A sudden foreign sound in kitchen appliances can unsettle any owner. The refrigerator makes cracking and clicking noises for many reasons, and not all of them indicate a serious breakdown. Often frightening sounds are a consequence of natural physical processes occurring inside the unit during its normal operation.
However, a sharp change in the acoustic background cannot be ignored either. If a previously quiet one begins to make loud knocks, and a crackling sound is regularly heard inside the camera, this may indicate wear of parts or a violation of operating conditions. Understanding the nature of sound is the first step to solving the problem, which will help you avoid expensive repairs or, conversely, call a technician in time. compressor began to make loud knocks, and a crackling sound is regularly heard inside the camera, this may indicate wear of parts or a violation of operating conditions. Understanding the nature of sound is the first step to solving the problem, which will help you avoid expensive repairs or, conversely, call a technician in time.
In this article we will analyze in detail the mechanical, electrical and thermal causes of noise. You will learn to distinguish between normal response system operation and signs of a critical problem that requires immediate attention. Correct diagnosis by ear will save you time and nerves.
Natural processes: thermal expansion of materials
The most common and absolutely harmless cause of crackling is physics. The internal walls of the refrigerator compartment, shelves and even the body itself are made of plastic or metal. When there is a sudden change in temperature, for example, after turning on the compressor or loading warm products, the materials change their volume.
This process is called thermal expansion. Plastic contracts or expands faster than metal parts, causing the parts to rub against each other. It is this friction that our hearing perceives as a characteristic crack or click, reminiscent of the sound of a bursting bubble.
Usually such sounds are most intense in the first hours after defrosting or initially turning on the equipment. Over time, when the temperature stabilizes, the frequency of clicks should decrease. If the cracking becomes constant and is accompanied by a hum, it is worth checking the installation of the unit.
It is important to note that in models with the system No Frost there are more plastic elements than in drip-type ones refrigerators. Therefore, owners of such equipment often hear crackling sounds. This is a design feature, not a defect.
Operation of the thermostat and defrost system
The second most common source of clicking noises is the electrical components of the temperature control system. The thermostat (thermostat) is responsible for maintaining the set mode. When the temperature in the chamber rises above the set temperature, the contacts close, starting the compressor. This process is accompanied by a loud, distinct click.
A similar sound is produced by start relaylocated next to the motor. It provides an impulse to start the engine. If the refrigerator clicks and does not turn on, the problem may lie in the start relay or the compressor itself. However, a single click every 20-40 minutes is a sign of proper operation of the automation.
In units with automatic defrosting, a timer or electronic module is responsible for defrosting the evaporator. Switching between “cooling” and “defrosting” modes is also accompanied by a characteristic sound of contact switching. In modern models with inverter motors, this process is quieter, but in classic systems it is clearly audible.
⚠️ Attention: If the thermostat clicks become too frequent (every 2-3 minutes) and the refrigerator does not have time to get cold, the temperature sensor may have failed or a freon leak has occurred. Diagnostics required.
Problems with the compressor and start relay
The compressor is the heart of the refrigerator, and its operation is not always silent. If you hear not just a click, but a series of rapid knocking sounds, followed by a humming sound and then dying out, this is a warning sign. This picture often indicates an attempt to start the engine, which fails due to a malfunction.
Most often the culprit is starting relay. This is a small part that fits onto the compressor rod. Inside it is a coil and contacts. Over time, the plastic of the relay case dries out and the contacts burn, which causes cracking and sparking. Replacing this part is an inexpensive and quick repair.
A more serious situation arises when the compressor itself begins to “knock.” This could mean wear on internal mechanical components, valves, or the piston group. If the motor operates with a metallic clang and strong vibration, its resource is coming to an end.
You can diagnose the problem by listening to the nature of the sound:
- 🔨 A loud single click and the motor starting is the norm.
- ⚡ A series of frequent clicks and no buzzing start - a malfunction of the relay or starting winding.
- 📉 A steady hum with a metallic tinkling sound - wear on the compressor suspension.
Why does an old refrigerator hum?
With age, the rubber shock absorbers on which the motor-compressor is suspended become dull and lose elasticity. As a result, vibration is transmitted to the metal housing, increasing the noise. Replacing shock absorbers solves the problem.
Fan and No Frost system
Refrigerators operating using technology No Frostare equipped with fans for air circulation. These devices ensure the absence of ice, but contribute to the acoustic background. If the fan begins to make cracking, grinding or intermittent clicking noises, this indicates a mechanical problem.
