Unexpected loud sounds emanating from refrigerator compartment, can scare any owner of household appliances. The situation when the refrigerator is shooting something similar to a shot or a loud crack often causes panic and thoughts of an imminent breakdown of an expensive unit. However, these sounds do not always indicate a critical malfunction that requires immediate intervention from a technician.
In most cases, sharp clicks or pops are caused by physical processes occurring inside the cooling system, or by the characteristics of the case materials. Understanding the nature of these sounds will help you distinguish normal operation of the device from a real breakdown that requires replacement of components. Let's figure out exactly what mechanisms can produce such frightening signals.
Thermal expansion of housing and evaporator materials
The most common and absolutely safe cause of loud sounds is a physical phenomenon known as thermal expansion. The interior walls of the refrigerator, the plastic shelves and, most importantly, the evaporator tubes are constantly subject to cyclic temperature changes. When the compressor turns on, the temperature drops and the materials compress, and when the engine stops, they heat up and expand.
It is at moments of a sharp change in temperature that the same sound is heard, reminiscent of a shot or the cracking of branches in a fire. This happens especially often in models with a system No Frost, where temperature changes are sharper due to the active operation of fans and defrost heating elements. The plastic from which the internal panels are made has a high coefficient of expansion, therefore crackling of plastic this is a normal situation.
⚠️ Attention: If sounds appear strictly at the moments when the motor is turned on or off, as well as during the automatic defrosting cycle, then this is a normal physical reaction of materials, and not breakdown.
The intensity of such sounds may depend on the quality of the build and the rigidity of the materials used. In some budget models, thin plastic panels can resonate more strongly, creating a “shooting” effect. Over time, when the plastic “gets used” to constant cycles of freezing and defrosting, the frequency of such pops usually decreases.
Operation of the compressor and start relay
The second most frequent source sharp sounds - this is the engine of the refrigeration unit itself. When the compressor starts, a sharp voltage surge occurs in its electrical circuit, which activates the start relay. This electromagnetic mechanism produces a characteristic click, which can seem very loud in the silence of the night.
If you hear not just a click, but a series of quick pops when you try to start, followed by silence, this may indicate a problem with the start protection relay or the motor itself. In such cases compressor tries to start, but the protective mechanism resets the circuit due to overload or faulty windings.
- 🔊 A single loud click at start is the norm for most models.
- 🔊 A series of clicks without starting the motor - a sign of a malfunction of the relay or compressor.
- 🔊 A hum that turns into a pop is a possible water hammer in the system.
It is also worth considering that modern inverter compressors work differently than older linear models. They do not make sharp sounds when starting, as they gradually gain momentum. If your inverter refrigerator started to make sounds similar to blows, this is a reason to pay attention to the vibration of the housing or motor mount.
The influence of the No Frost system and defrosting
Refrigerators equipped with an automatic defrosting system No Frost, have a more complex design, which gives rise to an additional range of sounds. In these models, the heating element (heating element) is periodically turned on, which melts the ice on the evaporator. Contact of hot water with cold metal elements or ice can cause sudden steam formation and characteristic sounds similar to hissing or light explosions.
In addition, such units operate fans that circulate cold air. If ice forms on the fan blades or a foreign object gets there, a cracking or knocking noise may occur, which can easily be confused with a gunshot. This happens especially often if the food is too close to the back wall.
It is important to distinguish between the sounds of a running fan and the sounds of defrosting. A cyclic hum, interrupted by clicks, usually indicates normal operation of the system. However, if the sound is accompanied by a cessation of cooling, it is necessary to check the condition of the evaporator drainage system.
Why is No Frost louder?
In refrigerators with the No Frost system there are more plastic parts and air channels that resonate and expand more actively than in simple models with drip system.
Mechanical causes and vibration
Sometimes the reason for “shots” lies not in internal processes, but in external influences or improper installation. Vibration from a running compressor is transmitted to the housing and can cause loose parts to move. Condenser tubes located at the rear of the unit may touch each other or the cabinet wall, creating a metallic clanging sound.
Check that the refrigerator is stable on the floor. If the feet are not adjusted and the body is wobbly, any vibration from the engine will be amplified. It is also worth inspecting the space around the refrigerator: nearby furniture or dishes on the top shelf can resonate and fall, creating noise.
Pay special attention to the shipping bolts if the refrigerator is new. Although there are fewer of them in refrigerators than in washing machines, some compressor fastening elements may become fixed during transportation and require removal or checking for tightness.
☑️ Vibration diagnostics
Comparative table of noise sources
For ease of diagnosis, we suggest that you familiarize yourself with the table that will help classify the sounds you hear and determine their probable reason. This will allow you to quickly determine whether a specialist’s help is needed.
| Sound type | Probable cause | Danger | Actions |
|---|---|---|---|
| Loud crackling/popping | Thermal expansion of plastic | Safe | Observation |
| Click at start | Operation of the starting relay | Normal | No action |
| Series of clicks | Relay/compressor malfunction | High | Call the technician |
| Metal clanging | Pipe vibration | Medium | Adjust the pipes |
| Hissing and gurgling | Movement refrigerant | Normal | No action |
When analyzing the table data, remember that the combination of sounds can be individual for each model. For example, some refrigerators Indesit or Atlant are designed with louder clicks of the thermostat than in premium brands.
When urgent repairs are needed
Despite the fact that many sounds are safe, there are situations when they should be ignored You can't "shoot" in the refrigerator. If you notice that the refrigerator has stopped freezing along with popping noises, or ice has appeared on the back wall, this is a signal of a malfunction. Also an alarming symptom is a burning smell or a buzzing sound that does not stop.
Frequent turning on and off of the motor (clocking) accompanied by clicking sounds indicates that the compressor cannot reach operating mode. This can lead to its combustion if the starting relay or the engine itself is not replaced in time. In such cases, independent repairs can be dangerous due to high voltage and the presence of refrigerant.
⚠️ Attention: If after a loud bang the refrigerator stops turning on or the light in the chamber goes out when you open the door, immediately unplug the appliance and contact a service center.
Do not try to disassemble the compressor or open the circulation system freon yourself. This requires special equipment and licenses. Your task is to correctly diagnose the symptom and call a qualified specialist if the sounds are no longer just background noise.
Frequently asked questions (FAQ)
Why does the refrigerator only slam loudly? at night?
At night, the overall noise level in the apartment decreases, and the sounds of equipment operation become more noticeable. In addition, at night, voltage drops in the network occur more often, which can affect the operation of the relay, or a moment of cyclic defrosting simply occurs, which you might not have heard during the day.
Can a glass shelf burst from sound?
The sound wave itself from the clap of plastic or a relay is not capable of breaking glass. However, if the shelf is poorly installed or has microcracks, strong vibration of the housing during compressor operation can become a catalyst for destruction. Check the reliability of the installation of the shelves.
Does the new refrigerator shoot more often than the old one?
Yes, new materials, especially the plastic of the internal chambers, undergo active shrinkage and adaptation to temperature conditions during the first time of operation. After 2-4 weeks, the intensity of the sounds usually decreases. If this does not happen, check the installation.
Is it dangerous to ignore relay clicks?
Single clicks are not dangerous. But if the relay clicks repeatedly, trying to start the engine, this can lead to overheating of the compressor windings and failure. In this case, the problem cannot be ignored.