Modern household appliances are becoming quieter, but they cannot be completely silent. Work cycle any unit is accompanied by a characteristic hum, which indicates the normal functioning of the system. Many owners begin to panic at the slightest change in the acoustic background, although often there is no reason to worry.
Understanding the nature of the occurrence of sounds helps to distinguish normal operation from harbingers of a breakdown. Refrigerantcirculating through the tubes and the running motor create a specific sound background. It is important to learn to recognize these signals so as not to miss the moment when the equipment really needs the intervention of a specialist.
In this article we will analyze in detail which sounds are normal and which require immediate attention. You will learn about permissible noise levels and methods for diagnosing problems by ear.
The physics of the compressor and the permissible noise level
The main source of sound in the refrigerator is the compressor. This is the heart of the system, which compresses the refrigerant and forces it to circulate in a closed circuit. Inverter models They work much quieter than the old linear analogues, since they do not turn on at full power constantly, but smoothly regulate the speed.
In normal mode, the device emits a monotonous, low-frequency hum. Its level usually does not exceed 36-40 dB, which is comparable to a quiet whisper. If you are in another room, a running unit should attract little or no attention. However, at night, when extraneous noises subside, even standard humming may seem intrusive.
The intensity of the sound depends on several factors, including the location of the equipment and its technical condition. For example, old models with rotary compressors can be noticeably louder than modern analogues.
- 🔊 A monotonous hum is a sign of the motor operating in normal mode.
- 🌬️ A quiet whistle is the movement of freon through capillary tube.
- 🔄 Rhythmic humming - fan operation in the No Frost system.
It is important to consider that when starting or stopping the engine, the noise level may increase briefly. This is due to starting currents and inertial processes in the mechanism.
Normal sounds: gurgling, clicking and shimmering
There is a whole range of sounds that can alert an inexperienced user, but are absolutely normal for a working device. Most often, people are frightened by the gurgling or overflow of liquid inside the case.
These sounds arise due to circulation refrigerant. In a liquid state, freon flows from the condenser to the evaporator, and in a gaseous state it returns back. This process is accompanied by a characteristic “murmuring”, especially noticeable immediately after the compressor is turned off or at the time of its startup.
⚠️ Attention: If the gurgling is accompanied by a complete absence of cold in the chambers, this may indicate a freon leak. In normal mode there is sound, but the cold remains.
Another common type of sound is clicking. They can be rare and voiceless or frequent and voiced. Dull clicks are usually produced by thermostat or a protection relay, turning the compressor on and off when the set temperature is reached.
Audible clicks are often heard in models with the system No Frost. This is what a plastic case sounds like during thermal expansion. When the temperature inside the chamber changes, the parts change their volume slightly, producing a crackling sound similar to the cooling of the plastic of a car.
Alarm signals: when the humming becomes a problem
Not all sounds are safe. There are acoustic signs that indicate wear of parts or violation of operating conditions. If the refrigerator begins to make sounds that were not there before, or the usual noise has become much louder, this cannot be ignored.
One of the common problems is increased vibration. If the housing shakes and hums loudly, the installation geometry is most likely broken. The legs should fit snugly to the floor, and the unit itself should not touch the walls or furniture.
It is also worth paying attention to the nature of the hum of the motor. If instead of a smooth low-frequency hum you hear a metallic clanging, knocking or high-pitched whistle, this indicates a mechanical malfunction.
| Sound type | Probable cause | Danger level |
|---|---|---|
| Metal clanging | Wear of the compressor piston group | High (needs replacement) |
| High-pitched whistle | Freon leak or problem with the fan | Medium (needs diagnostics) |
| Loud vibration | Incorrect installation or contact of tubes with the housing | Low (can be corrected) |
| Crackling of plastic | Thermal expansion (No Frost) | Safe (normal) |
Special attention is required when noise is accompanied by heating of the case or lack of cooling. In this case diagnostics should be carried out as soon as possible.
