The constant hum from the refrigerator can turn life in an apartment into a test of the strength of the nervous system. This low-frequency, monotonous sound penetrates the walls and interferes with rest, especially at night. Vibrationtransmitted to the furniture body only increases general irritation and creates a feeling that expensive equipment is malfunctioning.
Before calling a technician or planning to purchase a new unit, it is worth conducting a detailed diagnosis. In most cases, loud noise is not caused by a breakdown of internal mechanisms, but by improper installation or natural wear of small parts. Understanding the physics of the process will help you quickly localize the source of sound and eliminate it without extra costs. noise caused not by a breakdown of internal mechanisms, but by improper installation or natural wear and tear of small parts. Understanding the physics of the process will help you quickly localize the source of the sound and eliminate it at no extra cost.
Modern models, be it Indesit, LG or Atlant, work quieter than their old Soviet counterparts, but they are not immune to problems. In this article, we will look at why the refrigerator began to hum, whistle or crackle, and what steps need to be taken to restore silence.
Natural causes of noise and design features
A hum does not always indicate a breakdown. Modern refrigeration units are equipped with powerful compressors, which at certain moments of operation can produce characteristic sounds. For example, when you turn it on for the first time or after defrosting, the motor runs at maximum speed to quickly reach the set temperature. During this period noise level may be significantly higher than usual.
One of the common reasons is the operation of the system No Frost. Air circulation through the channels and periodic turning on of the fans create a constant background hum. It is also worth considering that the refrigerant, flowing through the tubes, can make gurgling sounds, especially if the refrigerator has recently been transported or tilted.
⚠️ Attention: If the hum is accompanied by a strong burning smell or smoke, immediately disconnect the appliance from the power supply. This may indicate a short circuit or overheating of the wiring, which creates a risk of fire.
It is important to distinguish between an operating hum and a malfunction sound. Operating noise is usually smooth and predictable. If the nature of the sound changes to intermittent, knocks or grinding sounds appear, this is a signal that intervention is necessary. It is also worth noting that two-compressor models Bosch or Siemens may hum louder, since they operate two motors independently of each other.
Why does a new refrigerator make more noise than an old one?
New models often use inverter compressors that do not turn off completely, but only slow down. This creates a constant low-frequency hum that can be irritating to the ear, although the device is technically sound and energy efficient. Old models simply fell silent more often, creating the illusion of silence.
Installation problems: vibration and touching objects
The most commonplace, but common reason why a refrigerator hums is incorrect installation. If the body of the unit touches a wall, kitchen furniture or other objects, vibration from the running motor is transmitted to them. As a result, objects begin to resonate and amplify the sound, creating an unpleasant hum throughout the kitchen.
It is necessary to provide a gap between the back wall of the refrigerator and the wall of at least 5-10 centimeters. This distance is necessary not only to reduce noise, but also for normal circulation of air cooling the condenser. Check whether the side walls of the cabinets or adjacent equipment are touching.
☑️ Checking the installation of the refrigerator
Another critical point is the horizontal installation. If the floor is uneven or the legs are not twisted correctly, the body will warp. This can cause the door to not fit properly and the compressor to work harder, producing a louder noise. Use a building level to check the position of the unit.
- 🔹 Move the refrigerator away from the wall and turn it on to check if the resonance has disappeared.
- 🔹 Check whether the device is stable: press on the corners, it should not wobble.
- 🔹 Make sure there are bottles and containers inside the chamber do not touch the walls or each other.
- 🔹 Inspect the space behind for forgotten objects that have fallen behind the equipment.
Faults of the compressor and start relay
If the installation is done correctly, and the hum does not stop, perhaps the problem lies in the heart of the refrigerator - compressor. This is an electromechanical pump that compresses the refrigerant. Over time, the motor shaft bearings wear out, play appears, which leads to increased vibration and loud humming.
A frequent cause of noise is a faulty start relay. This element is responsible for starting the engine. If the relay contacts are burnt or the mechanism is jammed, the compressor may hum but not start, or operate with a characteristic crackling and humming noise. In such cases, the relay often requires replacement, which is a relatively inexpensive repair.
⚠️ Attention: Compressor diagnostics require working with live electrical current. If you do not have electrical installation skills, it is better to entrust this task to a professional technician.
In some cases, the hum may be caused by the compressor casing itself. The metal casing is bolted on, and if the fasteners become loose, it begins to vibrate in time with the engine. Sometimes it is enough to simply tighten the nuts or lay vibration-insulating material between the casing and the frame to fix the problem.
