Owners of modern household appliances are often faced with a situation when LG refrigerator begins to make unusually loud sounds. Noise can manifest itself in the form of buzzing, crackling, gurgling or high-pitched whistling, which creates noticeable discomfort, especially in small apartments or studios. The system No Frost, which is designed to save the user from manual defrosting, has a more complex design than drip counterparts, and includes additional components capable of generating acoustic vibrations.
Understanding the nature of sound is the first and most important step to solving the problem. Inverter compressor, often installed in units of the Korean brand, works on the principle of changing the engine speed, which in normal mode ensures silence, but in case of malfunctions it can produce a low-frequency hum. It is important to learn to distinguish between the normal functioning of equipment and signs of impending breakdown, so as not to miss the moment when specialist intervention becomes critically necessary.
In this article we will analyze in detail the mechanical and electrical causes of noise, consider the influence of operating conditions and propose an algorithm of actions for self-diagnosis. A sharp change in the nature of the sound in the first 2-3 minutes after starting the compressor often indicates mechanical wear of the internal parts of the motor. Correct interpretation sound signals will help you save time and money by preventing more serious breakdowns.
Physical causes of noise in No Frost systems
The main source of sound waves in any refrigeration unit is vibration. In systems No Frost air circulation is forced, which requires fans. When you hear a hum, it is most often the result of resonance between the vibration of the operating parts and the structural elements of the housing or interior of the camera. Metal tubes, plastic partitions and even shelves can resonate, amplifying the original sound many times over.
Another factor is the operation of the refrigerant. As freon passes through the capillary tube and expansion valve, a sharp change in pressure occurs, which may be accompanied by a characteristic gurgling or hissing sound. If the refrigerator is not installed correctly, these sounds can be transmitted to the floor or walls, creating the effect of a "humming" room. Vibration is the key word to keep in mind when looking for the source of the problem.
⚠️ Attention: If the humming is accompanied by strong vibration of the floor under the legs of the refrigerator, this may cause to the gradual destruction of the soldering of the copper evaporator tubes. Do not ignore strong mechanical vibrations of the housing.
It is also worth considering the thermal expansion of materials. The plastic of the inner box and metal elements change their geometric dimensions when cooled and heated, which sometimes leads to cracking or clicking sounds. However, if the sound is a constant monotonous hum, we are talking about a continuous process, and not about one-time thermal deformations.
Diagnostics of compressor and start relay faults
The heart of any refrigerator is the compressor. LG models often use modern inverter motors, which are considered to be among the quietest on the market. However, if you hear increasing humwhich does not stop after the temperature rises, the problem may lie in this particular node. Wear of the shaft bearings or imbalance of the rotor leads to beating, which is transmitted to the housing and amplified by resonance.
In older models or units with classic starting, the cause may be a faulty starting relay. If the contacts stick or the winding hums, but startup does not occur, you will hear a characteristic low-frequency hum followed by a click. This is a dangerous operating mode, as the engine can burn out from overheating. Inverter systems do not have a starting relay in the classical sense, but the control module (inverter board) can also emit a high-frequency squeak or hum when the capacitors are faulty.
How to distinguish an inverter compressor?
An inverter compressor operates continuously, changing power, so it should not suddenly turn on and off with a loud click. If your LG operates cyclically (on-off) and at the same time makes a strong hum, the inverter board may have failed and the motor is operating in emergency mode of a conventional compressor.
To check the condition of the compressor, you can use the following method: carefully place your palm on the side wall of the unit in the area of the motor. If the vibration is transmitted to the hand very strongly and is felt as “blows”, this indicates mechanical wear of the internal components. In such cases, it is required replacement of the compressor, since repairing the old one is often not economically feasible.
Problems with evaporator and condenser fans
The system No Frost cannot function without fans. There are usually two of them in an LG refrigerator: one blows cold air into the chamber (located behind the back wall of the freezer), the second cools the condenser (located at the bottom back). If you hear a humming sound that turns into a howl or whistle, there is a 90% chance that the source is the fan.
The main causes of fan noise:
- 🧊 Ice on the blades blades: If the defrost system does not work correctly, ice can build up on the blades, disturbing the balance and creating a hum when rotating.
- 🌀 Wear of the bearings: Over time, the lubricant in the bearings of the fan motor dries out, and it begins to hum or creak.
- 📏 Touching the blades: Vibration or displacement of the mount can lead to the blades touching the walls of the box or ice.
To check the evaporator fan, you need to defrost the refrigerator (completely, at least 10-12 hours) and start it without food. If after defrosting the noise disappears for several days and then appears again, there is a problem in the defrosting system (heating element, sensor or timer). If the sound remains immediately after turning on, most likely the fan itself needs to be replaced.
☑️ Checking the fan
The influence of incorrect installation and resonance
Often the reason that the LG refrigerator makes a loud noise is not a breakdown, but a banal violation of the installation rules. The unit must stand strictly horizontally and vertically. If the legs are not twisted correctly, the body warps, which leads to a loose fit of the internal elements and the appearance of resonance zones.