☑️ Diagnosis of the noise source
The influence of the defrosting system on acoustics
Refrigerators with manual defrosting and systems No Frost (or Low Frost) sound different. In conventional models, the main sound is the operation of the compressor and the movement of liquid.
In systems with automatic defrosting, fan operation is added. It circulates cold air throughout the chamber. If the fan is working properly, it creates a smooth air flow. However, over time, moisture or dust can get into the bearings, which leads to a hum or whistle.
Another specific sound is hissing or crackling during defrosting. In some models, the heating element, when turned on, may make a hissing sound, interacting with residual moisture on the evaporator.
If a loud knocking or grinding noise is heard in the refrigerator No Frost this often indicates that the fan blades are touching frozen ice. This occurs when the defrost system is malfunctioning.
Why does the fan make more noise in winter?
In winter, the humidity in the room may be lower, but if the door is opened frequently, warm, humid air gets inside. When in contact with cold elements, it quickly turns into ice, which can block the fan.
External factors: installation and environment
Often the cause of excessive noise is not a breakdown, but an incorrect installation. A refrigerator is a massive unit that is sensitive to the evenness of the surface.
If one of the legs does not reach the floor, the body warps and the compressor begins to operate with increased vibration. It is also important to check the distance to the walls. The gap should be at least 5-10 cm for free air circulation.
Check that the condenser pipes or other elements are not touching the rear wall of the case or each other. When the motor is running, the pipes vibrate and any contact causes rattling.
- 📏 Check that the installation is horizontal with a level.
- 🧱 Make sure that the back wall does not touch the kitchen wall.
- 🔌 Inspect the wires from the back - they should not touch the compressor.
Sometimes objects standing on the lid of the refrigerator become the source of resonance. Vases, jars or decorative elements can vibrate intensely and create unpleasant noise.
⚠️ Attention: When moving the refrigerator, make sure that the shipping bolts (if they were on the compressor) are removed and the protective film is removed from the heat exchanger, as it can rustle.
Diagnostics of malfunctions by the nature of the sound
An experienced technician can determine the malfunction simply by listening to the operating unit. Different breakdowns have unique acoustic signatures. For example, if the compressor hums, but does not start, and after a few seconds there is a click and the hum stops, this is a sign of a faulty start relay or motor windings.
If you hear a constant, incessant sound of pouring water, even when the compressor is not running, this may indicate a clogged capillary tube or an excess of oil in the system.
A whistling sound often indicates that the refrigerant is escaping under pressure through a microcrack. In this case the tightness of the circuit is broken, professional repairs with leak detection and refilling are required.
It is important to distinguish between the sounds made by the refrigerator itself and the sounds that it resonates. Tap the body with your hand. If the sound changes or disappears, then the problem is in the resonance of the panels or fasteners.
Why does the refrigerator make a “gurgling” sound after turning off?
This is an absolutely normal physical process. After the compressor stops, the pressure in the system equalizes. Liquid refrigerant continues to flow through the tubes under the influence of gravity and pressure differences, creating the characteristic sounds of overflowing liquid. This may last several minutes.
Is it dangerous if the refrigerator starts to crackle like an old TV?
If the crackling sounds like an electrical discharge and is accompanied by a burning smell or sparking (visible through the vents), it is dangerous. You must immediately unplug the device from the outlet. If the cracking sounds like plastic cooling, it is safe.
Can an old refrigerator be quieter than a new one?
As a rule, no. Older models with linear compressors and mechanical controls are always noisier than modern inverter ones. If the old unit begins to operate quieter, the piston group may have worn out and it has stopped developing the required power, which leads to spoilage of food.
What to do if noise appears after defrosting?
After defrosting, water may remain in the system, which makes sounds when frozen or moved. The condensate tray may also have moved. Let the refrigerator run for a day. If the noise does not subside and is disturbing, check to see if the drainage is frozen.