The situation when the refrigerator is making a lot of noisecan unsettle any owner, especially if before this the unit worked quietly and unnoticeably. Extraneous sounds often signal the beginning of destructive processes inside the mechanism, which, if ignored, can lead to expensive overhauls or complete replacement of the equipment. Loud crackling, clicking or characteristic humming requires immediate attention and correct diagnosis to prevent failure of important system components.
In this article we will analyze in detail the main causes of noise, from harmless plastic expansion to critical compressor breakdowns. You will learn to distinguish between types of sounds, understand when you can fix the problem yourself, and in which cases you need to call a specialist. It is important not to panic, but to consistently analyze the nature of the noise and the conditions for its occurrence.
It is important to understand that modern models of refrigerators, such as Bosch or Liebherr, are equipped with complex No Frost cooling systems that make specific sounds during operation. However, even for them, a sharp, loud crack is not the norm and requires intervention. Let's figure out what exactly is happening inside your equipment.
Natural causes of crackling noises during operation
Loud sounds do not always indicate a breakdown. Often crackling in the refrigerator is a consequence of natural physical processes occurring inside the body. The main culprit here is thermal expansion and contraction of materials. The internal plastic, shelves and even the metal case shrink when cooled, and expand when thawed or the heating elements are turned on. This process is accompanied by characteristic clicks, which can be quite loud in silence.
Such sounds are especially often produced by new units or models that have just been defrosted. The plastic has not yet “settled” completely, and temperature changes cause its deformation. It can also be a source of noise defrost cycle in No Frost systems. At this moment, the heating element (heating element) turns on, and the ice crust on the evaporator begins to actively crack and break off, falling into the pan. This sound may resemble gunshots or a loud crack.
If your refrigerator makes sounds exclusively when the motor is turned on or off, as well as during cyclic defrosting, most likely, from a technical point of view, it is working. However, it is worth listening: if the crackling sound is accompanied by vibration of the case or humming, the problem may lie in incorrect installation.
⚠️ Attention: If the crackling sound occurs strictly every 30-40 minutes and lasts for several seconds, accompanied by the sound of dripping water, this is the normal operation of the No Frost system. But if the sound has become sharper, louder or its tone has changed, a check is required.
Problems with the compressor and start relay
When the refrigerator is cracking in the area of the motor-compressor located at the bottom rear, this often indicates mechanical or electrical main engine malfunction. The compressor is the heart of the refrigerator, and any extraneous sounds here require special attention. One of the common causes of rattling noise is wear or breakage of the start relay. This small element is responsible for starting the engine, and if it malfunctions, the contacts can spark and make loud clicks, and the compressor itself can hum and twitch, trying to start.
Another reason is hydraulic hammer. If oil or liquid freon gets into the refrigerant system, the piston group experiences enormous load upon startup. This is accompanied by a sharp, strong crack or impact. In the long term, this can lead to broken pipes or seized pistons. Also, a cracking noise can be produced by itself motor-compressor when the service life of bearings or internal bushings is exhausted.
In old models, for example, Soviet ones ZIL or Biryusa, sounds like these could be a sign of wear and tear that has been lived with for years. Modern inverter compressors operate almost silently, and any knock for them is a sign of a serious electronic or mechanical malfunction.
How to check the start relay yourself?
To check the relay, you need to disconnect the refrigerator from the network, remove back cover and remove the relay from the compressor. Shake it: if a ringing sound is heard inside (as if from a broken stone), it means that the piezoelectric element is destroyed and the relay must be replaced. This is a common reason why the refrigerator clicks and does not turn on.
Fan malfunctions in No Frost systems
In refrigerators with a system No Frost the fan is responsible for circulating cold air. If you hear a crackling, buzzing or the sound of rubbing plastic, which intensifies when you open the door (or, conversely, subsides), the problem lies in this particular unit. The fan blades may become iced up, a foreign object may have gotten on them, or the bearings of the motor itself may have worn out.
A situation often occurs when frozen ice blocks the rotation of the blades. In this case, the fan motor begins to hum and crackle, trying to turn the jammed mechanism. This may cause the fan motor winding to burn out. Also, a cracking noise can occur due to the fact that the wiring or plastic clamps inside the chamber come into contact with the blades.