Check the distance to the walls and furniture. For normal air circulation and noise reduction, it is necessary to observe the gaps specified in the instructions (usually at least 5-10 cm). If the refrigerator is close to a wall or furniture, the sound from the running motor is reflected and amplified. Also, vibration can be transmitted to the floor if it is not strong enough or has voids.
| Installation parameter | Standard value | Consequences of violation |
|---|---|---|
| Gap at the back | Minimum 5-10 cm | Compressor overheating, increased noise |
| Gap on the sides | Minimum 5 cm | Wall resonance, difficult access |
| Position legs | Level adjustment | Vibration of the body, noise when opening doors |
| Remote from the stove | Minimum 30 cm | Overheating, increased wear seal |
Try to slightly tilt the refrigerator body forward or backward without lifting the legs from the floor. If the hum pattern changes, then you have found a resonant point. In this case, adjusting the height of the legs or placing anti-vibration pads made of thick rubber under them will help.
Foreign objects and the condition of the internal shelves
Do not discount the internal contents of the refrigerator. Glass shelves that are not fully installed in the grooves or plastic trays may vibrate due to the operation of the compressor. The sound, which seems to be the hum of the unit itself, may in fact be the rattling of a bottle or container.
Carry out a simple test: one by one, remove all the shelves and drawers from a working refrigerator. If the noise disappears after removing a particular shelf, the problem has been found. The solution may be to place a piece of foam rubber or a special silicone mat under the shelf. Also check that the food does not touch the back wall of the chamber where the evaporator is located.
Pay special attention to the freezer area. Ice build-up on the bottom of the freezer can touch the fan blades, creating a cracking and humming noise. Regular defrosting (every 6-8 months) will help avoid the formation of excess ice, even in systems No Frost.
⚠️ Attention: Do not use sharp objects to chip ice inside the freezer. Damage to the evaporator will lead to a freon leak and expensive repairs, which can cost up to 70% of the price of a new refrigerator.
When you need to call a technician: critical signs
There are a number of symptoms in which independent repair attempts can be not only useless, but also dangerous. If the hum is accompanied by a burning smell, melted wiring or sparking, immediately unplug the device. These are signs of an electrical malfunction that requires professional diagnostics.
It is also worth contacting a service center if:
- 🔥 Compressor hot: If the motor-compressor is hot to such an extent that it is impossible to touch it, this indicates an overload or an interturn short circuit.
- 💧 The appearance of oil: Notice oily stains under the refrigerator or on the pipes? This is a sign of depressurization of the system.
- 📉 Lack of cold: If the refrigerator hums constantly without turning off, but the temperature in the chambers does not drop, it means that the cooling cycle is broken (freon leak, capillary blockage).
Modern LG refrigerators are equipped with a self-diagnosis system. Pay attention to the indicators on the control panel. The blinking of certain lights may indicate a specific error, which the technician considers using special equipment.
Noise prevention and service life extension
To make your LG No Frost refrigerator happy with silence for as long as possible, it is important to follow the operating rules. Do not load the chambers with hot food - this forces the compressor to work at its limit, increasing noise levels and wear. Keep the condenser (grid at the back) clean, as a layer of dust 1 mm thick can increase the operating temperature of the motor by several degrees.
Regularly check the integrity of the rubber seals on the doors. If the rubber becomes dry or dirty, warm air enters the chamber, and the refrigerator is forced to hum more often and longer, compensating for heat loss. Wipe the seal with a soft cloth and soapy water once a month.
Timely maintenance is the key to silence. Even if the refrigerator is working properly, a preventive inspection by a specialist once every 2-3 years will help identify incipient problems with fans or seals before they become a source of constant noise.
Why does the refrigerator hum only at night?
At night, the overall noise level in the apartment decreases, and the sounds of equipment operation become more noticeable. In addition, the power supply voltage may drop at night, causing the compressor to work harder and produce a lower-frequency hum. Also at night it is often quieter in the ventilation shafts, which improves audibility.
Is it possible to lubricate the fan yourself?
Theoretically, it is possible if you remove the fan and drop oil into the bearing. However, in modern LG models, fans are often assembled and do not require maintenance. In addition, poor-quality lubricant can freeze at low temperatures, which will lead to jamming. It is safer to replace the entire assembly.
Does the number of products affect the noise level?
Yes, it does. An empty refrigerator is noisier because there is nowhere for the food to cool, and the air temperature fluctuates faster, causing the compressor to turn on more often. A completely clogged refrigerator can also create air circulation problems, increasing the load on the fan. The optimal load is 60-70%.
What to do if a new refrigerator is humming?
A new refrigerator may hum more strongly in the first days of operation due to grinding in of parts. Let it sit off for a few hours after delivery, then turn it back on with no load. If after 3-5 days the loud hum does not subside, contact the store for a replacement or warranty repair.