No Frost system fan: diagnostics and lubrication
In refrigerators with the system No Frost the fan is responsible for circulating cold air. Over time, dust can stick to its blades, and moisture can get into the bearings, which turns into ice when it freezes. This leads to imbalance of the impeller and the appearance of a strong hum or crackling sound.
Often the sound intensifies when you open the door. On many models, the fan should stop when the door is opened. If the hum stops when the door is open, then the problem is with the evaporator fan. Ice can block rotation, causing the motor to overload.
To fix the problem, defrosting the refrigerator is often required. Unplug the appliance for 10-12 hours (without opening the door to allow the ice to melt inside). If after switching on the hum disappears, then the cause was ice. If the sound returns after a few days, the fan will need to be disassembled and lubricated or replaced.
- 🔹 The fan blades can become deformed over time and touch the channel walls.
- 🔹 Lack of lubrication in the fan bearings causes a high-pitched whistle or hum.
- 🔹 Hit foreign objects in the impeller rotation zone causes a crackling sound.
- 🔹 The fan electric motor may fail and hum when trying to rotate.
Vibration of pipelines and fasteners
The refrigerant circulation system consists of many copper tubes. During operation, the compressor creates pulsation, which is transmitted to the pipelines. If the tubes are too close together or touch the housing, they begin to rattle and hum, creating a high-frequency noise.
Loosening the mounting bolts of the compressor itself is also a common problem. The rubber shock absorbers on which the motor is mounted dry out or lose elasticity over time. As a result, the metal housing of the motor begins to hit the frame, producing loud knocks and hums.
To eliminate the noise of the tubes, they must be carefully bent, increasing the gap. However, this must be done with extreme caution, since copper breaks easily, and damage to the circuit will lead to freon leakage and costly repairs. It is better to use vibration-isolating pads made of rubber or foam rubber.
| Sound type | Probable cause | Elimination method | Complexity |
|---|---|---|---|
| Low hum | Incorrect installation, touching walls | Alignment, moving away | Low |
| Rattling | Touching the tubes, loose bolts | Bending the tubes, tightening | Average |
| Whistling/Howling | Fan No Frost | Defrost, lubrication, replacement | Average |
| Knock/Clanging | Compressor, relay | Replacement of parts | High |
When you need to call a technician: critical breakdowns
Exist situations where independent repairs not only will not help, but can also aggravate the situation. If the hum is accompanied by a complete lack of cold, this may indicate a refrigerant leak or a clogged capillary system. In such cases, the compressor may work continuously, trying to compensate for the loss of pressure, and make a loud noise.
Hydraulic hammer in the compressor is another serious cause of noise. This occurs when liquid freon enters the compressor cylinder instead of gaseous freon. This operating mode is destructive to the valve group and piston system. It is characterized by loud, sharp sounds, similar to blows.
⚠️ Attention: Opening a sealed circuit or trying to fill the refrigerator with freon yourself is strictly prohibited without special equipment and a license. This is dangerous to health and life.
It is also worth contacting specialists if the hum appears after a power surge in the network. The motor windings or control electronics could have failed. Modern inverter models Samsung or LG have a complex diagnostic system, and attempting to repair it yourself can lead to loss of warranty.
Why does the refrigerator hum only at night?
At night, the overall level of background noise in the apartment decreases, and the operation of the refrigerator becomes more noticeable. In addition, the power supply voltage often drops at night, which can cause transformers to hum or change the operation of the compressor. Also at night, the ventilation in the house is quieter, which increases the echo.
Can an empty refrigerator hum?
Yes, an empty refrigerator can hum louder than a full one. Food and water have a high heat capacity and act as acoustic absorbers, reducing resonance inside the chambers. In addition, a full refrigerator is less likely to turn on, since it keeps the cold longer.
Is it normal if the refrigerator hums after defrosting?
Immediately after defrosting and turning on, the compressor works in increased mode to cool the warm volume of the chamber. At this time, the hum may be stronger than usual. This is normal if after a few hours, when the temperature stabilizes, the sound becomes quieter.
How to lubricate a fan without disassembling the refrigerator?
Unfortunately, it is impossible to properly lubricate the fan bearing without disassembling it. Trying to drip oil through the holes will not have a long-term effect and may damage the plastic. Access to the motor axis is required for cleaning and applying a special frost-resistant lubricant.