The situation when refrigerator begins to make unusual sounds always causes anxiety for the owner. Just yesterday the unit worked almost silently, but today there is an obsessive hum, knocking or periodic gurgling in the kitchen. Understanding the nature of these sounds is the first step to maintaining calm and extending the life of your household appliances.
Do not panic ahead of time. In most cases, extraneous noise does not indicate a fatal breakdown, but only indicates a violation of operating conditions or the need for maintenance. However, it is also impossible to ignore sudden changes in the sound background compressor or the circulation system.
In this article we will analyze in detail the physics of the processes inside the refrigeration chamber, we will explain the difference between normal operating noise and signs of a malfunction. You will learn to diagnose the problem yourself and understand when it’s time to call a technician, and when it’s enough to simply correct the position of the case.
Natural sounds of a working unit
Modern household appliances, even the highest quality brand models Liebherr or Boschcannot work in absolute silence. Physical processes that provide cooling of products are inevitably accompanied by acoustic effects. Knowing these nuances will help you distinguish normality from pathology.
The main source of sound is compressorwhich compresses the refrigerant and pumps it through the system. In older models with linear motors, the sound was more pronounced and monotonous. Modern inverter systems operate quieter, but it is difficult to call them completely silent, especially when starting or stopping the engine.
In addition, freon constantly circulates inside the circuit. When transitioning from a liquid to a gaseous state and back, a characteristic gurgling or transfusion of liquid is heard. This sound may become louder immediately after defrosting or loading a large volume of warm food when the system is running at full power.
⚠️ Warning: If you hear intermittent, quiet crackling sounds from the plastic, this is often caused by thermal expansion of the materials. When the temperature changes, the walls of the chamber may slightly deform, producing sounds similar to cracking.
It is also important to take into account design features. In models with the system No Frost a fan is periodically turned on, which drives cold air around the chamber. Its uniform hum is a normal situation. If the sound changes to a grinding or whistling sound, this is a signal of a problem with the bearings or icing of the blades.
Installation errors and external factors
Often the reason that the refrigerator is humminglies not in internal mechanisms, but in incorrect installation. Vibration is the main enemy of silence. If the case is unstable or touches furniture, the vibration from the running motor is transmitted to surrounding objects, amplifying many times over.
The first thing to check is the horizontal installation. Even a slight misalignment can cause the door to not fit tightly and the compressor to work with increased load. To make adjustments, use a building level and rotating supports at the bottom of the case.
☑️ Installation diagnostics
The second important point is the distance to the walls and furniture. The rear condenser grille requires free space for heat exchange. If the refrigerator is moved close to the wall, the vibration is transmitted to the building structures, and the entire wall begins to hum. The minimum gap should be at least 5-7 centimeters.
Also check that the vibrating parts of the unit do not touch adjacent cabinets or countertops. Sometimes it is enough to move the device a couple of centimeters or place anti-vibration pads under the legs to eliminate intrusive resonance.
Problems with the compressor and motor
If external factors are excluded, and the noise persists, you should pay attention to the heart of the refrigerator - the compressor. It is this node that creates the main pressure in the system. The nature of the sound here can tell an experienced diagnostician a lot.
A loud, increasing hum that turns into a knock may indicate wear on the internal parts of the engine. Over time, pistons or valves lose their geometry, clearances increase, and a shock effect occurs during operation. In such cases replacing the compressor is often the only solution.
Particular attention should be paid to the fastening elements. The rubber shock absorbers on which the motor is mounted dry out or tear over time. As a result, the metal housing of the compressor begins to vibrate against the metal frame of the refrigerator, creating a strong rattling sound.
| Type of sound | Probable cause | Urgency of repair |
|---|---|---|
| Monotonous hum | Normal or wear of bearings | Low / Medium |
| Metal knocking | Malfunction of compressor valves | High |
| Whistling or squeak | Problems with the fan or belt | Medium |
| Loud bang | Power surge or relay start | High |
In some cases, the culprit of the noise is the starting relay. If it is faulty, the compressor may try to start several times, making a characteristic click, and then hum, but not start. This is a dangerous mode that can quickly damage the motor.
Is it possible to replace the compressor yourself?
Theoretically, yes, if you have the skills to work with a blowtorch, a vacuum pump and knowledge of refilling with freon. However, in practice this is a very complicated procedure. Improper soldering of the tubes or a violation of the vacuum will lead to instant failure of the new expensive compressor. It is better to entrust this work to professionals.
Noise of the No Frost system and fans
Refrigerators with an automatic defrosting system No Frost are equipped with one or more fans. Their task is to ensure the circulation of cold air between the freezer and refrigerator compartments. It is this node that often becomes the source of specific sounds.
