will analyze in detail the mechanical and physical causes of the occurrence cod, and we will also determine when a specialist’s intervention is necessary, and when it is enough to just wait. You will learn to distinguish harmless sounds from critical malfunctions compressor and understand how to properly operate the device to extend its service life.
Physics of the process: thermal expansion of materials
The most common and absolutely harmless cause of cracking is natural thermal expansion and contraction of materials. The internal chamber of the refrigerator, shelves and evaporator (evaporator) are made of plastic and metal, which have different coefficients of thermal expansion. When thermostat turns off the compressor and the temperature begins to rise, or, conversely, drops sharply upon startup, the materials change their volume, making characteristic clicking sounds.
This phenomenon is especially often observed in models with the system No Frostwhere temperature changes are more dramatic due to active air circulation. The crackling noise can occur regularly, approximately every 30-60 minutes, coinciding with the cycles of turning the engine on and off. If the sound resembles the crackling of a fire or the bursting of bubbles, but is not accompanied by vibration of the case, then there is nothing to worry about.
The intensity of such sounds may depend on the quality of the plastic used by the manufacturer. Cheap polymers can deform more, creating a louder acoustic background. Over time, the frequency of such clicks usually decreases, as the internal parts grind against each other.
Malfunctions of the starting relay and electrical part
If a crackling noise is heard immediately when the engine starts or stops and sounds like a loud metallic click or a series of rapid knocks, the problem may lie in the electrical part. Often the source of sound becomes starting relay, which is responsible for starting the engine. If the contacts are worn out or the core is faulty, the relay may make loud clicks while trying to start the compressor.
In more serious cases, a series of clicks indicate an attempt to start the engine when the rotor is locked or the mains voltage is low. If you hear a series of 3-5 clicks, after which the motor hums for several seconds and a click is heard again, followed by a fade-out, this is a sign that the protection has tripped. Compressor in such a situation, the windings are in danger of burning out.
⚠️ Attention: If you observe cyclic clicks every few minutes, and the cold does not build up inside the chamber, immediately unplug the device. Continuing operation in this mode will lead to an expensive replacement of the motor-compressor.
To diagnose this problem, you will need a multimeter and skills in working with electrical circuits. It is necessary to check the resistance of the windings and the integrity of the relay contacts. In modern inverter models, an electronic control unit is responsible for starting, and the characteristic crackling sound of old relays is absent there, electronic signals or a quiet hum.
Problems with the defrosting system and fan
In refrigerators with a system No Frost the fan located in the freezer is responsible for air circulation. If an ice crust grows on the fan blades or on the walls of the air duct, the blades begin to touch the ice, producing a rhythmic crackling sound or noise similar to the operation of a propeller. This is a common problem when there is a malfunction of The defrost heating element or the defrost timer.
Ice can form due to a loosely closed door or a broken seal. Moist air gets inside, settles on the cold elements and freezes, gradually reducing the gap between the blades and the body. As a result, the fan begins to “saw” the ice, creating an unpleasant sound that intensifies when the door is opened (since in many models the fan stops and the cracking stops).
How to check the fan without disassembling?
Open the freezer door and press the button (or magnetic sensor) simulating the door closing. If the fan starts and makes a cracking sound, the problem is in ice or the fan bearing.
To eliminate the problem, it is often necessary to completely defrost the unit within 12-24 hours. If the sound disappears after defrosting and removing the ice, but returns after 1-2 weeks, then the automatic defrost system is not working correctly. It is necessary to check the temperature sensors, heating element and defrost circuit fuse.
Mechanical damage and vibration of the housing
Sometimes a cracking noise occurs due to the fact that the internal elements of the refrigerator come into contact with the housing or with each other during vibration. A running compressor creates microvibrations that are transmitted to the tubes cold pipes. If copper tubes are located too close to the metal casing or plastic parts, they can tap rhythmically, creating a sound similar to cracking.
Objects inside the chambers can also become a source of noise. Glass bottles touching each other or plastic dishes lying on ribbed shelves can make sounds at the slightest vibration. It is recommended to inspect the contents and check whether the food is touching the back wall or ventilation holes.
