The situation when the usual background hum of the refrigerator is replaced by an obsessive buzz, vibration or roar can lead to out of balance of anyone. Extraneous noise not only disrupts the comfort in the apartment, but also often serves as the first signal of an incipient breakdown, ignoring which can lead to the failure of expensive components. If the refrigerator begins to hum more than usual, it is important to quickly diagnose the source of the sound in order to prevent more serious consequences.
In this article we will analyze in detail the mechanical and electrical causes of increased noise in modern models Indesit, LG, Bosch and other brands. You will learn how to distinguish a normal operating sound from a sign of a malfunction, which structural elements are most often responsible for the hum, and whether you can fix the problem yourself without calling a technician.
Remember that diagnostics should start with simple things: checking the installation of the case and the presence of foreign objects. However, if a visual inspection does not produce results, you will have to delve into the technical details of the operation of the compressor-condensing unit.
Vibration of the housing and incorrect installation
The most commonplace, but common reason for amplification of sound is incorrect installation of the unit. If the refrigerator is not level, its body begins to resonate with the vibrations of the running engine, greatly increasing the hum. This is especially true for models with metal walls and a rear panel that work as speakers.
Users often forget that the floor under the refrigerator must be perfectly flat and hard. Linoleum, soft laminate or old parquet can be deformed under the weight of equipment, creating a misalignment. As a result, the refrigerator sways, and its legs or bottom rub against the coating, creating a characteristic low-frequency hum.
To fix the problem, you need to level the equipment horizontally. Use a spirit level and place it on the top lid of the refrigerator. Adjust the height of the front and rear support legs until the level bubbles are in the center position. It is also important to provide a gap between the back wall of the refrigerator and the wall of the room of at least 5-7 cm for free air circulation.
☑️ Checking the installation of the refrigerator
If the humming does not stop after leveling, check whether the internal shelves or drawers are touching the walls of the chamber during vibration. Sometimes it is enough just to move glass shelf or a plastic container to eliminate rattling.
Faults of the compressor and start relay
The heart of any refrigerator is the compressor, and it is this that most often becomes the source of noise when worn out or breakdown. If you hear a loud buzzing sound that turns into knocking or clanging, especially when starting or stopping the engine, the problem may lie in the valves. piston group. Over time, the metal of the engine parts wears out, backlashes appear, which create vibration. A faulty start relay may also be the cause. If the contacts in the relay are burnt or the mechanism is stuck, the compressor may hum, but not start, or work intermittently, making alarming sounds. or valves.
Over time, the metal of engine parts wears out, and backlashes appear, which create vibration. A faulty start relay may also be the cause. If the contacts in the relay are burnt or the mechanism is stuck, the compressor may hum but not start, or work intermittently, making alarming sounds.
How to distinguish the sound of a working compressor
A normally operating compressor emits a smooth, monotonous low-pitched hum. The sound should be barely audible at a distance of 1-1.5 meters. Any clicks, whistles, sudden changes in tone or metallic clanging indicate a malfunction of the internal mechanisms or electrical parts.
In some cases, inverter compressorbecomes the culprit. Although they are considered quieter, if the control board or windings fail, they can produce a high-frequency whistle or intermittent hum. Diagnostics of such systems requires special equipment.
⚠️ Attention: If the compressor hums very loudly and gets very hot (up to 80-90 degrees and above), immediately unplug the refrigerator. Continuing to operate in this mode may lead to a fire or complete jamming of the engine.
Problems with fans of the No Frost system
In refrigerators with the system No Frost fans are responsible for circulating cold air. There are usually two of them: one in the freezer, the other in the refrigerator compartment (in models with two circuits). If the refrigerator begins to hum, whistle, or make the sound of a running propeller, the reason often lies here.
Over time, the fan bearings dry out and wear out, which leads to noise during rotation. Another common problem is ice freezing on the blades or walls of the evaporator. An ice crust can interfere with the free rotation of the impeller, causing it to touch the housing or ice.
To check the fan, partial defrosting is often required. Leave the refrigerator turned off for 10-12 hours with the doors open. If, after complete defrosting and removing the ice, the noise disappeared, but returned after a few days, it means that the tightness of the circuit is broken or faulty Defrost heating element, and the water will again begin to freeze in the wrong place.
