The appearance of extraneous sounds in kitchen appliances is always a cause for concern, especially when the usual hum is replaced by sharp pops or crackles. Refrigerator is a complex mechanism that operates in a cyclic mode, and some sounds are absolutely normal for its functioning. However, loud clicks may indicate an overload of the engine or problems with thermal expansion of materials.
Owners are often scared when they hear a loud sound, reminiscent of a shot or blow, and immediately look for the service center number. Don't panic ahead of time. In most cases popping they are caused by physical processes occurring inside the chambers or in the refrigerant circulation system. Understanding the nature of sound will help you distinguish normal operation from a serious breakdown.
In this article we will analyze in detail all the possible reasons why your equipment makes strange sounds. We will consider both harmless physical phenomena and technical malfunctions that require the intervention of a specialist. If the cotton is accompanied by a lack of cold or a burning smell, operation must be stopped immediately.
Thermal expansion of housing materials
The most common and absolutely harmless reason for the appearance of popping sounds is thermal expansion and contraction materials. The inner walls of the chamber and the outer casing are made of plastic and metal, which have different expansion coefficients. When there is a sudden change in temperature, for example, immediately after defrosting or being plugged in, the materials react to this with a characteristic crackling sound.
These sounds are often described as “shooting” or “popping”. They occur because different parts of the structure heat up or cool down at different rates. This is especially true for models with a No Frostsystem, where temperature changes are sharper. Typically, such sounds stop within a few hours or days after use.
⚠️ Attention: If the popping noise continues continuously for several days and is not related to compressor operating cycles, check whether shelves or food are touching the walls of the chamber. Foreign objects can enhance the resonance.
Often users notice that the equipment “shoots” precisely after loading a large amount of warm food. The sudden heating of the internal space causes the plastic to expand faster than usual. This is not a breakdown, but only indicates the active operation of thermal insulation and a change in the temperature regime inside the unit.
To minimize discomfort, it is recommended:
- 🧊 Do not place hot pots directly on the shelves without first cooling.
- 🌡️ Give the refrigerator time to stabilize after full defrosting before loading products.
- 🔧 Check whether the unit is level, since misalignment can increase the tension of the body materials.
Operation of the No Frost defrosting system
In models equipped with the system No Frost, popping noises may be associated with the operation of the evaporator and defrost systems. During the cooling process, condensation freezes on the evaporator, which is periodically removed by the heating element. When the ice is suddenly heated or, conversely, when it cools quickly after defrosting, sound effects resembling blows may occur.
In addition, some designs have a pressure relief or water overflow valve, which can also make clicking sounds. If you hear a popping sound when the compressor turns off or on, this may be due to a change in pressure in the defrost circuit. Such sounds are usually quiet and do not pose a threat to equipment.
There is an opinion that loud sounds during defrosting indicate a malfunction of the heating element. However, if the cold in the chambers remains and the on/off cycles are followed, most likely the system is working properly. The noise can be caused by drops of water falling on the hot element, or cracking of the plastic of the defrost tray.
Pay attention to the following signs of normal operation of the system:
- ❄️ Sounds occur cyclically, approximately once every 8-12 hours.
- 💧 No puddles of water under the refrigerator after sounds appear.
- 🔇 After the bang, the equipment continues to operate as usual without failures.
Problems with the compressor and start relay
The most serious cause of loud bangs is a malfunction in the electrical or mechanical part of the compressor. If you hear a loud click, after which the engine tries to start, hums for a few seconds and then clicks off again - this is a classic symptom of a malfunction of the motor windings. When it fails or the contacts stick, a sharp electrical discharge occurs, which sounds like a pop. At this moment, the engine cannot gain the required speed and goes into defense. Repeating such cycles may cause the compressor to burn out. start relay or motor windings.
The starting relay is responsible for supplying voltage to the starting winding of the compressor. When it fails or the contacts stick, a sharp electrical discharge occurs, which sounds like a pop. At this moment, the engine cannot gain the required speed and goes into defense. Repeating such cycles may cause the compressor to burn out.
⚠️ Attention: If you observe cyclic startup attempts with loud clicks, immediately unplug the device. Prolonged operation in this mode is guaranteed to lead to expensive repairs.
The compressor itself can also make a popping sound during water hammer if oil or liquid freon has entered the system, but this happens less frequently and usually after poor-quality repairs. In normal condition, a running motor emits a uniform hum, rather than sharp knocks. Diagnosing this problem requires professional tools.
