Silence in the house is certainly good, but absolute silence in the kitchen, where refrigeration equipment operates, often raises more questions than peace of mind. Many owners of new equipment get scared when they hear the first buzz, click or incomprehensible gurgling, and begin to frantically search for information about what sounds does a refrigerator make? in normal operation. In fact, modern climate control technology is a complex mechanism in which physical and chemical processes are constantly occurring, accompanied by acoustic effects.
Understanding the nature of noise helps not only to preserve nerve cells, but also to diagnose a serious malfunction in time, preventing expensive repairs. Compressor, refrigerant and the defrost system - the main sources of acoustics in your unit. In this article, we will analyze in detail the spectrum of noise, divide them into normal and emergency, and also give recommendations for reducing the level of discomfort if the hum becomes intrusive.
Physics of silence: why the refrigerator cannot be silent
The operation of any refrigeration unit is based on the cyclic compression and expansion of the refrigerant, which transfers heat from the chamber to the outside. This process physically cannot be silent, since it is associated with the movement of mechanical parts and changes in the state of matter. Normal noise is an inevitable consequence of the work of the compressor, which is the heart of the system. Even in the most expensive models with inverter control, it is impossible to completely eliminate sound; you can only reduce it to a minimally audible level.
In addition, there is circulation inside the system freon, which, when transitioning from a liquid to a gaseous state and back, produces characteristic sounds. If you heard absolute silence from a running unit, this could be a cause for concern as it would mean the cooling cycle has stopped. It is important to learn to distinguish between a monotonous, even hum, which indicates normal operation, and sharp, intermittent or increasing noises.
It is also worth considering the case material and the quality of installation. Plastic and thin metal can resonate, increasing the vibration from the motor The permissible noise level for household refrigerators usually does not exceed 40 dB, which is comparable to a quiet conversation or whisper. If your device sounds louder than a vacuum cleaner or hammer drill, this is a clear signal to action.
⚠️ Attention: If the new refrigerator makes a loud metallic clang or whistle immediately after turning it on, do not wait until the warranty expires term. This may indicate a manufacturing defect in the compressor or a transportation failure in which oil got into the circuit.
Normal sounds of a working refrigerator
To distinguish a breakdown from the norm, you need to know the “voice” of a healthy unit. There are a number of sounds that are standard and do not require the intervention of a specialist or user. First on the list is the hum of the compressor. It can be uniform or change tone depending on the load on the system. Modern inverter models are quieter and change speed smoothly, while old linear compressors can hum quite loudly, especially at the time of startup.
The second common sound is gurgling and overflowing. They occur in the system tubes through which the refrigerant moves. These sounds are heard especially clearly immediately after the engine is turned off or at the moment it stops, when the pressure in the system is equalized. You can also often hear quiet crackling or clicking noises produced by the plastic of the internal housing when the temperature changes (thermal expansion of materials).
- 🔊 Uniform low-frequency hum is a sign of the operation of the motor-compressor, the intensity of which depends on the selected cooling mode.
- 💧 Murbling and gurgling —the sound of freon moving through the capillary tube and evaporator, is absolutely normal for any No Frost and drip-type systems.
- 🔌 Single click —activation of a thermal relay or starting device when the engine is turned on or off.
- ❄️ Quiet crackling - the reaction of plastic panels and chamber walls to temperature changes (expansion and compression).
Particular attention should be paid to the sounds in refrigerators with the system No Frost. They periodically turn on a fan that drives cold air through the chambers. Its operation is accompanied by characteristic wind noise or air flow. Also, in such models, the defrosting heating element may turn on once every few hours, which is sometimes accompanied by a hissing or quiet crackling sound of melting ice on the evaporator.
Alarm signals: what sounds indicate a malfunction
Not all sounds are safe. There are acoustic markers that indicate that the system has failed. If you hear what sounds like metal hitting metal, this may mean that the compressor is falling apart internally or that its mounting bolts have become loose. In such cases, the motor may vibrate strongly, and the unit itself may “jump” on the floor. loud knockingsound similar to metal hitting metal, this may mean that the compressor is “falling apart” from the inside or its mounting bolts have become loose. In such cases, the motor may vibrate strongly, and the unit itself may “jump” on the floor.
Another dangerous sound is a high-pitched whistle or hissing. Most often it indicates a refrigerant leak. If freon comes out under pressure through a microcrack, this is exactly the sound effect that occurs. Ignoring this symptom will lead to a complete loss of cooling capacity and combustion of the compressor, which will work non-stop, trying to gain temperature.
You should also be wary if the hum becomes intermittent, jerky, or is accompanied by a hum that turns into a hum with increasing strength, which ends abruptly. This often indicates problems with the starting relay or a break in the motor windings. Vibration, transmitted to the floor and adjacent furniture, may indicate that the refrigerator is not level or the shock absorbers are worn out.
☑️ Diagnostics by sound
Specific sounds in different types of refrigerators
Different designs of refrigeration units make different noises. Understanding these differences will help you better determine whether your equipment is behaving normally. The main difference lies in the type of compressor and defrosting system.
Linear compressors, which are often found in LG appliances and some models of other brands, operate with a characteristic click when starting and stopping. They can produce a louder startup sound compared to their inverter counterparts. Inverter compressors (for example, in Samsung or Bosch) they operate almost continuously, but at low speeds, so their sound is smooth, barely audible hiss or hum, without sudden starts.
