The situation when the refrigerator began to hum unusually loud is familiar to many owners of household appliances. In the silence of a night apartment, this sound can seem deafening, causing irritation and concern about the condition of the unit. Most often, the source of vibration and low-frequency hum is the motor-compressor, which is the heart of the cooling system.
It is important to understand that completely silent refrigerators do not exist in nature, since the physics of gas compression and the movement of pistons inevitably creates acoustic vibrations. However, if noise level its character has sharply increased or changed, this cannot be ignored. In some cases, this is a signal that the unit is operating under increased load or has mechanical defects.
Before calling a technician, it is worth conducting an initial diagnosis yourself. Often the reason for this is trivial things that do not require complex repairs. In this article we will analyze in detail all possible causes, from incorrect installation to serious damage to internal components. The compressor is humming, things become banal and do not require complex repairs. In this article we will analyze in detail all possible causes, from incorrect installation to serious damage to internal components.
Is it a normal operating hum or a sign of a malfunction?
The first thing to start with is determining the type of sound. Modern models are equipped with inverter motors, which operate almost silently, while older units with linear compressors always emit a characteristic hum when starting and operating. If your refrigerator emits a smooth, monotonous sound that either dies down or resumes cyclically, most likely this is normal operation.
The alarm should be sounded if the nature of the sound changes to intermittent, shrill, or is accompanied by knocking. If the hum is accompanied by vibration of the housing, which can be felt by hand, this almost always indicates a mechanical problem or a violation of the installation rules. Also pay attention to the duration of operation: if the motor hums continuously for hours and does not turn off, the system is wearing out.
There is a simple test to check the noise level. Stand next to the operating unit and listen. If you can calmly talk to the other person without raising your voice, and the sound does not interfere with your concentration, then the technical indicators are probably within the normal range. However, if compressor hum is heard from the next room or it wakes you up at night, intervention is required.
Errors during installation and assembly of equipment
The most common reason why the refrigerator is hummingis its incorrect location in space kitchens. Even a perfectly serviceable motor will create resonance if the unit is not level. Vibration from a running compressor is transmitted to the housing and then to the floor, increasing significantly.
Check the horizontal installation using a building level. The legs of the refrigerator should be adjusted so that the body is slightly set back to allow the doors to fit snugly, but is still stable. If one of the supports does not touch the floor or, on the contrary, is twisted too much, a misalignment occurs, causing vibration.
It is also critically important to maintain the distance to walls and furniture. The operating instructions for any brand, be it Bosch, LG or Atlant, requires a gap for ventilation. If the refrigerator is moved close to the wall or cabinets, vibration is transmitted to them, turning the furniture into a resonator.
☑️ Checking the installation of the refrigerator
External factors: resonance of objects and utensils
Sometimes source The sound does not lie in the motor itself, but in what is inside or outside the chamber. The rattling of dishes, cans or bottles can create the illusion that the compressor is humming louder than usual. When the motor operates, microvibrations occur that are transmitted to the shelves.
Check whether the glass shelves are touching the walls of the chamber. Plastic stops dry out over time, and the glass begins to vibrate against the metal body. This creates an unpleasant ringing noise that can easily be confused with an engine malfunction. It is enough to place a piece of foam rubber between the shelf and the wall or place a rubber mat.
Do not forget about the items standing on the top lid of the refrigerator. Microwave ovens, bread bins or decorative items may resonate with the frequency of the compressor. Remove all foreign objects from the top panel and listen to see if the sound has changed. Often this simple action allows you to eliminate extraneous noise.
Mechanical problems of the compressor itself
If external factors and installation errors are excluded, the problem may lie in the wear of the internal components of the engine. Motor-compressor - this is a complex one a mechanism where pistons move at high speed. Over time, the rubbing parts wear out, backlashes appear, which leads to an increase in noise.
One of the common problems is wear or damage to the motor mount. The compressor inside the casing is mounted on springs or rubber shock absorbers that dampen vibration. If the spring has burst or the rubber has dried out, the motor begins to hit the walls of the casing. This causes a strong metallic clanging and hum.
It is also worth mentioning the problem of “water hammer”. If liquid freon instead of gaseous freon enters the suction system, this causes shock loads on the valves and piston group. In this case refrigerator it may buzz intermittently, with characteristic clicks. This condition is dangerous and can lead to engine wedge.