Wear of rubber bushings and shock absorbers
The compressor is not attached to the refrigerator frame rigidly, but through special rubber shock absorbers or bushings. Their task is to dampen vibrations that occur during engine operation. If these elements have dried out, cracked or jumped out of their places, the vibration is transmitted directly to the metal body, causing a strong hum.
You can check the condition of the shock absorbers by looking into the compressor niche (usually from the bottom rear). If you see that the motor is hanging on one side or metal parts are rubbing against the frame, the rubber bands need to be replaced. This is an inexpensive procedure that can often be performed independently.
It is also worth checking the spring suspensions on which the compressor unit itself is sometimes attached inside the casing. If the spring has burst or stretched, the motor will hang and rattle with each switching cycle.
Rattling of tubes and structural elements
At the rear of the refrigerator there is a condenser tube system and a capillary tube. They may vibrate when the compressor is running. If the tubes are located too close to each other or touch the body, a characteristic metallic rattling noise occurs, which users often confuse with the hum of the motor.
To eliminate this problem, you need to carefully bend them away from each other or from the body, trying not to damage the thin-walled tubes. Also check the condensation tray located above the compressor. If it is not installed tightly, it will resonate and rattle.
Pay attention to the rear metal grille. It is attached with clips or bolts. If the fastening is loose, the grille will rattle. Press it with your hand: if the sound disappears, just place a piece of rubber or thick cardboard at the fastening points.
Table: Diagnostics by sound type
To quickly determine the cause, compare the nature of the sound with a possible malfunction in the table below.
| Sound type | Probable cause | Difficulty of repair |
|---|---|---|
| Monotonous hum that turns into knocking | Wear of the compressor or start relay | High (requires a master) |
| Whistling, wind noise, crackling | Fan malfunction No Frost | Medium (fan replacement) |
| Metal rattling, ringing | Touching of tubes, loose body parts | Low (you can do it yourself) |
| Vibration, rumble | Improper installation, wear of shock absorbers | Low (adjusting the legs) |
When you need to call a specialist
Not all causes of humming can be eliminated with your own hands. If you have checked the installation, defrosted the unit, but refrigeration unit continues to work with abnormal noise, most likely the problem is inside the sealed circuit or in the electrics.
Cases are especially alarming when, along with noise, the refrigerator stops freezing or freezes too much. This indicates a freon leak or a malfunction of the thermostat. Also, you should not try to repair the compressor yourself without special tools and skills in working with refrigerants.
⚠️ Attention: Opening a sealed circuit or replacing a compressor requires a license and special equipment. Self-repair can lead to permanent breakdown and loss of warranty.
Is it possible to lubricate the fan?
Lubricating the fan bearing is a temporary measure. In domestic conditions, it is difficult to choose a suitable lubricant that will not freeze at low temperatures. Most often, it is more effective and cheaper to immediately replace the fan with a new one.
Prevention of noisy operation
In order for the refrigerator to serve for a long time and quietly, it is important to follow the operating rules. Regularly, at least once a year, defrost the unit (even the No Frost system) to completely remove ice. Wipe the rear grill from dust, as dust causes the compressor to overheat, which increases the load and noise.
Make sure that the food inside does not touch the rear walls of the chambers, especially in the area where cold air exits. This will prevent the formation of local ice and a decrease in the efficiency of the fans.
Timely maintenance and careful attention to the “sounds” of your equipment will help avoid costly repairs. If you hear changes in the operation of the refrigerator, do not delay diagnostics.
Frequently asked questions (FAQ)
Why does a new refrigerator hum more? old?
Modern refrigerators often use more powerful compressors and have better thermal insulation, which, however, can resonate. Also, in the first weeks of work, parts are being ground in. If the hum is not accompanied by knocking and vibration of the floor, this is normal.
Can an empty refrigerator hum?
Yes, an empty refrigerator can hum louder, since food acts as sound absorbers inside the chambers. In addition, the thermostat has to turn on the compressor more often to maintain the temperature in the empty volume.
Is it dangerous if the refrigerator hums and stops freezing?
Yes, it is dangerous for food. Most likely, there is a refrigerant leak or the compressor is seized. In this case, you need to turn off the equipment and call a technician.
How to reduce the noise of the refrigerator with your own hands?
Check the installation level, place anti-vibration pads under the legs, move the tubes away from each other, make sure that nothing is touching the body from behind.