B systems No Frost fan noise is added. If you hear the fan humming louder than usual or making a grinding noise, it may be frozen or the bearings are worn out. In drip systems (“crying butt”) there is no fan, so they are quieter, but the gurgling of freon is more clearly audible in them.
| Type of system | Characteristic sound | Normal or pathology | Cause |
|---|---|---|---|
| Linear compressor | Loud click, hum | Normal | Sharp start/stop of the motor |
| Inverter compressor | Quiet hissing, howling | Normal | Smooth speed control |
| No Frost | Wind noise, crackling | Normal | Fan operation and defrosting |
| Any type | Whistling, hissing | Pathology | Freon leakage |
| Any type | Metal knocking | Pathology | Compressor destruction |
External factors that increase noise
Sometimes the refrigerator itself is working properly, but its operating conditions make it noisy. Often the problem lies not in the insides of the unit, but in the way it is installed. Vibration is the main enemy of silence. If the legs of the refrigerator are not adjusted and it is not level, the body begins to resonate, increasing the hum of the motor significantly.
Objects standing on or next to the refrigerator can also become a source of noise. Vases, jars, bottles placed on the lid begin to rattle from vibration. The back wall of the refrigerator should not touch the wall or furniture - a gap is necessary for air circulation and to prevent vibration transmission. Check whether the internal shelves or dishes are touching each other.
- 📏 No gap - if the refrigerator is moved close to the wall, it may hum more due to poor ventilation and resonance.
- 🥘 Foreign objects - any small thing on the lid or in the immediate vicinity may vibrate.
- 🧊 Overcrowding —if products touch the back wall or each other, they can make sounds when air circulates.
- 🧱 Uneven floor —lack of stability causes the housing to wobble and rattle when the motor is running.
⚠️ Attention: Do not install the refrigerator next to a sink or window if there are water supply pipes there. Vibration from a running compressor can be transmitted through the pipes and create an echo throughout the entire apartment.
Do-it-yourself methods for reducing noise levels
If you are convinced that there are no technical faults, but the sound is still annoying, you can try to reduce its level yourself. The first thing to do is set the level. Use a building level or simply rock the unit. It must stand firmly on all four legs. Tighten the adjustable supports so that the front legs are slightly higher than the back ones - this will ensure a tight fit of the door and stability.
Check the distance to the walls. It should be at least 5-10 cm. If the refrigerator is built into a niche, make sure that it does not touch the cabinet walls. You can lay a piece of vibration-isolating material or dense rubber between the body and the furniture. Also inspect the condenser grille from behind: if it is deformed and touches the body or tubes, it must be carefully (with the device turned off!) bent back.
Procedure for noise reduction:1. Turn off the refrigerator from the network.
2. Move away from the wall.
3. Check and remove foreign objects from the roof and around.
4. Level the adjustable legs.
5. Check that the shelves and jars inside do not touch each other.
6. Turn it on and evaluate the result.
If the noise comes from the vibration of the tubes from behind (often they rattle against each other), you can carefully, with caution, move them apart or place a piece of porous material between them. However, it is better not to experiment with internal components without skills.
When it is necessary to call a specialist
There is a clear boundary when independent experiments should be stopped and a specialist should be called. If you hear loud knocking inside the compressor, which is accompanied by the fact that the refrigerator has stopped freezing, this is a sign of destruction of the valve group or piston system. Repair in this case is often unprofitable; the compressor needs to be replaced. inside the compressor, which is accompanied by the fact that the refrigerator has stopped freezing, is a sign of destruction of the valve group or piston system. Repair in this case is often unprofitable; the compressor needs to be replaced.
If you hear a whistle and smell oil or chemicals, or notice that the motor is running non-stop (does not turn off for hours) trying to cool the chamber, immediately turn off the device. These are symptoms of a freon leak or a jammed compressor. Further work will lead to burnout of the windings.
Help is also needed if the noise is accompanied by errors on the display (if any) or if after a loud click the refrigerator no longer turns on. In these cases diagnostics professional equipment is necessary to accurately determine the cause.
Why did the refrigerator begin to make more noise after defrosting?
If after defrosting the noise increased, perhaps you did not dry the unit well enough, and water got into the drainage system or onto the working nodes. The fan could also have moved. Leave the refrigerator turned off for a few more hours. If the noise does not go away, diagnostics are needed.
Is it normal that the refrigerator hums only at night?
During the day, the noise can be masked by household sounds. At night, in silence, the hum becomes more noticeable. In addition, at night the network voltage may be more stable and the compressor operates at full capacity. If the hum is smooth, this is normal.
Can an old refrigerator operate silently?
No, over time the rubbing parts wear out, the lubricant thickens or dries out, which leads to an increase in the noise level. Old linear-type models will always make more noise than modern inverter analogues.
Is the cracking of plastic inside the chamber dangerous?
The cracking of plastic itself is safe. However, if the cracking sound is very loud and frequent, this may indicate sudden temperature changes, which is undesirable for the food. Check the tightness of the door closure.
What to do if the refrigerator is humming but not freezing?
This is a critical situation. Most likely, there is a freon leak or a compressor failure. Immediately disconnect the appliance from the network so as not to burn the motor, and call a technician.