A sudden loud sound, reminiscent of a gunshot or a crackling sound, coming from a working refrigerator can scare any owner. Often this frightening sound occurs in the silence of the night or when you are near equipment. A panicky thought immediately arises that expensive equipment has broken down or, worse, is about to explode. However, in the vast majority of cases, this acoustic effect is a normal physical processassociated with the design features of modern units.
A refrigerator is a complex mechanism where temperature changes, refrigerant movement and the operation of electrical circuits constantly occur. The materials of the housing, internal plastic and metal tubes have different coefficients of expansion. It is the inconsistency of these processes that most often gives rise to the sounds that we perceive as “shots.” Understanding the nature of these noises will help you distinguish normal operation from a real breakdown that requires the intervention of a technician.
In this article we will analyze in detail all the possible reasons why the refrigerator shoots, from harmless expansion of the plastic to problems with the start relay. We'll look at the differences in behavior between different defrosting systems and explain when you should worry and when you can sleep on. It is important to listen carefully to the nature of the sound in order to correctly diagnose the condition of your equipment.
Physics of the process: thermal expansion of materials
The most common and absolutely safe reason why a refrigerator makes clicking or even popping sounds is thermal expansion. The inner walls of the chamber, shelves and back panel are made of plastic, which contracts when cooled and expands when heated (during idle time or defrosting). This process does not happen smoothly and silently; plastic can suddenly change its geometry, producing a loud crack, very similar to a gunshot.
Such sounds are especially common in new refrigerators or after long periods of inactivity. When the unit first reaches temperature, or when the No Frost system enters defrost mode, the temperature difference inside the chamber can reach tens of degrees. At this moment ABS plastic other polymers experience stress, which leads to a characteristic sound. As a rule, these sounds are not repeated often and subside after the temperature has stabilized.
⚠️ Attention: If the crackling sound is heard with alarming frequency (every few minutes) and is accompanied by deflection of the chamber walls, this may indicate a defective case or a violation of the assembly technology, which requires contacting service.
It is also worth considering that different parts of the refrigerator heat up and cool down at different rates. A metal evaporator hidden behind a plastic panel can expand faster than the plastic itself, causing friction and a subsequent sharp sliding sound. This phenomenon is especially typical for models with a system No Frostwhere the cooling and defrosting cycles alternate automatically.
Operation of the No Frost and defrosting system
If your refrigerator is equipped with an automatic defrosting system, then periodic clicks and pops for it are a sign of proper operation. Unlike old models with a crying evaporator, here TEN (thermoelectric heater)is responsible for the defrosting process. When the timer or electronic module commands the start of the defrost cycle, voltage is applied to the heater and it begins to heat up sharply.
At this point, several things can happen that cause noise. Firstly, when heated, the heating element itself can make a sound similar to the operation of an electric stove, but sometimes this is accompanied by a short click. Secondly, the ice that has accumulated on the evaporator begins to actively crack and chip off when suddenly heated. Pieces of ice falling onto the heater or into the tray can create sounds that can easily be confused with a shot inside the chamber.
In addition, the No Frost system uses a fan. If ice has frozen on the fan blades or the axle, a characteristic cracking or knocking noise may be heard when the engine starts. This happens until the ice crumbles or melts. Regular maintenance and checking of the drainage system helps to avoid excessive accumulation of ice, which becomes a source of noise.
Why does the ice crack so loudly?
The ice crust that grows on the evaporator is a monolithic structure. When the heating element is sharply heated, the internal tension in the ice structure increases faster than it has time to melt. At some point, the bonds are broken and the ice breaks. In the closed volume of the chamber, this sound is amplified, creating a popping effect.
Start relay and electrical clicks
If the sound you hear is more like a clear, ringing click, repeated with a certain periodicity or when the compressor is turned on/off, then we are talking about electrics. Responsible for starting the refrigerator engine starting relay. This device applies a pulse to the compressor winding to start it and then turns off. Mechanical switching of contacts inside the relay is always accompanied by an audible click.
In normal operation, this sound is quiet and barely noticeable against the background of the hum of the motor. However, if the relay is worn out, the contacts may burn or stick, resulting in louder, more harsh sounds. Sometimes the relay can “shoot” several times in a row, trying to start the compressor if the starting torque is insufficient or there are problems with the motor windings.
Also, the source of electrical clicks can be thermostat (in mechanical models) or an electronic control module. When the set temperature is reached, the contacts open, breaking the circuit, which is accompanied by a click. If this sound has become too loud, it is worth checking the tightness of the contacts or the condition of the regulator itself.
