The unexpected appearance of extraneous sounds in household appliances often becomes a cause for concern for owners. When the refrigerator starts to actively hum, the first thing that comes to mind is the thought of a serious compressor failure or a freon leak. However, you should not rush to conclusions, since modern cooling systems are complex, and many sound effects are standard for their operation.
Understanding the physics of the process helps to distinguish normal operation from a critical failure. The refrigerant circulating through the system changes its state of aggregation as it passes through various sections of the circuit, which is inevitably accompanied by acoustic effects. In most cases, murmuring or gurgling indicates that heat exchange is occurring normally, and the refrigerant is moving through the evaporator and condenser tubes.
However, sudden changes in the sound background cannot be ignored. If a previously quiet device begins to make loud, gurgling sounds, accompanied by vibration or lack of cold, this is a signal that diagnostics are needed. In the article we will analyze in detail when noise is normal, and in which cases specialist intervention or do-it-yourself repair is required DIY repair.
Physics of the process: refrigerant circulation
The main reason why a murmur is heard in the refrigerator lies in the principle of operation of the refrigeration cycle. Freon, under pressure, moves along a closed loop, passing from liquid to gaseous state and back. When liquid refrigerant enters a low-pressure zone (evaporator), it begins to boil at low temperatures, which visually and acoustically resembles boiling water.
This process is accompanied by a characteristic sound, which users often describe as “water pouring” or “murmuring”. It is heard especially clearly immediately after the compressor stops. At this moment, the pressure in the system equalizes, and the remaining liquid freon flows down the tubes, creating gurgling sounds. If your refrigerator is operating in normal mode, such sounds should be periodic and not too loud.
⚠️ Attention: If the murmur is accompanied by a constant hum of the compressor without shutting off, this may indicate a refrigerant leak or incorrect operation of the thermostat, which requires immediate inspection.
The intensity of the sound depends on the type of refrigerant used and the design of the system. In models with No Frost air circulation also makes its own adjustments, but the main “musical” background is created by the movement of the working fluid in the lines. It is important to listen to the nature of the sound: uniform pouring is good, but chaotic gurgling with “spitting” can be an alarming symptom.
Is this normal: when the noise is normal work
Many owners of new equipment are scared when they hear the refrigerator “talking”. Manufacturers of household appliances often indicate in their instructions that certain sound effects are acceptable. The key factor here is operation cycle the aggregate. The sounds are most intense at the moments of starting and stopping the engine, as well as during periods of active gas circulation.
The process can be especially loud in models with inverter compressors or in two-compressor systems, where the synchronization of the circuits creates a complex acoustic picture. If you hear liquid flowing in the refrigerator, but the temperature in the chambers remains stable, and there is no excessive ice on the walls or, conversely, a complete lack of cold, then most likely the equipment is working.
It is also worth considering the case material and the quality of sound insulation. In budget models, thin walls can act as resonators, enhancing the natural sounds of the mechanisms. If the unit is placed close to a wall or furniture, the sound may be reflected and appear louder than it actually is. Checking the installation and the distance to the walls is the first step in diagnosis.
No Frost system and fan operation
In refrigerators equipped with the system No Frost (or "Showcase"), in addition to the compressor, a fan operates, providing forced air circulation. Sometimes users confuse the sound of a fan with the bubbling of liquid. However, in such systems there is another source of sounds - the defrosting process.
During the defrost cycle, the ice accumulated on the evaporator melts. The water drains into a drain pan located above the compressor. Drops of water falling onto a hot compressor casing or pan may create a distinct hissing or gurgling sound. This is absolutely a normal process, indicating that the defrost system is functioning correctly.
- 🌬️ Fan: A uniform hum or whistle, depending on the speed of rotation of the blades.
- 💧 Drainage: The sound of dripping or flowing water during or immediately after defrosting.
- ❄️ Cracks: The plastic of the chamber may crack slightly due to temperature changes, which is often mixed with the general background noise.
If the sound resembles someone rinsing in the refrigerator bottle of water, and this happens all the time, it is worth checking whether the drainage channel is frozen. A blockage in the water drainage system can lead to the accumulation of moisture inside the case, which then begins to actively move when the fan operates, creating abnormal sound effects.
Clogging capillary tube: when cleaning is needed
One of the technical reasons for a change in the nature of the sound may be partial clogged capillary tube. This is a thin copper tube in which throttling (a sharp drop in pressure) of the refrigerant occurs. If there is moisture or oil breakdown products in the system, they can form ice or oil plugs.
When clogged, freon has difficulty passing through a narrow cross-section, which causes a characteristic hissing or whistling that turns into gurgling. The pressure in the system is disturbed: at the entrance to the evaporator it may be normal, but the permeability is reduced. This leads to the compressor working with increased load, trying to push the refrigerant, and the sound becomes more intense and shrill.
Diagnosing a blockage at home is difficult, as it requires measuring the pressure in the circuit and analyzing the operation of the compressor. If you notice that the refrigerator has begun to work longer than usual, the freezer is not freezing well, and the sound has changed to a whistling-gurgling sound, the problem probably lies in the line.
Is it possible to clean the tube yourself?
