The purchase of new household appliances is always accompanied by the expectation of comfort and silence, but in the first hours of operation, owners often encounter unexpected sounds. The question of why the refrigerator makes noise when it is first turned on is one of the most common among those who have just completed installation of the equipment. Modern units are equipped with powerful compressors and complex refrigerant circulation systems, which inevitably leads to acoustic effects that may seem alarming to an inexperienced user.
It is important to understand that first launch is fundamentally different from the normal operation of the device after entering the mode. During this period, the tubes are actively filled with freon, the internal chambers are intensively cooled to the specified temperatures and the pressure in the system is stabilized. It is these physical processes, accompanied by the expansion of materials and the movement of gases, that often become the source of hum, gurgling or crackling, which frighten the owners, but in most cases are absolutely normal.
In this article we will analyze in detail the physics of the processes occurring inside refrigerator compartment and the freezer, we will explain the difference between acceptable operating noise and signs of malfunction. You will learn which sounds should alert you and which indicate the correct operation of the unit, and also receive a step-by-step algorithm of actions to minimize acoustic discomfort.
Physics of the first start: what happens inside the system
The moment the refrigerator is turned on to the electrical network marks the beginning of a complex thermodynamic cycle. The compressor, which is the “heart” of the device, starts working at maximum speed in order to cool the internal volume as quickly as possible to the temperatures specified by the factory settings or the user. It is at this moment that noise level can be significantly higher than usual, since the engine runs without interruption until the target point is reached.
Simultaneously with the operation of the motor, active movement of the refrigerant along the circuit begins. Freon, passing from liquid to gaseous and back, passes through narrow capillary tubes and an expansion valve. This process is often accompanied by a characteristic sound, reminiscent of gurgling water or the transfusion of liquid. Many users mistake this for a leak or malfunction, although in fact this indicates normal circulation of the working fluid in the system.
In addition, it is worth considering the thermal expansion of materials. Plastic panels, metal shelves and the inner walls of the chamber contract or expand when the temperature changes sharply. This movement is often accompanied by clicks, crackling sounds or sounds similar to shooting. Thermoregulator During this period it also works intensively, constantly closing and opening the circuit, which adds its own acoustic effects to the overall sound picture.
Noise level standards and technical characteristics
To objectively assess the situation, it is necessary to rely on technical standards. Manufacturers of household appliances are guided by strict standards regarding permissible sound pressure levels. For modern refrigerator models, noise levels in the range from 34 to 42 decibels (dB) are considered normal when operating in normal mode. However, when first turned on, when the system is operating at maximum load, this figure may temporarily exceed the declared values.
It is worth distinguishing between the types of sounds produced. The hum associated with compressor vibration is usually low frequency and constant. The sounds of freon circulation are intermittent and gurgling. It is important to understand that inverter compressorswhich have been gaining popularity in recent years, operate much quieter than traditional linear models, but they can also produce specific high-frequency sounds at startup.
| Sound type | Probable reason | Is this normal? |
|---|---|---|
| Uniform hum | Compressor operation | Yes, if not louder than 45 dB |
| Gurgling, gurgling | Freon circulation | Yes, absolutely normal |
| Crackling, clicking | Thermal expansion of plastic | Yes, goes away after cooling |
| Metal ringing | Vibration of pipes or dishes | No, requires elimination |
If you notice that the sound is much louder than stated in the device passport, or it is of an irritating, ear-piercing nature, this may indicate a violation of transportation rules or a manufacturing defect. However, during the first 6–12 hours of operation, increased acoustic activity is allowed.
The influence of transportation and installation on acoustics
Often the cause of excessive noise is not internal failure, but incorrect installation or the consequences of careless transportation. If the refrigerator was shaken violently during delivery, tilted at an angle of more than 40 degrees, or transported lying down, oil from the compressor may have entered the refrigerant circuit. When first started, the compressor tries to pump this mixture, which causes hydraulic hammer and a lot of noise.
⚠️ Attention: If the refrigerator was transported lying down, it is strictly forbidden to turn it on immediately. Leave it in an upright position for 12–24 hours to allow the oil to completely drain back into the compressor crankcase. Switching on earlier than this may lead to jamming of the piston group.
The second critical factor is the geometry of the installation. The refrigerator must stand strictly horizontally. If the legs are not adjusted correctly, the housing will warp, resulting in improper load distribution on the compressor and increased vibration. The sound in this case is transmitted to the floor and walls, creating a resonating effect that is perceived as very loud.
