The situation when a refrigerator suddenly starts making unusual sounds is familiar to many owners of household appliances. A hum, knocking, gurgling or whistling can not only be annoying, interfering with rest and sleep, but also indicate serious malfunctions of internal systems. Extraordinary noise is the first symptom that cannot be ignored, as it often precedes a breakdown of the compressor or defrost system. In this article, we will look in detail at why the unit makes strange sounds, how to carry out initial diagnostics, and what steps need to be taken to restore silence.
Before you panic or call a repairman, it is important to understand the nature of the sounds. Sometimes the hum is caused by trivial reasons, such as improper installation or vibration of the dishes inside the chamber. However, if you hear metal clanging or a loud cracking sound, this may indicate an engine or coolant problem. Understanding the difference between an operating hum and an alarm will help you save time and money, as well as extend the life of your appliances.
Natural sounds of refrigeration equipment
Not all sounds coming from the kitchen are a sign of a breakdown. Modern models, especially those equipped with the No Frostsystem, produce characteristic noises during cyclic operation. A quiet hum from the compressor is considered normal, which may intensify when the engine is turned on or off. A slight gurgling or overflow of liquid is also acceptable, which indicates the movement of refrigerant through the tubes of the evaporator and condenser.
In models with automatic defrosting, plastic cracking or clicking may be periodically heard. This occurs due to thermal expansion and contraction of the materials of the inner chamber and evaporator. Thermoregulator also makes clicking sounds when switching operating modes. If these sounds are quiet and not constantly intrusive, then most likely everything is fine with your refrigerator.
⚠️ Attention: If you have just installed a new refrigerator, let it stand turned off for several hours before starting it for the first time. This is necessary to stabilize the oil in the compressor, which will help to avoid unnecessary noise at start-up.
It is important to distinguish between a monotonous operating hum and intermittent, sharp sounds. Inverter compressors, for example, they operate much quieter than traditional ones, creating a barely noticeable background noise. If your old unit suddenly begins to sound differently, you should listen more carefully.
Diagnostics of external causes of noise and vibration
Before disassembling the case or checking the electronics, it is necessary to exclude external factors. Often the cause of excessive noise lies in improper installation of the unit. If the refrigerator is not level, vibrations from the compressor are transmitted to the housing and amplified, creating a resonance effect. This is the most common reason why the refrigerator vibrates and hums more than usual.
The second important aspect is the contact of the case with furniture or walls. Even the slightest touch of the rear radiator grille against the wall or the side panel against the kitchen unit can cause rattling. Make sure that there is a gap of at least 5-7 centimeters between the back wall of the unit and the kitchen wall for free air circulation and the absence of vibration contacts.
- 🛠️ Check the adjustment of the legs: use a building level to make sure that the refrigerator is level. Tighten the front supports so that the housing is slightly tilted back.
- 🧊 Inspect the interior: make sure that bottles, cans and containers do not touch each other or the walls of the chamber, as they can rattle when vibrating.
- 🔌 Check the back panel: make sure that wires, tubes or other objects do not touch the operating compressor or radiator.
If after eliminating these factors the noise does not disappear, the problem may lie deeper. Sometimes vibration is caused not by the unit itself, but by the floor. On wood or laminate floors, the coating may resonate with the frequency of the engine. In this case, you can place special anti-vibration pads or a piece of thick rubber under the legs of the refrigerator.
☑️ Diagnostics of external noise
Problems with the compressor and start relay
The heart of any refrigerator is the compressor. It is he who is responsible for circulating the refrigerant and creating cold. If you hear a loud, intrusive hum that gets worse over time, or a metallic knocking sound, the problem may be worn out engine parts. Shaft bearings engines wear out over time, which leads to beating and characteristic noise. In older models, this is often accompanied by overheating of the motor housing.
Another common reason is a malfunction of the starting relay. This small element is responsible for starting the engine. If the relay is faulty, the compressor may attempt to start, make a loud clicking or humming noise, and then shut down. This condition is dangerous because it can lead to burnout of the motor windings. Starting device subject to replacement, and you can do this yourself if you have basic skills.
⚠️ Attention: If the compressor hums, but does not start, and after a while there is a click and it starts again goes silent - immediately unplug the device. Operation in this mode will lead to burnout of the motor windings.
For diagnostics, you need to remove the back cover at the bottom of the refrigerator. Visually inspect the compressor for damage, oxidation of contacts or signs of overheating. If, when you touch it with your hand (be careful, it may be hot!) you feel a strong vibration of the motor housing, different from normal operation, this is a sure sign of a mechanical malfunction.
How to check the starting relay?
Remove the relay from the compressor contacts (after first disconnecting the refrigerator from the network). Shake it near your ear. If you hear a ringing or knocking sound inside, it means the core is broken and the relay needs to be replaced. Also check the contacts for the presence of carbon deposits.
