An unexpectedly loud sound from a refrigerator can unsettle any owner. Constant hum, periodic knocking or strange gurgling is not just acoustic discomfort, but also a potential signal of serious problems in the operation of the unit. Ignoring these symptoms can lead to failure of expensive components or damage to products.
In this article we will examine in detail why compressor or other elements of the system produce extraneous noise. You will learn to distinguish normal operating sounds from signs of breakdown, and also learn what actions you can take on your own to reduce the noise level without calling a technician.
Understanding the nature of the sound is the first step to solving the problem. Vibration, humming or whistling have different causes, and for each of them there is its own diagnostic algorithm. Let's figure out how to determine the source of the problem and return silence to the house.
Natural sounds of the refrigerator compartment
Before you panic and look for a service center phone number, it is worth remembering that any refrigeration unit is a complex mechanism with moving parts and circulating fluids. During normal operation, the device will inevitably produce sounds, which may vary depending on the model and manufacturer. For example, modern systems No Frost often operate louder than older models with drip defrosting due to the presence of additional fans.
One of the most common sounds is the quiet bubbling or pouring of liquid. This happens when refrigerant (freon) moves through the pipes of the system, changing its state of aggregation. After the compressor is turned off, this sound may persist for several minutes until the pressure in the system equalizes. It is also normal to periodically click the thermostat, which regulates the temperature inside the chambers.
⚠️ Attention: If you hear a loud bang or a cracking sound, similar to a gunshot, immediately after turning the device on or off, this may indicate thermal expansion of the plastic or metal case. Although this is not a malfunction, such sounds often frighten users.
It is important to be able to distinguish between background operating hum and intrusive, annoying noise. Normal sound level for most household models it ranges from 25 to 40 dB. If the sound suddenly changes its tone or becomes much louder than usual, you should listen more carefully.
Problems with installation and external factors
Often the reason why the refrigerator is hummingis not internal at all breakdowns, but installation errors. Vibration from a running motor is transmitted to the body, and then amplifies (intensifies) upon contact with the floor or walls. If the appliance is not level, the load on the legs is distributed unevenly, which causes rattling.
The first thing to do is check the horizontal installation. To do this, you can use a building level or simply shake the body. Adjusting the height of the legs helps eliminate distortions. It is also worth making sure that there is a gap for ventilation between the back wall of the unit and the wall of the room, otherwise compressor it may overheat and work with increased load.
Contact with furniture is another common source of noise. If the refrigerator is moved close to the kitchen unit, the vibration is transmitted to the cabinets, causing them to resonate. It is enough to move the equipment a few centimeters for the sound to disappear.
☑️ Diagnostics of refrigerator installation
Sometimes foreign objects that are under or behind the refrigerator may fall into the fan operating area or simply rattle from vibration. Check the area around the unit for bottles, boxes or tools.
Faulty compressor and start relay
The heart of any refrigerator is compressor. It is this that ensures the circulation of refrigerant throughout the system. If this unit is faulty or worn out, it begins to emit characteristic sounds: a loud hum, knocking or humming, which does not stop even in standby mode.
One of the common causes of noise is failure start relay. This small element is responsible for starting the engine. If the relay is stuck or burnt out, the compressor may hum but not start, or make a loud clicking noise when trying to start. In such cases, it is often necessary to replace the relay, which is a relatively simple procedure.
If the compressor itself is mechanically worn out (for example, broken bearings or valves), the sound will be metallic and rumbling. In this case, simply replacing parts may not help, and the entire motor-compressor will need to be replaced.
How to check the serviceability of the compressor?
Unplug the refrigerator. Remove the back cover and locate the compressor. Carefully remove the start relay housing (it is usually black and attached to the side). Shake the relay: if you hear the ball inside, it means it is broken and needs to be replaced. If the relay is intact, but the compressor hums and does not start, the problem may be in the motor itself or the windings.
You can also use a multimeter for diagnostics by checking the resistance of the windings. However, if you do not have experience working with electrical appliances, it is better to entrust this task to a professional, since high voltage it is life-threatening.
Fan noise in No Frost systems
In refrigerators with the system No Frost Fans are responsible for circulating cold air. Over time, dust can get into the fan motor bearings, or they simply wear out and lose lubrication. This leads to a hum, howl or crackling sound.
Another common problem is ice freezing on the fan blades or on the walls of the evaporator. In this case, the blades touch the ice crust, producing a characteristic crackling or knocking sound. This often occurs due to a leak in the door seal or a malfunction of the defrost heating element.
To eliminate noise caused by ice, sometimes it is enough to completely defrost the refrigerator (leave it off for 24 hours). If the problem is a worn bearing, the fan will need to be replaced.
| Sound type | Probable cause | Solution method |
|---|---|---|
| Monotonous hum | Bearing wear compressor | Replacing the compressor |
| Crackling or knocking | Ice on the fan | Defrost (24 hours) |
| Humming without starting | Malfunction of the starting relay | Replacement of the relay |
| Whistling or howling | Fan (bearings) | Lubrication or replacement |
It is worth noting that in some models Indesit or Ariston fans can be located in the upper part of the freezer compartment, and access to them requires partial disassembly of the internal space.
