A sudden hum or obsessive knocking can ruin atmosphere in any home, turning the kitchen from a cozy place for family dinners into a source of constant irritation. When the refrigerator is noisy, this is not just discomfort, but also a signal that a failure has occurred in the operation of a complex mechanism that requires immediate attention. Ignoring extraneous sounds often leads to more serious damage and expensive repairs.
In this article we will look in detail at why compressor it hums, where the gurgling or crackling comes from, and in what cases the unit works normally. You will learn how to independently carry out initial diagnostics and understand when it is necessary to call a specialist to repair household appliances.
Extraneous sounds can have a different nature: from a trivially unevenly installed housing to failure of expensive components. A sharp change in the characteristic sound of the compressor to a loud knock or metallic clang is a critical signal for immediately disconnecting the device from the network. Let's look at the main reasons in order.
Violation of installation rules and vibration of the housing
The most common and easily eliminated reason is improper installation of refrigeration equipment. If the unit is not level, it compressor begins to vibrate with greater amplitude, transmitting vibrations to the floor and walls. This creates a low-frequency humming effect that intensifies at night.
Check the horizontal installation using a building level. Even a slight misalignment can cause the refrigerator to make loud noise. Adjusting the legs allows you to compensate for uneven floors and reduce vibration levels to a minimum.
- 🔧 Check that all four legs are firmly in contact with the floor surface.
- 📐 Use a level to check the horizontal position of the top cover.
- 🧱 Make sure the back wall does not touch the wall or furniture.
- 🚶 Remove foreign objects that may resonate with vibration.
It is also important to maintain a gap between the back wall of the refrigerator and the wall of the room. The minimum distance should be at least 5-10 centimeters to ensure normal air circulation and absence of resonance.
Faults of the compressor and start relay
If the installation performed correctly, but the refrigerator is noisythe problem may lie in the heart of the unit - the compressor. This is an electric motor that drives the refrigerant through the system. Wear of bearings, imbalance of the rotor or deformation of the motor housing lead to a loud hum that turns into knocking.
Often the source of the noise is starting relaywhich is responsible for starting the engine. If the relay contacts are burnt or the mechanism is stuck, you may hear characteristic clicks before starting or a hum that ends abruptly.
How to distinguish compressor noise from fan noise?
The compressor emits a low-frequency hum and vibration transmitted to the housing. The fan creates high-frequency air noise and can hum when rotating at high speeds, often only audible when the door is open (in No Frost systems).
In some models with two compressors, the noise may come from only one of them. This makes diagnostics easier, since you can localize the source of the sound by placing your hand on different parts of the housing while the motor is running.
- 🔊 A loud metallic knock indicates the destruction of internal components.
- 📉 An intermittent hum with clicks indicates problems with the relay.
- 🔥 Heating The compressor housing is higher than normal - a sign of overload.
- 🔄 Frequent switching on and off indicates control failures.
Diagnostics of the compressor requires certain skills and tools. If you are not confident in your abilities, it is better not to take risks and turn to professionals, since replacing this unit is a labor-intensive process.
Problems with the defrost system and fans (No Frost)
In refrigerators with a No Frost system, fans are responsible for circulating cold air. Over time, ice can build up on the blades, causing imbalance and noise. Also, the fan motor bearings may dry out or wear out, starting to produce an unpleasant grinding noise.
Another reason is ice getting into the rotation zone of the blades. This often happens when the defrosting system malfunctions, when the heating elements do not warm up the evaporator properly, and frozen moisture begins to interfere with the operation of fan.
☑️ Checking the ventilation system
If noise appears immediately after opening doors, this is almost guaranteed to indicate a fan. In most models, it should stop when the door is opened, but if the mechanism is jammed, the sound may persist or change.
⚠️ Attention: Trying to defrost the refrigerator forcibly (with a hairdryer or hot water) may damage plastic parts and electrical components. Use only natural defrosting.
To eliminate the problem, it is often enough to completely defrost the unit within 24 hours. If the noise returns after switching on, the fan will need to be replaced or the defrost system repaired.
Foreign objects and tube resonance
Sometimes the reason is trivial - vibration causes rattling of objects standing next to or inside the refrigerator. Check shelves, bottles and containers. Also, the source of sound can be copper refrigerant tubes, which, when the compressor is operating, begin to vibrate and hit the housing or each other.
Inside the refrigerator compartment, noise can be produced by improperly installed shelves or glass stands. Just adjusting them is enough to eliminate rattling.
