A sudden knock in the refrigerator can disturb the peace of any owner of household appliances. The situation when Something slams in the refrigeratoroften causes panic, because it seems that the unit is about to fail. However, this sound does not always indicate a critical breakdown that requires expensive intervention.
Extraneous noises can arise due to natural physical processes, such as the expansion of materials, or indicate a malfunction of compressor and the start relay. To understand the nature of the sound, you need to listen carefully to the nature of the clap and the frequency of its occurrence. In this article, we will look at the main causes of knocking and methods for eliminating them.
Understanding the operating principles of your model will help you quickly determine whether you need to call a technician or whether the problem can be solved yourself. Often the cause is a simple violation of operating rules or an unstable position of the housing. Let's figure out why your equipment started making strange sounds.
Physical reasons: thermal expansion of materials
The most common and safest reason for popping noises is thermal expansion. Internal plastic elements, such as shelves, boxes and the back wall, may become deformed due to sudden temperature changes. This process is accompanied by a characteristic crackling sound or clicks reminiscent of gunshots.
Usually such sounds occur immediately after turning on the refrigerator or after loading a large amount of warm food into the chamber. The materials from which it is made internal housinghave different coefficients of expansion, which leads to friction and the subsequent sound effect. This is absolutely normal for many models, especially with the system No Frost.
⚠️ Attention: If popping sounds are accompanied by the appearance of condensation on the walls or a change in temperature inside the chambers, then the matter is not in physics, but in a violation of tightness or defrost operation.
The frequency of such claps may vary. Sometimes they happen once an hour, and sometimes in series. It is important to note that this effect may be more pronounced in newer refrigerator models due to the use of modern, more rigid types of plastic. Over time, when the equipment “gets used to”, the sounds may become quieter.
To reduce the noise level from thermal expansion, you can check the tightness of all internal elements. Sometimes it is enough to simply adjust shelf or the glass insert so that they do not come into contact with the walls too tightly. This simple action often eliminates the resonating effect.
Operation of the defrost system and compressor
If you hear a loud bang when the refrigerator goes silent after a long period of operation, most likely the thermal relay is tripping or ice is being dumped. In systems No Frost periodic defrosting of the evaporator is a standard procedure. Ice accumulated on the radiator melts and can fall into the pan with a crash, creating a crashing sound.
The compressor is the heart of the refrigeration unit. When it starts or stops, a surge in refrigerant pressure occurs in the pipelines. This process is often accompanied by a sound similar to a blow or thud. If motor-compressor works smoothly, and cotton sounds once at the beginning or end of the cycle, there is no need to worry.
How does the defrost cycle work?
In refrigerators with the No Frost system, the heating element is turned on several times a day, which melts the ice evaporator Water flows into the tray, and pieces of ice may fall with a characteristic sound. This is a normal operating process and does not require intervention.
However, if the popping sounds become metallic and are repeated frequently, this may indicate problems with the start relay. An old relay may click when trying to start the engine, but may not be able to do the job. In this case, the motor may hum, and then there is a sharp click of the protection being turned off. This already requires replacing the part.
It is important to distinguish between the rhythmic sounds of a working unit and chaotic impacts. The normal operation of the cooling system is predictable. If refrigerator starts to “shoot” without reference to the switching cycles, it is worth checking the condition of the tubes and fasteners.
Problems with the fan in No Frost chambers
In models with automatic defrosting, the fan is responsible for air circulation. If Something slams in the refrigerator rhythmic and frequent, especially in the freezer, the source of noise may lie there. The fan blades may touch ice or a foreign object.
Ice on the blades is a common problem when the door seal is broken or the defrost sensor is faulty. The ice builds up unevenly, and when the fan rotates, it begins to hit the walls of the channel. This creates a loud crash, which can easily be confused with a compressor breakdown.
- 🌀 Frozen fan bearing - causes humming and periodic knocking when trying to rotate.
- 🧊 Ice buildup on the blades - leads to imbalance and impacts on the duct housing.
- 🔌 A loose motor mount causes vibration and knocking of the entire structure against the chamber wall.
For diagnostics, you need to defrost the refrigerator for 24 hours. If after complete defrosting the sound disappears, then the problem was in the ice. If the noise remains, you will need to disassemble the rear panel of the freezer and check the condition of the fan.
☑️ Fan diagnostics
Sometimes the cause is a manufacturing defect or a displacement of the fan axis. In such cases, even without ice, beating will be observed. Replacing a fan is a simple procedure, but it requires care when removing plastic latches and panels.