It is also worth checking the distance to the walls and furniture. To operate efficiently and reduce noise, the system requires free air flow. If the refrigerator is moved close to the wall, the ventilation grilles can create a whistling sound due to the passage of air, and vibration of the housing will be transmitted to building structures.
Design features: inverter versus conventional compressor
The nature of the noise directly depends on the type of engine installed. Traditional linear compressors work on the “start-stop” principle: they turn on at full power, cool the chamber to the desired temperature and turn off. When starting and stopping, such motors emit a characteristic click and a short-term hum, which can be quite loud.
In contrast, inverter systems work constantly, but with variable power. They do not make loud startup sounds, as they gradually gain momentum. However, at the first start-up, when it is necessary to sharply cool a large volume of warm air, the inverter compressor can operate at extreme frequencies, emitting a high-frequency whistle or hissing that is unusual for hearing.
Why can the inverter hum?
Inverter systems compressors are sensitive to voltage fluctuations. If your network voltage is unstable, the control unit can adjust the operation of the motor, causing changes in the tone of the hum. This is not a malfunction, but it is recommended to use a stabilizer to prolong service life.
It is important for users to know the type of equipment they have in order to correctly interpret sounds. If the instructions indicate the presence of a system No Frost, then another source of noise will be added - fans that pump in cold air. When first turned on, they can work more intensely, creating an air flow that is audible inside the chambers.
Proper installation algorithm to minimize noise
To eliminate external factors that increase noise, it is necessary to install the unit correctly. This process does not require special tools, but requires care and consistency of actions. Ignoring simple installation rules often results in a working refrigerator humming louder than its old counterpart.
☑️ Checking the installation of the refrigerator
The first step should always be to check the horizontal position. Use a spirit level to place it on the top panel and doors. Adjustment is carried out by unscrewing or tightening the front support legs. The back legs are usually non-adjustable, so the main emphasis is on the front.
Next, make sure that the refrigerator does not touch the wall, cabinets or other objects. Vibration transmitted through contact points amplifies the noise many times over. There should be a gap of at least 5–10 cm between the back wall of the refrigerator and the wall of the room for free air circulation and vibration damping.
Alarming symptoms: when you need to call a technician
Despite the fact that the first start-up is often accompanied by noise, there are signs that clearly indicate a malfunction. If you hear a loud metallic clanging, grinding or knocking sound similar to hammer blows, this may indicate mechanical damage to the compressor or a foreign object has entered the housing.
⚠️ Attention: If after 12-24 hours of continuous operation the noise level does not decrease and the temperature in the chambers does not drop, immediately unplug the device. Prolonged operation of a faulty compressor can lead to its complete failure and costly repairs.
A humming sound, which is accompanied by a burning or plastic smell, should also alert you. This may indicate overheating of electrical components or melted insulation. In such cases self-repair is prohibited, you must contact an authorized service center for diagnostics.
Another sign of a problem is if the refrigerator makes loud sounds only at certain moments, for example, when opening the door or when you touch the body with your hand. This may indicate a voltage breakdown on the housing or a grounding fault, which is life-threatening.
Practical tips for reducing noise levels
If the refrigerator is technically working, but the noise level still causes discomfort, you can use a number of simple methods to reduce it. Often the problem lies in the resonance of objects located nearby or inside the unit. Check to see if bottles of liquid on the door or pots on the shelves are vibrating.
Use anti-vibration pads under the support legs. Special rubber mats or thick felt pads will help dampen vibrations transmitted to the floor. This is especially true for houses with thin ceilings or wooden floors.
Regularly inspect the interior space. Make sure all drawers and shelves are securely in place. Play in plastic elements can create rattling noise when the system fans operate. No Frost.
Frequently asked questions (FAQ)
How long can a refrigerator hum loudly when first turned on?
Usually the period of active operation and increased noise lasts from 6 to 12 hours. This time is necessary for the initial freezing of the chambers and stabilization of the temperature regime. If the noise does not subside after a day, it is worth checking the installation.
Is it normal that you can hear the gurgling of freon?
Yes, the sounds of overflowing liquid, gurgling and hissing are absolutely normal for a working refrigeration system. They indicate the circulation of refrigerant through the tubes of the evaporator and condenser.
Is it possible to reduce the volume of the hum by software?
In most household models, only the temperature, but not the noise level, is controlled by software. However, some premium models have a “Night” or “Silent” mode, which limits the maximum power of the compressor, which indirectly reduces noise.
Does a full load of food affect the noise when first started?
Yes, an empty refrigerator may be noisier due to the lack of sound absorption by the food. However, when turning on for the first time, it is not recommended to load the chambers with food before entering the mode, so as not to create unnecessary load on the compressor.