For diagnostics, you need to defrost the refrigerator for 24 hours. If, after complete defrosting and drying, the cracking noise disappears, but a week later it appears again, it means that the defrost cycle is broken (the sensor, timer or heating element is faulty), and the ice is again blocking the fan. If the sound remains immediately after turning on the dry refrigerator, the fan itself will need to be replaced.
| Noise type | Probable cause | Localization | Repair urgency |
|---|---|---|---|
| Rhythmic cracking | Object hit the fan | Freezer compartment | Medium |
| Loud clicking and buzzing | Start relay | Rear, below | High |
| Ice cracking | No Frost system operation | Inside the chamber | Not required |
| Metal clanking | Vibration of tubes | Rear grille | Low |
Influence of ice and disruption of the defrost cycle
Formation of excessive amounts of ice is the scourge of systems No Frost. If the defrost cycle is disrupted, ice begins to accumulate not only on the hidden evaporator, but also penetrate into other components. When the ice mass becomes too large, it can begin to crack under its own weight or under the pressure of a fan. This sound is often described as a “crunching” or “crackling sound of dry snow.”
A critical situation occurs when ice blocks the air supply damper or the fan itself. In this case The refrigerator is very loud., trying to overcome the resistance of the ice plug. This is not only noisy, it is dangerous for the compressor, which begins to work overload, trying to compensate for the lack of air circulation. Ultimately, this leads to an increase in the temperature in the chambers and spoilage of products.
The cause of defrosting failure is often the failure of one of three elements: the defrost heater, the defrost sensor or the timer (electronic control module). Without professional diagnostics with a multimeter, it is difficult to determine which element is faulty. However, the symptoms are usually the same: heavy snow in the freezer and extraneous sounds.
☑️ Symptoms of problems with defrosting
Mechanical damage and vibration of the case
Sometimes the answer to the question “why is the refrigerator cracking” lies not in the internal mechanisms, but in the physical contact of the unit with surrounding objects. Vibration that inevitably occurs during compressor operation can be transmitted to the housing, floor or nearby objects. If the refrigerator is not level, its legs may “walk,” causing distortion and a characteristic crack of metal on metal or plastic.
It is also worth checking the rear grille (condenser). Thin radiator tubes may come into contact with each other or with the housing wall. When the compressor starts, refrigerant under pressure passes through the tubes, causing them to vibrate. If the gap is minimal, rattling and cracking occurs. This can be solved by carefully bending the tubes with your hands (with the refrigerator unplugged!).
Do not forget about external factors. There may be a glass bottle on the shelf inside that resonates with the frequency of the motor. Or the refrigerator itself is too close to the wall or furniture, touching them when vibrating. Checking the perimeter and interior space is the first step before calling a technician.
⚠️ Attention: Before bending the condenser tubes from the back, make sure that the refrigerator is unplugged for at least 30 minutes. The pressure in the system must stabilize and the metal must cool to avoid burns or depressurization of the circuit.
Diagnostics and methods for eliminating noise
To understand why The refrigerator is crackingit is necessary to carry out consistent diagnostics. Start with visual inspection and listening. Open the doors: if the sound changes or disappears, the problem is in the fan or dampers. If the sound remains the same, look for the source behind or below. Try to lightly press on the body or move the unit: if the cracking stops, the problem is vibration or an uneven floor.
If you find that the problem is in the start relay, you can replace it yourself by selecting an analogue according to the markings. This is a relatively inexpensive repair. However, if suspicion falls on the compressor or defrost system, it is better not to risk it. Intervention in the refrigeration circuit requires special equipment (vacuum pump, pressure gauges, freon) and a license.
If the refrigerator is new and under warranty, any independent repair (opening panels, unscrewing seals) will lead to loss of warranty. In such a situation, the only correct solution is to contact the manufacturer’s authorized service center.
Why does the refrigerator crack only at night?
At night, the level of background noise in the apartment is minimal, so even the standard sounds of equipment operation (plastic expansion, freon flow, thermostat clicks) become clearly audible. If you don't notice them during the day, but they seem loud at night, most likely there is nothing wrong with your equipment. This is the effect of silence.
Is it dangerous to continue to operate a cracking refrigerator?
If the cracking is caused by vibration or expansion of materials, it is not dangerous. If the source is a compressor (water hammer, bearing wear) or a fan (icing), then prolonged operation can lead to complete failure of the unit. If the motor becomes very hot or a burning smell appears, operation must be stopped immediately.
Can a new refrigerator make noise?
Yes, new refrigerators often make more noise in the first weeks of operation. The parts are ground in, the heat-insulating foam and plastic shrink. If the sound is not accompanied by a lack of cold or other defects, let the equipment operate for 1-2 weeks in normal mode.
What to do if the crackling intensifies after defrosting?
If after defrosting the crackling intensifies, there may be a lot of moisture left in the system, which has frozen in inappropriate places, or the balance of the refrigerant has been disturbed. The defrost sensor could also be faulty. Leave the refrigerator turned off for 24 hours, then turn it back on. If the problem repeats after a week, call a technician.