The influence of the quality of the refrigerant and pipelines
If the refrigerator makes sounds similar to gurgling, pouring water or hissing, this is most often due to movement Freon through the system. In most cases this is normal, but if the sound becomes too loud, it may indicate a refrigerant leak or a clog in the capillary tube.
When freon leaks, the pressure in the system drops, and the compressor begins to work with overload, trying to reach the desired temperature. This is accompanied by a change in the sound background: the humming becomes more strained and prolonged. Freon leakage is often accompanied by a lack of cold in one of the chambers when the engine is running.
A clogged system also changes the nature of the circulation. Refrigerant cannot flow freely through tight spaces, causing whistling or hissing. In such cases, professional cleaning of the system and refilling with new refrigerant is required.
⚠️ Attention: Freon is a gas that can be dangerous under certain conditions. Independently soldering the tubes or attempting to refuel without evacuating the system is strictly prohibited and can lead to an explosion or damage to the compressor.
In addition, the vibration of the tubes themselves, if they are poorly secured or touch the housing, can create a rattling sound. Carefully bending the tubes or installing additional dampers helps solve this problem.
Vibration of internal elements and dishes
Sometimes the source of noise turns out to be trivially simple. Bottles, cans, or plastic containers may rattle inside the refrigerator if they are placed unsteadily or touch each other. Vibration from the compressor is transmitted to the shelves, causing their contents to “dance” and knock.
It is also worth checking the fastenings of the shelves and drawers. If the plastic holder is cracked or loose, it will make an unpleasant sound every time the motor cycles on and off. Inspect the drawer slides; they can sometimes slip or become warped.
Do not forget that an empty refrigerator can make more noise than a full one. Food and water bottles work as additional sound absorbers and temperature stabilizers, reducing the frequency of compressor starts.
When you need to call a specialist
There are a number of situations when self-repair is not only ineffective, but also dangerous. If you hear a loud metallic knock, smell a burning smell or smoke, or the refrigerator stops freezing while the motor is running, immediately unplug the appliance.
Complicated cases requiring specialist intervention:
- 🛠️ Replacement compressor: requires special equipment for pumping out freon and evacuating the system.
- ❄️ Fixing the leak: you need to find the leak, solder it and refill the system.
- 💻 Malfunction electronics: if the problem is in the control module (board), professional diagnostics and resoldering of the elements are required.
- 🔧 Replacing the evaporator: often requires disassembling the case and foaming.
An attempt to independently eliminate these malfunctions can lead to the final failure of the equipment. The cost of repairs in this case will increase significantly.
It is also important to consider the age of the equipment. If your refrigerator is more than 10-12 years old and it has begun to make strange noises, repairs may not be economically feasible compared to purchasing a new, more energy-efficient model.
Noise prevention and extending service life
In order for the refrigerator to operate quietly and for a long time, you must follow simple operating rules. Regular defrosting (even for No Frost systems, preventative defrosting is recommended once a year) helps avoid the formation of ice jams and reduces the load on the compressor.
Keep the condenser clean (grids on the back). Dust and animal hair that accumulate there impair heat transfer, causing the engine to run longer and louder. The condenser should be vacuumed every 6-12 months.
Checking the door seals is another important point. If the rubber band does not fit tightly, warm air enters the chamber, which forces the refrigerator to work in increased mode. Wipe the seal with a soft cloth and check its elasticity.
Is it possible to lubricate the compressor if it starts to make noise?
Self-lubrication of the compressor is impossible, since it is a sealed unit. Attempting to drill oil holes will result in depressurization and failure. If the bearing inside the compressor is noisy, the unit must only be replaced.
Why is a new refrigerator noisier than the old one?
Modern models often use more powerful compressors and fans to ensure class A++ energy efficiency. In addition, sounds resonate more strongly in an empty case. Give the equipment 2-3 days to “grind in” and fill the chambers with products.
Is it normal if the refrigerator makes the sound of a bursting bubble?
Yes, this is normal. The sound resembles a crackling or bursting of bubbles and is caused by thermal expansion of the plastic parts of the inner box as the temperature changes. This is not a sign of a malfunction.
How to reduce the noise of a refrigerator if it is in a kitchen studio?
Use anti-vibration pads under the legs, make sure that the equipment does not touch the walls. You can install additional soundproofing panels on the back wall of the niche, but do not block the ventilation openings.
Following these recommendations will help you maintain a quiet home and extend the life of your refrigerator. Remember that careful attention to the “voice” of your equipment allows you to prevent serious breakdowns at an early stage.