How to check the starting relay yourself?
To check the relay, you need to remove the back cover, disconnect the wires and gently shake the relay. If a ringing sound is heard inside (as if from a loose nut), it means that the core is broken and the relay must be replaced. However, for accurate diagnostics it is better to use a multimeter.
The influence of voltage drops in the network
Unstable power supply is a frequent guest in old houses and rural areas. Sudden voltage surges can cause insulation breakdown or sparking in the contact groups of relays and thermostats, which is accompanied by a characteristic crackling or popping sound. The electronics of the refrigerator are very sensitive to the quality of the current.
If at the moment of the clap the light in the room flickered or the circuit breaker was knocked out, the reason lies precisely in the electrical network. In such conditions compressor it experiences colossal overloads. Modern inverter models are protected against surges, but older linear compressors can fail after several such incidents.
To protect your equipment, it is recommended:
- ⚡ Use a voltage stabilizer if surges in the network are regular.
- 🔌 Check the socket for burnt contacts or loose connections.
- 🛡️ Install a surge protector to smooth out minor interference.
Comparative table of noise causes
To make it easier for you to navigate the symptoms, we have prepared a summary table. It will help you quickly classify the sound you hear and understand the degree of danger of the situation. Remember that only a technician can make an accurate diagnosis after opening the unit.
| Sound type | Probable cause | Danger | Actions |
|---|---|---|---|
| Rare crackling sound plastic | Thermal expansion | No | Observation |
| Loud click + start | Start relay | High | Call a technician |
| Cotton during defrosting | No Frost system | Low | Check drainage |
| Crackling and sparks | Wiring problems | Critical | Disconnect from the network |
Diagnostics and elimination methods
If you decide to carry out the initial diagnosis yourself, start with a visual inspection. Make sure the refrigerator is stable and the adjustment feet are firmly pressed to the floor. Try rocking the body slightly: if it wobbles, this can increase any internal vibrations and create a popping effect when it comes into contact with furniture.
Next, listen to the periodicity of the sounds. If they are tied to the moment the motor turns on, the problem is most likely electrical. If the sounds are erratic and occur more often at night (when the house is quieter), it could be thermal expansion. It is also worth checking the rear grille: sometimes the vibration of the compressor causes the tubes to rattle if they touch each other.
☑️ Primary diagnosis of noise
In the case where you suspect thermal expansion, you can try to slightly change the temperature regime. Increase the difference between the temperature in the chamber and the room, but do not exceed the recommended values. Sometimes it helps to rearrange the products so that they do not fit tightly against the back wall, transmitting vibration.
When you need to call a specialist
There are a number of signs when independent experiments should be stopped. If after the bang the refrigerator stops freezing, but continues to hum or remain silent, this is a clear signal of a breakdown. The smell of burnt wiring or melted plastic should also alert you.
A technician will be needed if:
- 🔨 Popping noises are repeated every 5-10 minutes with an attempt to start.
- 🔥 You smell ozone or burning in the area compressor.
- 📉 The temperature in the chambers stopped decreasing after the sound signal.
Professional diagnostics include checking the resistance of the windings, the integrity of the starting relay and the pressure in the system. Replacing a relay or thermostat is a quick and inexpensive procedure if you do not delay the repair. Ignoring the problem can lead to the need to replace the compressor itself, which is up to 70% of the cost of a new refrigerator.
Frequently asked questions (FAQ)
Why does the refrigerator slam only at night?
At night, the house is usually quieter, and background noise is reduced, so the sounds of thermal expansion become audible plastic, which are masked by household noise during the day. Also, at night, the voltage in the network is often lower, which can make it difficult to start the compressor.
Is it dangerous if there was a bang once?
A single bang is most likely caused by a temperature difference or a power surge in the network. If the equipment continues to work normally and cool, there is no reason to panic. Just watch the device in the next 24 hours.
Can a new refrigerator clap?
Yes, new models, especially with the No Frost system, can make sounds when setting the temperature settings for the first time. The plastic is not yet “accustomed” to the heating and cooling cycles, so expansion occurs more noticeably.
What to do if the plugs are knocked out after the pop?
This is a sign of a short circuit. Do not turn on the refrigerator again until you find the cause. The device itself or the wiring in the wall may be faulty. You need to call an electrician.