Improper installation and vibration of the case
Often the answer to the question of why the refrigerator slams lies in its incorrect location. If the unit is not level, vibration from the operating compressor is transmitted to the floor and intensified. The housing may periodically move and return to place with a dull thud.
Check the adjusting feet. They should be unscrewed so that the refrigerator is stable and the doors close on their own with a slight push. A loose fit of the legs to the floor creates voids in which sound travels, amplifying any mechanical knock.
| Symptom | Possible cause | Elimination method |
|---|---|---|
| Thud knocking at the bottom | Touching of the tubes on the body | Move the tubes away by hand (when turned off!) |
| Rattling during operation | Unstable legs | Adjusting the height of the supports |
| Resonance of walls | Proximity to furniture | Move the refrigerator 5-10 cm |
| Sound of breaking glass | Poor shelf position | Adjust the glass insert |
You should also pay attention to the distance to the walls and furniture. If the refrigerator is placed close to each other, it can transmit vibrations to the cabinet or wall, which in turn will resonate and make popping sounds. It is enough to move the equipment a few centimeters.
Check the contents of the refrigerator itself. Bottles or cans on a shelf may touch each other. When the compressor vibrates, they begin to knock against each other, creating the illusion of a breakdown inside the unit. Remove unnecessary items and check the silence.
Mechanical damage and wear of parts
If physical processes and installation problems are excluded, it is worth considering the possibility of mechanical failure. Pipes leading to the compressor may, over time, lose their elasticity and begin to vibrate, hitting the metal housing or each other.
Start relay is another candidate for replacement. On older models, it may make a loud clicking sound every time it starts. If the relay is faulty, it may click repeatedly while trying to start the engine, which sounds like continuous gunfire. This is dangerous for the compressor.
⚠️ Attention: If you hear a series of relay clicks and the refrigerator does not turn on and does not cool, immediately unplug it. Continuing to operate in this mode will lead to burnout of the motor winding.
Wear of the compressor suspension shock absorbers also leads to knocking noises. The motor hangs on springs, and if one of them bursts or stretches, strong vibration and impacts against the walls of the casing will be felt during operation. In this case, you need to call a technician to replace the shock absorbers.
In rare cases, the cause may be damage to the inner lining or peeling of the thermal insulation. A piece of foam or plastic, having come off, can fall into the fan operating area or simply roll along the bottom, making strange sounds when the door is opened.
When you need to call a technician
Independent diagnostics have their limits. If you have checked all available nodes, but Something pops in the refrigerator with increasing strength, it is better not to risk it. Sounds accompanied by a burning smell, smoke, or complete cessation of cooling are especially alarming.
A technician is needed if a compressor replacement, repair of the freon circulation system, or complex troubleshooting of electronics is required. These jobs require special tools, a vacuum pump and soldering skills. Trying to do this yourself can completely damage the equipment.
Also, professional help is needed if the refrigerator is under warranty. Any independent opening of the seals on the compressor or violation of the integrity of the circuit automatically voids the warranty. In this case, it is better to immediately contact an authorized service center.
Prevention of noisy operation
In order for your refrigerator to operate quietly and for a long time, it is important to follow simple operating rules. Regular defrosting (for models without No Frost) and cleaning the condenser from behind will help avoid compressor overloads, which often cause knocking.
Monitor the condition of the door seals. If they are worn out or dirty, warm air enters the chamber, causing the unit to work harder. Frequent turning on and off of the motor accelerates the wear of the starting relay and shock absorbers.
⚠️ Attention: Do not install the refrigerator near heat sources (stove, radiator) or in direct sunlight. Overheating causes the compressor to work to the limit, increasing noise levels and the risk of breakdowns.
Periodically check the stability of the legs and the absence of foreign objects behind the rear grille. Dust and animal hair that accumulate there impair heat transfer, which also affects acoustic comfort. Simple vacuuming every six months will extend the life of the equipment.
Why does the refrigerator slam only at night?
At night, extraneous noises in the apartment subside, and operating equipment becomes more noticeable. In addition, the room temperature is often lower at night, which may slightly change the thermostat settings. It is also possible that during the day the sound is masked by household noise, and at night every click of the relay is heard.
Is it dangerous if the clap was made once and does not happen again?
A single clap is most likely caused by thermal expansion of the plastic or a single voltage surge in the network, which caused the relay to operate a little louder. If the cooling persists and there are no other symptoms, there is no danger. Just watch the equipment.
Can a new refrigerator knock?
Yes, new equipment can make sounds. The plastic has not yet “got used to it”; the compressor can operate in run-in mode. Typically, after 1-2 weeks of use, background noise decreases. If the knocking is very loud and interferes with sleep, check the level setting.