The following is a table to help classify sounds and their possible causes:
| Sound type | Probable cause | Required actions |
|---|---|---|
| Smooth hum | Normal operation or chassis resonance | Check installation and stability |
| Metal clanging | Failure of the motor mount | Replacing shock absorbers or springs |
| Intermittent beep | Attempt to start in case of malfunction | Diagnostics of the starting relay |
| Whistling or squealing | Lack of oil or bearing wear | Urgent repair or replacement of the compressor |
Malfunctions of the starting relay and electrical equipment
Often the reason What the refrigerator humsbut does not start or starts with difficulty is the starting relay. This small element is responsible for supplying voltage to the motor windings at the moment of start. If the relay contacts are burnt or the mechanism is jammed, the motor cannot gain speed and only hums.
In this mode of operation, the current in the windings increases many times, which leads to rapid heating. The thermal protection relay is activated and the engine is switched off. After some time, the cycle repeats: a click is heard, then a buzz, and then shuts off again. This condition is called “working on a hum” and it is critical for the windings.
⚠️ Attention: If you hear a hum that lasts more than 10-15 seconds without changing to an operating rhythm, and is followed by a shutdown click, immediately turn off the power to the device. Continuing operation in this mode is guaranteed to lead to combustion of the compressor windings.
Replacing the start relay is a simple and inexpensive procedure. However, if after replacing the relay the situation has not changed and compressor continues to buzz without starting, the problem is deeper. Perhaps an interturn short circuit in the windings of the motor itself or a critical voltage drop in the network.
How to check the starting relay yourself?
To check the relay, it must be removed from the compressor. Shake it near your ear: if you hear the ringing of internal parts, it means that the mechanism is damaged and requires replacement. You can also ring the contacts with a tester for the presence of resistance.
Problems with the refrigerant and circulation system
Impaired refrigerant circulation can also affect the acoustic background of the refrigerator. If a blockage has formed in the system (the capillary tube is clogged with oil breakdown products or moisture), the compressor has to work with increased load, trying to push freon. This causes an increased hum.
Another scenario is a freon leak. If there is a lack of refrigerant, the engine runs almost idle or, conversely, tries to compensate for the lack of cold by working non-stop. In both cases, the sound of the engine changes. When there is a leak, a hissing or gurgling sound is often heard, which is accompanied by the hum of the motor.
It is important to note that diagnosing the circulation system requires special equipment (pressure gauges, leak detectors). It is almost impossible to independently determine whether the cause is a hum lack of freon or a blockage without opening the circuit.
⚠️ Attention: Do not try to pierce the tubes yourself or release the remaining freon to check. The refrigerant can be flammable, and moisture entering the system during repairs will damage the compressor in a matter of hours.
When you need to call a specialist
There is a clear line when you should stop home experiments and turn to professionals. If, after checking the stability, absence of resonance of the dishes and visual inspection the noise has not decreased, diagnostics of internal components is required.
An urgent call to the technician is necessary if:
- 🛑 The compressor is humming, but there is no cold is being produced.
- 🛑 The smell of burning or scorched plastic is heard.
- 🛑 The motor heats up to temperatures that are dangerous to touch.
- 🛑 A constant cycle of “starting-humming-shutdown” is observed.
A timely contact with the service center will allow you to replace worn parts, such as shock absorbers or start relay, before the compressor itself fails. Replacing a motor is an expensive procedure, often accounting for up to 70% of the cost of a new refrigerator, so you shouldn’t delay repairs if alarming symptoms appear.
Frequently asked questions (FAQ)
Why does a new refrigerator hum loudly in the first days of operation?
New units may make more noise due to the fact that the parts have not yet gotten used to each other. It is also important to check that all shipping bolts and films have been removed. Usually, after 3-5 days of operation, the noise level decreases to standard.
Can a refrigerator hum due to power surges in the network?
Yes, low voltage in the network does not allow the compressor to develop the necessary power to start. As a result, it buzzes, but does not start. In regions with unstable electricity, it is recommended to use a voltage stabilizer.
Is it dangerous if the refrigerator hums, but continues to freeze?
If the cold persists and the temperature in the chambers is normal, the situation is not critical in the short term. However, an increased hum indicates an increased load on the nodes, which reduces the service life of the equipment. It is recommended to carry out preventive maintenance.
How to reduce noise from an old refrigerator?
Try to install the unit on a thick rubber mat, check the tightness of all visible screws on the back wall and make sure that the condenser (grid at the back) does not vibrate. Sometimes lubrication of the rubbing parts of the engine helps, if there is access, but this requires skills.