Another reason is the loosening of the compressor mounting bolts or the legs of the refrigerator. If the unit is not level, the housing may “walk” and creak. Adjusting the level using a spirit level and tightening the front legs often solves the problem of resonant hum and accompanying crackling sound.
☑️ Diagnosis of mechanical noise
Comparative table of sound types
For a more accurate diagnosis, we suggest using the table that will help classify the sound you heard and determine the probable cause.
| Sound type | Probable cause | Degree of danger | Necessary actions |
|---|---|---|---|
| Rare clicks when on/off | Thermal expansion of plastic | Safe | No supervision required |
| Loud cyclic clicks | Starter malfunction relay | High | Disconnect, call a repairman |
| Rhythmic crackling/rustling | Fan touches ice | Medium | Defrosting, checking the heating element |
| Metallic rattling | Vibration of tubes against the body | Low | Move the tubes by hand |
| Crackling with hissing | Freon leak (rare) | Critical | Tightness check |
When a cracking sound indicates a refrigerant leak
One of the most alarming symptoms is a combination of cracking sounds with hissing sounds. If depressurization occurs in the system and freon comes out, this may be accompanied by the characteristic sound of escaping gas. However, more often the leak occurs silently (silently), and the crackling noise in this context may be associated with the operation of the compressor trying to pump a mixture of gas and oil, or with water hammer.
If you hear a hissing, under no circumstances try to look for the leak with an open flame. Refrigerants may be flammable or form toxic compounds when exposed to flame. It is difficult to visually determine a leak; this often requires the use of a soap solution or special leak detectors.
⚠️ Attention: A refrigerant leak not only disables equipment, but can also be hazardous to health in a confined space. If you suspect depressurization, ensure the room is ventilated.
In modern models with with an inverter compressor the control system can diagnose pressure loss by changing the current consumption and shaft speed. In this case, the refrigerator may display an error on the display or flash indicators, signaling the need for service.
Methods of prevention and extension of service life
To minimize the risk of extraneous noise and breakdowns, it is important to follow the operating rules. Regular defrosting (for drip systems) and cleaning the drainage holes prevents the formation of ice plugs, which can cause the fan to crack or prevent air circulation.
Keep the condenser grille at the back of the refrigerator clean. Dust and pet hair sticking to the radiator impair heat transfer. The compressor begins to work harder and longer, overheats, which leads to stronger thermal expansion of the parts and, as a result, a louder crackling sound when cooling.
How often should the condenser be washed?
Ideally - once every 6 months. If you have animals that shed, you should check them quarterly.
It is also important to install the refrigerator correctly. The distance from the back wall to the kitchen wall should be at least 5-10 cm for free air circulation. Failure to comply with this rule leads to overheating and increased noise.
Frequently asked questions (FAQ)
Why does a new refrigerator make loud noises at first? days?
New equipment often makes more sounds during the “break-in” period. The plastic elements of the inner chamber have not yet been subjected to freeze cycles and may react more strongly to temperature changes. In addition, the door seals are still hard and can creak when opened. Usually, after 1-2 weeks of operation, the sounds become quieter.
Is it possible to use a refrigerator if it is cracking?
If the crackling is quiet and resembles the crackling of plastic, operation is possible. If the sounds are loud, metallic, accompanied by relay clicks or humming, it is better to turn off the device until the cause is determined in order to prevent the compressor from failing.
Does the voltage in the network affect the appearance of a crackling sound?
Yes, low or unstable voltage in the network can lead to the fact that the starting relay will not be able to start the compressor normally on the first try. This causes a series of clicking and buzzing noises. In such cases, it is recommended to use a voltage stabilizer.
How to distinguish the sound of a running compressor from a crackling sound?
Normal operation of the compressor is accompanied by a smooth, monotonous hum or buzz. Crackling, clicking, squeaking or sounds of rolling liquid (gurgling) are not the norm for a working unit in stable operation.
Do you need to call a technician if the refrigerator is just cracking?
If you cannot determine the cause yourself (for example, you have excluded touching the tubes and carried out defrosting), it is better to call a specialist. Early diagnosis is often cheaper than replacing a burnt-out motor-compressor.