Cleaning the capillary tube yourself requires special equipment (press, nitrogen, vacuum pump) and skills rations. Trying to purge the system with your mouth or a spray can is ineffective and dangerous. You need to call a technician to vacuum and replace the filter-drier.
Faults of the compressor and shock absorbers
The compressor is the heart of the refrigerator, and any changes in its operation are reflected in the background sound. If shock absorberson which the motor-compressor is suspended are worn out or weakened, vibration is transmitted to the housing and tubes. As a result, the tubes begin to vibrate against each other or against the walls of the cabinet, creating rattling, which can be disguised as gurgling.
It is also worth paying attention to the condition of the motor itself. Worn internal valves or bearings can cause knocking and gurgling sounds inside the crankcase. If the sound comes directly from the black “tank” at the back of the refrigerator and is accompanied by strong vibration, the compressor may be reaching the end of its life.
| Sound type | Probable cause | Need for repair |
|---|---|---|
| Quiet overflow | Freon circulation | Not required (Normal) |
| Loud gurgling + puddle | Clogged drainage | Cleaning the drainage hole |
| Whistling and hum | Clogged capillary tube | Requires a technician (flushing) |
| Metal knocking | Wear of the compressor | Replacement of the compressor |
| Rattling of tubes | Vibration of communications | Adjusting the position of tubes |
It is important to distinguish between the sound of a running motor and the sound of gas movement. The motor hums evenly. If metallic clangs or sharp clicks are added to the hum, this is a sign of mechanical damage to the internal components of the unit.
Errors during installation and operation
Often the cause of "murmuring" is trivial errors when installing equipment. If the refrigerator is not level, the refrigerant may be unevenly distributed throughout the system, creating air pockets or active boiling zones in the wrong places. Checking the horizontal installation is the first thing to do.
It is also worth checking whether the tubes coming from the compressor are touching each other or the cabinet walls. They vibrate when in use, and metal-on-metal contact creates a resonating sound. Sometimes it is enough to gently push the tubes apart with your hand (with the device turned off!) or a stick to eliminate noise.
- 📏 Level: Use a building level to check the installation horizontally and vertically.
- 🔧 Tubes: Make sure that the copper lines do not touch or vibrate case.
- 🧊 Loading: Too much food can block the air flow, causing the fan to work harder.
⚠️ Attention: Never tilt the refrigerator more than 40 degrees while it is running. This can lead to oil from the compressor entering the cooling circuit, which will cause water hammer and equipment failure.
☑️ Noise diagnostics
When it is necessary to call a specialist
There are a number of symptoms in which independent actions are not only useless, but also dangerous. If the murmur is accompanied by a complete absence of cold, the appearance of an unpleasant chemical odor or visible oily spots under the refrigerator, these are signs of a freon leak or depressurization of the system. In such cases, operation cannot be continued. The refrigerant may be flammable or toxic, and running the compressor without proper gas circulation will cause it to overheat and burn out. You also need the help of a professional if you hear the sound of a “working boiler” for a long time without stopping. Freon leakage or system depressurization.
In such cases, operation cannot be continued. The refrigerant may be flammable or toxic, and running the compressor without proper gas circulation will cause it to overheat and burn out. You also need professional help if you hear the sound of a “boiler running” for a long time without stopping.
The technician will conduct diagnostics using a pressure gauge station, check the current consumption of the compressor and, if necessary, evacuate the system and charge it with new refrigerant. Repairing a cooling system is a complex technical process that requires special tools.
Why does the refrigerator hum loudly immediately after turning on?
This is a normal situation. At the moment of startup, the compressor creates maximum pressure, and the refrigerant begins to actively circulate through the system. Liquid fractions of freon noisily pass through the capillary tube and choke, entering the evaporator. After 10-15 minutes, when the system returns to operating mode, the sound should become quieter and more uniform.
Can murmurs be a sign that the refrigerator has defrosted?
Yes, if we are talking about the sound of flowing water. When the No Frost system defrosts or when the “coat” melts in the drip system, water flows into the drain. If the drain hole is clogged, water may gurgle inside the chamber or under the casing. Check the hole for water drainage on the back wall inside the refrigerator compartment.
Does the brand of the refrigerator affect the noise level?
Absolutely. Models Bosch and Liebherr are traditionally considered quieter due to high-quality sound insulation and expensive compressors. Budget models, such as some series Indesit or Biryusa, may be noisier due to design features and less effective vibration dampers. However, even a quiet refrigerator can begin to make noise if it malfunctions.
What to do if the sound appears after transportation?
If the refrigerator was transported lying down or tilted strongly, the oil took time to drain back into the compressor. It is recommended not to plug in the device for at least 4-8 hours (or better yet, 24 hours) after delivery. If you turn it on earlier, the compressor may run dry or with oil in the circuit, which will cause noise and damage.
Is this dangerous for products?
Sound itself is not dangerous for products. What's dangerous is what's behind that sound. If due to a malfunction (clogging, leakage) the temperature in the chambers rises above normal, the food may spoil. Therefore, if the noise seems unnatural to you, be sure to check the temperature with a thermometer.