It's deep night, silence reigns in the house, and it is at this moment that you notice an intrusive, annoying sound coming from the kitchen. The refrigerator makes noise at night much stronger than during the day, and this is not a coincidence, but a physical pattern. During the day, the background noise of household appliances, street traffic and conversations masks the operation of the compressor, but at night even the slightest hum becomes audible and can disturb a restful sleep.
Understanding the nature of this sound is the first step to solving the problem. Modern models techniques, especially with system No Frost, are equipped with many mechanical components, each of which makes sounds during operation. However, there is a fine line between a normal operating hum and a sign of an incipient malfunction that requires the intervention of a technician.
In this article we will analyze in detail which sounds are normal and which signals a breakdown. You will learn to independently carry out initial diagnostics, distinguish casing vibration from problems with compressor and understand when it is necessary to call a repair specialist.
Physics of night noise: why during the day quieter, but louder at night?
The main reason why the refrigerator runs loudly at night lies in the acoustic background of the room. During the day, the sound pressure level in the apartment is much higher due to external factors. At night, when the city and households quiet down, human hearing becomes more susceptible to low-frequency hums.
In addition, it is worth considering the temperature regime of the compressor. At night, the ambient indoor air temperature is usually lower than during the day, especially if air conditioners are running or windows are open. This can affect the viscosity of the coolant oil in the system, changing the nature of the sound when starting the engine.
It is also important to understand the principle of operation of the thermostat. If you often open the door during the day to let in warm air, the compressor will turn on frequently, but for short periods of time. At night, when the door is closed, the unit may turn on less often motor-compressor, but for longer cycles, which makes each start more noticeable and lasting.
Normal sounds: what is the normal operation of the unit
Before you panic and look for the number service center, you need to make sure that the sounds emitted belong to the normal category. Inverter compressors older models may sound different, but a number of sounds are acceptable for any equipment.
First of all, this is the sound of a working compressor. It can be smooth and low, reminiscent of the hum of a transformer. Also considered normal is periodic turning on and off of the engine, accompanied by a clicking sound. This click can be quite loud, especially in older models. start-up relay. This clicking noise can be quite loud, especially on older models.
Particular attention should be paid to sounds associated with refrigerant circulation. The flowing liquid produces a characteristic gurgling, hissing or sound of pouring water. This is absolutely normal for the system No Frost and drip defrosting, since freon moves through the tubes of the evaporator and condenser.
- 🔊 Uniform humming of the motor without sudden changes in tone.
- 💧 Quiet gurgling or pouring of liquid inside the housing after stopping compressor.
- ⚡ Single or double click when starting or stopping the engine.
- 💨 Quiet fan noise (in models with the system No Frost).
Why are sounds heard at night?
At night, the room temperature often drops, which can slightly change the acoustic properties materials of the case and pipes, making the resonance more noticeable. In addition, in silence, our brain focuses on any extraneous stimuli.
Mechanical reasons for increased sound: vibration and installation
If you are sure that the refrigerator was previously quieter, or the sound has changed its character, becoming more rattling, the problem may lie in the mechanics. The unit must stand strictly horizontally, resting on all four legs.
Check that the refrigerator body does not touch the walls of the kitchen unit or adjacent objects. Even a minimal gap of a few millimeters can create a resonance, which increases. vibrationWhen the compressor operates, the housing vibrates slightly, and if it comes into contact with the furniture, this vibration is transmitted to it, creating. loud hum.
Another source of problems is transportation bolts. Sometimes in new models they forget to remove the fixing elements from the rear panel or inside the compressor compartment. They can cause severe vibration and knocking when the engine is running.
☑️ Installation diagnostics. refrigerator
It is also important to check the condition of the floor. If the covering is soft (carpet, linoleum with a foam base), the legs may fall through, compromising stability. In this case, it is recommended to place special anti-vibration stands or hard plates under the legs.
⚠️ Attention: Never leave them. the refrigerator is in an inclined position for a long time. This can lead to oil flowing from the compressor into the refrigerant circulation circuit, which can lead to failure of the compressor motor motor-compressor.
Problems with the defrosting system and fans
In modern models with the system No Frost Fans are responsible for air circulation. Over time, their bearings can wear out, which will lead to a howling, hum or crackling noise. At night, in silence, this sound becomes especially clear.
The noise can also be caused by ice freezing on the fan blades or on the elements of the defrosting system. data-i="109">the defrost timer is faulty or the defrost timer is not working correctly, the ice may build up to such an extent that it begins to touch the rotating parts. defrosting heating element faulty or the defrost timer is not working correctly, ice may build up to the point that it touches the rotating parts.