The most common cause is ice. If the defrost system does not work correctly, ice will build up on the blades or walls of the duct. The rotating fan touches the ice crust, making a cracking sound. In this case, complete defrosting of the refrigerator is required (for 10-12 hours with the power turned off).
Another reason is wear of the fan motor bearings. Over time, the lubricant dries out and the axle begins to rotate with difficulty, making noise. Also, the blades could move and touch the walls of the plastic box.
To eliminate the problem, disassembling the back wall of the freezer or refrigerator is often required. You should only climb there yourself if you have the skills, as it is easy to damage the fragile plastic or spoil the seals.
Vibration of the case and incorrect installation
Sometimes the source of noise is not inside at all, but outside. If the refrigerator is not installed level, its body may warp. This leads to the fact that the door does not fit tightly, and the unit itself vibrates when the motor is running, transmitting the hum to the floor and walls.
Check the installation level. To do this, use a building level or a simple glass of water. Height adjustment is carried out using the front support legs. They must be unscrewed so that the refrigerator is stable and the door closes itself when opened 45 degrees.
Also check the distance to the walls and furniture. If the case touches a cabinet or wall, vibration will increase. The minimum gap should be 5-7 cm. In addition, bottles or dishes often rattle inside the chambers, touching each other from the vibration of the shelves.
☑️ Noise diagnostics
Table: Diagnostics by sound type
To To make it easier for you to navigate the nature of the noise, we have compiled a summary table of the main symptoms and their probable causes. This will help you make a decision: call a specialist or act independently.
| Sound type | Probable cause | Degree of danger | Actions |
|---|---|---|---|
| Single click | Thermostat activation | Normal | Do nothing |
| Crackling inside the chamber | Thermal expansion of plastic | Normal | Observe |
| Frequent clicks and buzzing | Malfunction of the starting relay | High | Call a repairman |
| Rattling and crackling | Ice on the fan | Medium | Defreeze |
| Metal knock | Compressor wear | Critical | Motor replacement |
⚠️ Attention: If you smell burnt conductivity or plastic at the same time as clicks appear, Unplug the refrigerator immediately! This may be a sign of a short circuit or overheating of the contacts.
When urgent repairs are needed
Not all sounds require calling a specialist, but there are situations when delay can lead to complete breakdown of the unit. If the refrigerator clicks but does not start, and at the same time it is warm inside, this is a direct signal of a malfunction starting relay or compressor.
You should also be wary if clicks are accompanied by blinking indicators on the control panel (in electronic models). This indicates an error in the self-diagnosis system. The error code can be found in the instructions, which will help the technician quickly identify the breakdown unit.
Attempts to independently repair the electrical part without the appropriate qualifications are dangerous. High voltage and presence of refrigerant require a professional approach. It is better to call a specialist for an accurate diagnosis than to risk safety.
Noise prevention and proper care
So that the refrigerator can serve for a long time and quietly, after it need to be looked after properly. Regular defrosting (even for systems No Frost it is recommended to do this once a year) will prevent the formation of ice jams in the fans and drainage.
Keep the condenser grid at the back of the refrigerator clean. Dust and animal hair impair heat transfer, causing the compressor to work longer and harder, which increases wear and noise. The grille should be cleaned with a vacuum cleaner or a soft brush.
Do not overload the shelves and ensure that food does not touch the back wall of the chamber. This will not only reduce the noise level from vibration, but will also ensure proper air circulation, which is important for the safety of food.
Does fullness affect noise?
Yes, an empty refrigerator can “make noise” more due to the resonance of the internal shelves. Full bottles and products act as additional sound insulators, dampening vibration.
Frequently asked questions (FAQ)
Is it normal for a new refrigerator to make noise in the first days?
Yes, this is absolutely normal. New materials, especially plastic internal lining, must undergo a process of “grinding in” and adaptation to temperature changes. After 3-5 days, the intensity of the sounds should decrease.
Why does the refrigerator click but does not freeze?
Most likely, the compressor start relay or the motor itself has failed. The mechanism tries to start (clicking), but cannot turn the shaft. The relay needs to be replaced or the compressor repaired.
Can a broken shelf crack?
Yes, cracked glass or plastic under load can make sounds similar to shots or crackling, especially when the temperature changes. Check the integrity of all glass elements.
How often should the thermostat click?
Depending on the load and room temperature, the thermostat can operate from 2 to 8 times per hour. If clicks occur every minute, this is a sign of a sensor malfunction or a freon leak.