A sudden noise from the refrigerator can disturb the peace in any apartment, especially at night. This sound is often the first signal that there have been changes in the operation of the unit that require attention. Intrusive noise does not always mean a critical breakdown, but you should not ignore it.
Modern models of household appliances are designed to operate as quietly as possible, but the physical processes occurring inside the system cannot be completely silent. Understanding the nature of the sounds will help you distinguish normal operation from an incipient malfunction. In this article we will analyze in detail the mechanics of noise occurrence.
First, it is worth assessing the nature of the sound: a monotonous hum, an intermittent crackling sound or a sharp whistle. Each of these acoustic signs indicates different components of the equipment. Diagnostics by ear is a primary, but extremely important stage in identifying the problem, allowing you to save time and money on calling a technician.
Natural sounds of refrigeration equipment
Some sounds are absolutely normal for compressor operation and refrigerant circulation. During the cooling process, freon constantly moves through the tubes, which may be accompanied by quiet gurgling or overflowing of liquid. This indicates that the circulation system is working properly.
Also, many owners notice a periodic hum, which either intensifies or subsides. This is due to the on and off cycles of the compressor. At the moment of starting, the motor picks up speed, creating a characteristic low-frequency hum, which gradually subsides when it reaches operating mode. Inverter models they can behave differently, smoothly changing the intensity of work, which is also the norm.
It is important to distinguish between background noise and an intrusive hum. If the sound does not interfere with normal life and does not increase over time, most likely the equipment is working properly. However, if the hum has become noticeably louder than when purchased, it is worth conducting a visual inspection.
⚠️ Attention: If the hum is accompanied by vibration of the body, which is transmitted to the floor or furniture, this is no longer the norm, even with a working compressor.
Problems with installation and vibration of the housing
One of the most common reasons for increased noise is improper installation of the unit. If the refrigerator is not level, the compressor is unbalanced, which leads to increased vibration and resonance. As a result, even the quiet operation of the motor turns into a loud hum, spreading throughout the apartment.
To eliminate this problem, you need to check the horizontalness of the installation. Use a building level or just rock the body. If it wobbles, the support legs need to be adjusted. Modern models are often equipped with anti-vibration pads under the legs, which also need to be checked for integrity.
In addition, the source of noise can be the proximity of the refrigerator to walls or furniture. The rear grille requires free space for air circulation. If the unit is moved close, the vibration is transmitted to the wall, which acts as a resonator, amplifying the sound many times over.
☑️ Installation diagnostics
Make sure that nothing vibrates inside the chamber. Sometimes bottles or cans standing on the door can rattle in time with the operation of the motor, creating the illusion of equipment failure. It is enough to simply rearrange them or compact the space.
Faults of the compressor and start relay
The compressor is the heart of the refrigerator, and it is it that most often becomes the source of strong humming. If the motor is running “pull”, trying to gain the required pressure, the sound becomes loud and intense. This may indicate wear of the internal mechanisms or problems with the electrical part engine.
A frequent cause of a loud humming noise when starting is a faulty start relay. This element is responsible for starting the engine. If the relay is stuck or fails, the compressor may hum but not start, or may make a loud clicking noise before turning on. In such a situation, the equipment operates with overload.
Prolonged operation of a faulty compressor leads to its overheating and eventual failure. If you hear that the engine is humming louder than usual and getting very hot, it is better not to take risks. Independent repair of this unit requires special knowledge and tools.
⚠️ Attention: An attempt to independently replace the compressor without evacuation of the system and filling with freon will lead to complete damage to the refrigeration circuit.
Symptoms of a dying compressor
The compressor may make sounds similar to metallic clanging or thuds inside the case. This indicates destruction of the motor mount inside the casing. In this case, replacing the unit is mandatory, since the vibration will only increase.
Fan and No Frost system
In refrigerators with a system No Frost fans are responsible for circulating cold air. Over time, dust accumulates in the fan bearings or the grease dries out, resulting in a characteristic howling or humming sound. This noise is usually constant as long as the fan is running.
Another problem is ice freezing on the blades or in the area of the rotating parts. Ice crust disrupts the balance of the impeller, causing beating and humming. Often this sound appears and disappears, depending on defrost cycles.