The nature of the sound when there is a problem with the fan usually changes: it appears and disappears, and may be accompanied by a grinding noise. In some cases, the fan may jam, and then you. hear the strained hum of the motor trying to turn the blades.
| Sound type | Probable cause | Characteristic signs | Urgency of repair |
|---|---|---|---|
| Monotonous howling | Fan bearing wear | The sound increases over time, does not depend on the compressor cycle | Average |
| Crackling or knocking | Ice on blades | Appears periodically, often after defrosting | High (risk of fan failure) |
| Humming with vibration | Imbalance of the impeller | Vibration is transmitted to the body | Medium |
Faults in the compressor and starter. relay
The most serious and expensive cause of noise is a malfunction of the very heart of the refrigerator, compressor. If the unit makes loud metallic knocks, clanging or a very loud, strained hum that can be heard even through a closed kitchen door, this is an alarming signal. data-i="135">. This small element is responsible for starting the engine. If it is faulty, the compressor may try to start, make a loud clicking noise, hum for a few seconds, and then shut off again. Such cycles can be repeated endlessly.
Often the problem lies in start-protection relay. This small element is responsible for starting the engine. If it is faulty, the compressor may try to start, make a loud clicking noise, hum for a few seconds, and then shut off again. Such cycles can be repeated endlessly.
Wear of the internal mechanisms of the compressor (valve group, piston system) also leads to increased noise. In older models, this is often accompanied by a drop in performance - the refrigerator freezes worse, but works almost non-stop.
⚠️ Attention: If you hear a loud metallic knock inside the compressor, immediately unplug the appliance. Further operation may lead to complete jamming of the engine and impossibility of recovery.
Diagnostics of the compressor requires special skills and tools. However, you can visually assess the condition: if the tubes coming from the motor vibrate strongly and hit each other or the housing, they need to be carefully separated or secured with clamps.
The influence of fullness and location of products
Sometimes the source of noise is not the mechanisms, but the products themselves. If bottles or glass jars are placed close to each other or touching the sides of the refrigerator, they will make ringing and rattling noises when the shelves vibrate. At night, the sound can be deafening.
Check shelves and drawers. Plastic elements may dry out or crack, causing them to no longer fit tightly in the grooves. When the fan operates or the compressor vibrates, loose parts begin to rattle.
It is also worth paying attention to how the refrigerator is loaded. Packing that is too dense can interfere with air circulation, causing the fan to work harder, which increases noise levels. An empty refrigerator may also make more noise due to the lack of sound-absorbing properties of the products.
- 🥤 Remove glass containers from the walls and from each other.
- 🧊 Check the tightness of the drawers and shelves.
- 🍖 Do not fill the unit completely, leave gaps for air.
- 🧱 Use shelf seals if they are loose.
When you need to call a technician: critical symptoms
There are a number of symptoms in which self-repair is not only ineffective, but also dangerous. If the refrigerator hums intermittently, constantly turns on and off, or emits a burning smell, this is a reason to immediately contact a professional.
It is especially dangerous to ignore problems with the electrical part. If you notice sparking in the compressor area or melted wires, use of the device should be stopped. You should also be wary if the refrigerator has stopped freezing, but is very loud.
In the event of a refrigerant (freon) leak, you may hear a hissing sound, but more often this is indicated by the lack of cold when the engine is running. Independent refueling or leak detection requires specialized equipment and knowledge.
⚠️ Attention: Do not attempt to disassemble the sealed circuit yourself or change the compressor without the appropriate qualifications. This can lead to injuries and final breakdown of the equipment.
Is it possible to lubricate the compressor?
Lubricating the internal parts of the compressor at home is impossible. If the noise is caused by friction inside the motor, only replacing it will help.
Noise prevention: how to extend the life of a refrigerator
In order for your refrigerator to enjoy silence for as long as possible, it is important to follow the operating rules. Regular defrosting (for models without No Frost) prevents the build-up of excess ice, which creates a load on the compressor.
Keep the condenser on the back wall clean. Dust and animal hair that accumulate on the grille impair heat transfer, causing the motor to work harder and louder. Wipe the back panel with a dry cloth every six months.
It is also important to control the temperature in the room. Installing a refrigerator next to a radiator, stove, or in direct sunlight causes it to work in extreme mode, which accelerates wear of parts and increases noise levels.
The result of proper operation will be not only silence in the house, but also significant savings on electricity and repairs. Remember that prevention is always cheaper and easier than restoration after a breakdown.
Frequently asked questions questions (FAQ)
Why is the new refrigerator noisier than the old one?
Modern models are often equipped with more powerful compressors and ventilation systems No Frostwhich can be louder than the old Soviet counterparts. In addition, new models use less sound-deadening materials to save weight and cost. Usually, after a couple of weeks of operation, the noise may decrease.
Is it normal for the refrigerator to gurgle after being turned off?
Yes, this is absolutely normal. After the compressor stops, refrigerant continues to flow through the system under the influence of pressure differences and gravity, which causes the sounds of overflowing liquid. This process can last from a few seconds to a couple of minutes.
Can a refrigerator make noise due to power surges in the network?
Yes, unstable voltage can cause humming of transformers and incorrect operation of the motor, which increases the noise. To protect equipment and reduce noise levels, it is recommended to use a voltage stabilizer or surge protector.
What to do if the refrigerator is on a crooked floor?
In this case, it is necessary to level the unit using adjustable legs and a building level. If the legs do not allow you to achieve an ideal horizontal position, place hard, non-deformable pads under them (for example, pieces of linoleum or special anti-vibration plates).