Noise in the No Frost system and fan
In refrigerators with the system No Frost fans are responsible for circulating cold air. Over time, malfunctions may occur in their operation, leading to noise. Most often, the problem is associated with freezing of the blades or wear of the fan hub bearings. If you hear a cracking sound similar to the sound of falling leaves, or a periodic hum that increases and decreases, it is worth checking this particular unit.
Ice can build up on the evaporator and touch the fan blades if the defrost system is not working correctly or the door has been open for a long time. In this case, the fan blades begin to beat against the ice crust. Defrosting the refrigerator within 10-12 hours often solves the problem by allowing the ice to melt. However, if the noise returns immediately after switching on, the reason may be deformation of the fan housing or failure of its motor.
| Type of sound | Probable cause | Solution method |
|---|---|---|
| Crackling noise of leaves | Ice on the fan blades | Complete defrosting (24 hours) |
| Monotonous hum/howl | Fan bearing wear | Lubricating or replacing the fan |
| Case vibration | Wires touching the fan | Securing wires with clamps |
| Intermittent knocking | Deformation of the impeller | Replacing the fan assembly |
It is also worth checking whether foreign objects have entered the rotation zone of the blades. Sometimes pieces of the packaging or label may come off and end up inside the duct. To access the fan in most models No Frost you need to remove the back panel inside the freezer.
Foreign objects and rattling of parts
Sometimes the source of annoying rattling is not mechanisms, but small structural parts or forgotten things. During operation, the screws securing the compressor, condenser grille or plastic panels may become loose. The vibration of a working unit causes them to rattle, creating the effect of a malfunction. Fastening elements require periodic checking and tightening.
Particular attention should be paid to the condensate collection tray, which is located above the compressor. If it is loose or misaligned, it will vibrate as the motor operates. Also, the source of sound can be the drip tube itself if it touches the metal parts of the housing. It is enough to slightly bend the tube or place a piece of foam rubber under the tray to eliminate the noise.
- 🔩 Tighten all visible screws on the back wall and at the bottom of the refrigerator.
- 🧊 Check the evaporator tray: it should fit tightly, without play.
- 🔌 Inspect the copper tubes: they should not touch each other or the walls of the case.
Don't forget to look inside the chambers. Shelves, especially glass ones, can rattle in the plastic guides. Silicone pads or simply repositioning the shelf often solves the problem. Also check the door shelves: if they are poorly secured, they will rattle when the door slams or from vibration of the floor.
When you need to call a technician: critical symptoms
There are a number of situations when self-repair not only will not help, but can also be dangerous. If, after carrying out all the above checks and eliminating external causes the refrigerator continues to make noise, the problem probably lies inside the sealed circuit or in complex electronics. In such cases, professional diagnostics are required.
Critical symptoms are: a loud knocking inside the compressor (a sign of destruction of the piston group), a burning smell or scorched wiring, as well as a lack of cold when the engine is running. Attempts to disassemble the compressor or independently fill the system with freon without special equipment are prohibited and can lead to permanent breakdown of the unit.
⚠️ Attention: Opening the sealed circuit of the refrigerator requires a license and special equipment. An independent attempt to solder tubes or replace a compressor without evacuation of the system will lead to moisture ingress and immediate failure of the new compressor.
It is also worth contacting specialists if the noise is accompanied by an oil leak (oil stains are visible under the refrigerator) or if the unit stops turning off while operating in continuous mode. Professional technician will be able to accurately determine the pressure in the system and check the current motor windings and identify hidden defects.
Why did the refrigerator start making noise after defrosting?
Often after defrosting, water remains in the drainage system or on the fan blades, which when frozen turns into ice build-ups. These build-ups can hit the fan, causing a rattling noise. It is also possible that the tube was touched during washing or the compressor was dislodged. Allow the refrigerator to dry completely (24 hours) before turning it on.
Is it normal for the refrigerator to gurgle after it is turned off?
Yes, this is absolutely normal. After the compressor stops, the refrigerant in the system is under pressure and continues to flow through the tubes, equalizing the pressure. This process can take from several seconds to a minute and is accompanied by characteristic gurgling and overflowing.
Can an old refrigerator be quieter than a new one?
No, usually as mechanical parts (bearings, bushings) wear out, the noise only intensifies. If the old refrigerator suddenly begins to work quieter, this may mean that the compressor has lost power and stopped creating the necessary pressure, which leads to a deterioration in the quality of freezing.
How to lubricate the fan bearing without replacing?
If the fan is removable, you can carefully remove the sticker from the end of the motor, drop 1-2 drops of machine oil into the shaft hole and turn it several times shaft by hand. However, this is a temporary measure; It is better to replace a worn bearing with a new one, since it will still break over time.
Does the fullness of the refrigerator affect the noise level?
Yes, an empty refrigerator can be noisier due to the lack of sound-absorbing products. Products, especially those in plastic containers, dampen vibrations. However, a crowded refrigerator, where food touches the walls or interferes with air circulation, can also become a source of noise and inefficiency.