Below is a table that helps differentiate the types of clicks:
| Sound type | Probable cause | Danger | Action |
|---|---|---|---|
| Deaf clap | Plastic expansion | No | Observation |
| Sound click | Relay or thermostat | Low | Frequency check |
| Ice cracking | Defrost cycle | No | Norm for No Frost |
| Series of clicks | Start attempt | High | Call the technician |
Problems with the compressor: when it stops worry
The compressor is the heart of the refrigerator, and its operation is normally accompanied by a smooth, low hum. However, if you hear sharp knocks, grinding noises, or loud popping noises coming directly from the motor (usually at the lower rear of the unit), this is a warning sign. One of the reasons may be hydraulic hammer in the system, caused by liquid freon entering the compressor cylinder instead of gaseous.
Worn out valves inside the compressor can also make loud sounds. When operating under high pressure, valves must open and close quietly and tightly. If the valve group is damaged or worn, gas may flow with a characteristic whistle or pop. In the long term, this leads to a drop in performance and eventual failure of the unit.
⚠️ Attention: If the compressor makes a series of loud clicks, after which it goes silent, and this repeats several times, immediately unplug the refrigerator. This is a sign that the starting relay cannot start the engine, and the compressor is overheating, which can lead to its combustion.
Another rare but possible cause of “shots” is a rupture of the internal partition in the condenser or evaporator due to corrosion or a manufacturing defect, although more often this simply leads to a gas leak and silence (stopping work). But at the moment of rupture, a pop may be heard.
The influence of improper installation and loading
Sometimes the cause of strange sounds lies not in internal processes, but in external factors. If the refrigerator is not installed level, vibration from the operating compressor is transmitted to the housing and intensified. At some point, the vibration may reach a resonance, and some part (for example, a plastic decorative panel on the back or an egg tray) will suddenly move, making a loud sound.
Check whether your unit is stable. Rock it from side to side. If it wobbles, you need to adjust the height of the front supports. Also make sure that the refrigerator does not touch the wall or furniture, since during operation the case may vibrate slightly and hit obstacles.
The second important aspect is loading chambers. If you put a hot pan in the refrigerator or fill the freezer too tightly with food, air circulation is disrupted. This creates additional load on the compressor, forcing it to work in extreme mode. Overheating and sudden changes in pressure in the system under such conditions can provoke non-standard sounds.
☑️ Diagnosis of external causes of noise
Rare cases: microcracks and leaks
There is a scenario that is really related to a “shot” in the literal sense, albeit in miniature. If a microcrack has formed in the refrigerant circulation system (for example, due to corrosion of an aluminum evaporator or mechanical damage during defrosting with a knife), gas under pressure may begin to escape. At the moment of breakdown, a sharp bang may be heard, similar to a cork being shot.
After such an event, the refrigerator, as a rule, stops freezing. You may hear a hissing sound if you bring your ear close to the injury. This is a critical situation that requires professional repairs: searching for leaks, sealing the hole and filling the system with freon.
It is also worth mentioning the explosion hazard of some old-type refrigerants or propane-butane mixtures used in modern environmentally friendly models (R600a). Although the likelihood of a household refrigerator exploding under normal conditions is negligible and requires a spark + gas concentration, theoretically, if there is a strong leak and there is a fire source, such a risk exists. This is why manufacturers prohibit the use of open flames when defrosting.
FAQ: Frequently asked questions
Why does the refrigerator click even when it is unplugged?
If the refrigerator is turned off, but there are still residual cold or heat inside, The processes of thermal expansion of plastic and metal continue. The plastic contracts or expands, producing characteristic sounds. This is normal and will stop when the temperature inside and outside are equal.
Is it dangerous if the refrigerator slams loudly once?
A single bang is most often harmless and is caused by bursting ice or sudden expansion of plastic. A series of pops or clicks is dangerous, especially if they are accompanied by a cessation of cooling or a burning smell.
Can gas explode in a refrigerator?
In modern living conditions this is almost impossible. The refrigerants are in a closed circuit. Even if there is a leak, the concentration of gas in a large kitchen is insufficient to cause an explosion without a powerful ignition source. However, ventilating the room if you suspect a leak will not hurt.
A new refrigerator is cracking and clicking - is this a defect?
No, this is typical for a new refrigerator. There is a “grinding in” of parts, the release of residual gases from the system (if these are the first hours of operation) and the active expansion of new materials. Usually, after 2-3 days of operation, the sounds become quieter or disappear.
What to do if the clicks become more frequent?
If the nature of the sounds has changed, they have become louder or the frequency of their occurrence has increased, carry out diagnostics: check the stability, the absence of ice on the fan and the operation of the compressor. If there are no visual problems, but the sound bothers you, call a technician to diagnose the electrical part.