- 🥤 Remove glass bottles that may touch each other.
- 🧊 Check the ice tray in the freezer.
- 📦 Make sure food is not touching the back walls.
- 🔩 Inspect the shelf fastenings for play.
From the outside, inspect the radiator grille on the rear wall. If the tubes touch the metal casing, you can carefully (being careful not to damage!) bend them or lay insulating material.
Why does plastic crack?
Sudden changes in temperature cause thermal expansion and contraction of the plastic elements of the inner chamber. This is normal and does not require repair.
Sound diagnostic table
For the convenience of classifying problems, we have compiled a table that helps determine the nature of the malfunction by sound.
| Sound type | Probable cause | Necessity repair |
|---|---|---|
| Monotonous hum | Normal operation of the compressor | No |
| Gurgling, gurgling | Movement of freon in the tubes | No |
| A sharp click and silence | Malfunction of the starting relay | Yes |
| Whistling or squeaking | Bearing wear fan | Yes |
| Loud knocking/metallic clanging | Compressor failure | Yes (urgent) |
Use this table as a primary guide. However, remember that only an experienced technician can make an accurate diagnosis.
The influence of power supply quality and voltage
Unstable voltage in the electrical network is a common cause of noisy operation of the refrigerator. If the voltage drops below the permissible level, electric motor the compressor begins to overload, hum and get very hot.
Modern models have protection installed that turns off the unit during voltage surges, but older models can continue to operate in emergency mode. It is recommended to use a voltage stabilizer or surge protector to protect equipment.
⚠️ Attention: Operating the refrigerator at chronically low voltage in the network can lead to burnout of the compressor windings and a complete replacement of an expensive unit.
Check the outlet into which the device is plugged in. Poor contact in the connector can also cause cracking and sparking, which is accompanied by a characteristic sound.
☑️ Checking the power supply
Natural sounds: when there is no need to worry
Not all sounds indicate a breakdown. Many modern refrigerators make specific noises during normal operation. For example, the sound of flowing refrigerant is often described as gurgling or gurgling.
The cracking sound of plastic when temperature changes is a physical phenomenon of materials expanding. A quiet humming sound is also considered normal when the refrigerator gains temperature after defrosting or loading warm food.
- 💧 Gurgling is the movement of freon through the capillary tube.
- 🌡️ Cracking is the thermal expansion of the plastic of the inner chamber.
- 💨 Hissing - operation of the No Frost system (rarely, but it happens).
- 🔄 Rumble - normal operation of the compressor at high speeds.
If you have recently installed the refrigerator, give it time. In the first days of operation, it may make a little more noise until the temperature conditions stabilize and the moving parts grind in.
Prevention and care of the refrigerator
To extend the life of equipment and avoid the appearance of extraneous noise, it is necessary to regularly carry out preventive maintenance. Cleaning the condenser from dust, checking the seals and timely defrosting will work wonders.
Make sure that the refrigerator is not overloaded with food. This puts extra stress on the compressor, causing it to work harder and noisier.
⚠️ Attention: A condenser clogged with dust (grid at the back) causes the compressor to work harder, which inevitably leads to increased noise and the risk of breakdown. Clean it with a vacuum cleaner every six months.
Regularly check the tightness of the door. If the seal is worn out, the cold goes away, and the refrigerator is forced to turn on more often to maintain the set temperature.
FAQ: Frequently asked questions
Why did the refrigerator start making noise after defrosting?
After defrosting, there could be some water left in the system, which got into the evaporator tray and is now boiling, creating noise. The body could also shift when moved. Let the refrigerator run for several hours, usually the noise subsides.
Is it dangerous if the refrigerator is humming, but is cold?
If the cold persists and the temperature in the chambers is normal, then most likely there is no serious damage. However, an increased hum may indicate wear on the compressor, so it is worth monitoring the situation.
Is it possible to lubricate a compressor if it is noisy?
No, modern compressors are sealed and do not require lubrication during operation. An attempt to drill or open the compressor will lead to its complete malfunction and freon leakage.
Why is an old refrigerator noisier than a new one?
Over time, bearings wear out, fastenings become loose, and play appears in the engine. In addition, older models were structurally noisier due to less effective insulation.
What to do if noise appeared immediately after purchase?
Let the refrigerator sit for 2-4 hours before turning it on (if it was transported lying down). If the noise persists and exceeds the 40 dB stated in the passport, contact the service center under warranty.