For diagnostics, you need to gain access to the fan. In a freezer this is usually the back wall. If the noise disappears or changes when you remove the panel, then the problem is with the fan. Replacing it is not a complicated procedure, but requires care.
Sometimes the fan can touch wiring or other elements if they have moved. Carefully inspect the space around the impeller for foreign objects.
The influence of chamber occupancy on the noise level
Few people know, but the noise level of the refrigerator directly depends on its load with products. An empty refrigerator runs louder, since the compressor has to turn on more often to maintain the temperature of the air, which quickly heats up when the door is opened.
The optimal load of the chambers is about 50-70%. Products accumulate cold and release it, smoothing out temperature changes and reducing the frequency of engine starts. However, overloading is also harmful: it disrupts air circulation, causing the fan and compressor to work harder.
If you just bought a refrigerator or defrosted it, let it idle for a couple of hours before loading it. This will allow the system to reach a mode without unnecessary load. Correct distribution of products also affects aerodynamics inside the chambers.
Comparison table of sources noise
For ease of diagnosis, we have collected the main symptoms and their probable causes in a table. This will help you quickly navigate the situation and understand whether specialist intervention is required.
| Sound type | Probable cause | Difficulty of elimination | Necessity of a specialist |
|---|---|---|---|
| Monotonous hum | Normal compressor operation | Not required | No |
| Case vibration | Incorrect installation | Low | No |
| Humming + clicking | Start relay malfunction | Medium | Recommended |
| Howling sound | Fan bearing wear | Medium | Optional |
| Loud humming + heating | Compressor wear | High | Yes |
Analyzing the table data, we can conclude that most problems can be solved without calling expensive services, if you pay attention to the nature of the sound in time.
When it is necessary to call a specialist
There are situations when independent experiments can lead to higher repair costs. If, after checking the installation and defrosting, the refrigerator continues to hum suspiciously loudly, you should think about professional diagnostics. Especially if the absence of cold is added to the noise.
An alarming signal is the smell of burning or melted wiring combined with humming. This indicates an electrical overload or a short circuit in the motor windings. In this case, the device must be immediately disconnected from the network.
Also, the help of a specialist is needed if the compressor needs to be replaced or the refrigerant circulation system needs to be repaired. These works require specialized equipment: a vacuum pump, a pressure gauge station and scales for refueling.
⚠️ Attention: Interfering with the sealed circuit of the refrigerator without a license and equipment is strictly prohibited and dangerous to life.
Prevention and care of equipment
If your refrigerator has been happy with silence for many years, it needs to be looked after. Regular defrosting (for drip systems) prevents the formation of ice plugs, which force the motor to work at its limit. The cleanliness of the condenser grille at the rear also affects the efficiency of heat transfer.
Once every six months it is recommended to check the tightness of the door seals. If the rubber becomes dry or dirty, warm air enters the chamber, causing the compressor to hum almost without interruption. Wipe the seal with a soft cloth and soapy water.
Do not place the refrigerator near heat sources: radiators, stoves, or in direct sunlight. Overheating of the external environment causes the cooling system to work more intensively, which inevitably leads to an increase in noise levels and energy consumption.
The secret of silence
By placing a special anti-vibration mat made of thick rubber under the legs of the refrigerator, you can reduce the transmission of vibration to the floor by 30-40%.
Why does the refrigerator hum after defrosting?
After defrosting, moisture may remain inside the system, which, when frozen, forms ice plugs in the capillary tube, causing noise. The compressor can also work more intensely, restoring the temperature in empty chambers. Give the equipment a few hours to stabilize the modes.
Is it normal that the refrigerator hums only at night?
During the day, extraneous noise can be masked by the background sound of the street or TV. At night, in silence, the standard hum of the compressor becomes audible. If the sound is monotonous and does not increase, this is normal.
Can an old refrigerator hum louder than a new one?
Yes, over time, the engine bearings wear out, and the rubber shock absorbers of the compressor suspension dry out. Natural wear and tear leads to an increase in noise level by 10-15% of the original value.
How to check if the compressor or fan is humming?
Open the refrigerator door. On most models, the fan stops when the door is open. If the hum disappears, the problem is in the fan. If the hum remains, the source of the noise is the compressor.