If you hear a uniform hum that appears and disappears, most likely the fan is working. This is fine. But if the sound turns into a crackling, grinding or loud hum, it means that frost has formed on the blades or the rotation bearings have worn out. ice, or the rotation bearings are worn out.
In winter, when the humidity in the room is high and the door is opened often, moisture gets inside and freezes on the fan parts. The blades begin to touch the layer of ice or the walls of the casing. In this case, complete defrosting of the refrigerator is required within 10-12 hours.
Sometimes the noise is caused by the fan itself being misaligned or a foreign object (for example, a piece of packaging) getting into the rotation zone of the blades. To check, it is often necessary to remove the back panel inside the freezer.
Vibration of pipelines and fasteners
The refrigerant circulation system consists of many copper tubes that run along the entire perimeter of the case. When the compressor operates, gas under pressure moves through the tubes, causing them to vibrate slightly. If the tubes are located too close to each other or touch the body, a loud metallic rattling noise occurs.
This problem can often be solved independently, without resorting to complex repairs. Carefully enough, being careful, separate the vibrating tubes with your hands (of course, with the device unplugged from the network) so that they do not touch.
It is also worth checking all visible fasteners, bolts and nuts on the back wall. From prolonged vibration they can weaken and begin to rattle. Tightening the fasteners or installing rubber washers often works wonders in terms of reducing noise levels.
⚠️ Warning: Be extremely careful when working with copper pipes on the back of the refrigerator! They are very thin and easily damaged. One careless bend or puncture will lead to a freon leak and expensive repairs with refilling.
When you need to call a specialist
There are a number of symptoms that indicate that independent actions can only do harm. If you encounter one of the following symptoms, it is better to immediately contact a service center.
Firstly, if the refrigerator makes a loud bang and then stops cooling or, conversely, freezes to the point of a glacier, this is a sign of a malfunction of the thermostat or control electronics. Secondly, if you hear a continuous metallic clanging sound that does not stop even after defrosting.
The third alarm signal is a burning smell combined with a change in the sound of the motor. This may indicate overheating of the windings or wiring problems. In such cases, operation of the device should be stopped immediately.
A professional technician will carry out diagnostics using pressure gauges and testers, accurately determine the source of noise and offer the optimal solution - from replacing rubber bands to installing a new compressor.
Noise prevention and care of equipment
So that your refrigerator pleased with silence for as long as possible, it is important to follow simple operating rules. Regular defrosting (even for the No Frost system, preventive maintenance once a year will not hurt) will help avoid the formation of excess ice on the fans.
Keep the condenser grill at the back clean. Dust and pet hair accumulated between the coils impair heat transfer. The compressor has to work harder and longer, which increases wear and noise.
Do not place the refrigerator next to heat sources (stove, radiator) and do not load it with hot foods. Sudden temperature changes force the system to work in extreme mode, which also contributes to the appearance of unnecessary sounds and reduces the service life of parts.
Does the fullness of the refrigerator affect the noise?
Yes, indirectly. An empty refrigerator changes temperature faster when the door is opened, causing the motor to turn on more often. A refrigerator full of food (especially with high water content) operates more stable and quieter, since the products act as cold accumulators.
Frequently asked questions (FAQ)
Why does a new refrigerator make more noise than the old one?
Modern models are often equipped with more powerful compressors to ensure energy efficiency class A++ and quick freezing. In addition, the lack of a thick layer of insulating foam in some budget models may dampen vibrations less well. Give the equipment 2-3 days to “break in”, often the noise level decreases.
Is it dangerous if the refrigerator hums loudly only at night?
Most likely, during the day this sound is simply lost in the general household noise. At night, in silence, the operating unit can be heard better. If the nature of the sound has not changed (no knocking or grinding), then this is a normal option. However, check if the refrigerator is not standing too close to the wall.
Is it possible to lubricate the compressor so that it makes less noise?
Absolutely not. The compressor is a sealed unit and is not intended for user service. Any attempt to drill a hole or remove the plug will lead to depressurization of the system and instant breakdown of the refrigerator.
Is gurgling in the refrigerator normal?
Yes, in 90% of cases, gurgling and liquid overflow is the sound of refrigerant (freon) moving through the evaporator and condenser tubes. This is a natural physical process, especially noticeable immediately after switching on or defrosting.
How long can an old, noisy refrigerator work?
If the noise is caused by wear on the compressor, it can work for several more years, but the risk of sudden stop is high. If the noise is caused by friction of parts (“dry”), then a breakdown can happen at any time. It is recommended to carry out diagnostics.