The refrigerator is constantly humming - what is the reason and how to fix it

Have you noticed that the refrigerator has become louder than usual? A constant hum that does not stop for hours can be seriously disturbing, especially at night. But this is not always a sign of a breakdown. Modern models (Samsung No Frost, LG Inverter, Indesit and others) really work quieter than old Soviet units, but even they should not be completely silent. In this article we will look at when this is a normal option and when it is a signal of a malfunction. why the refrigerator is constantly humming, when this is a normal option, and when it is a signal of a malfunction.

First, let's define the terms. Humming is a low-frequency sound that is produced by the compressor, fans or circulating refrigerant It can be uniform or pulsating, weak or intrusive. It is important to distinguish it from knocks, creaks or vibrations —these sounds usually indicate other problems. Also pay attention to cyclical operation: if the compressor turns on and off every 10–20 minutes, this is normal; if it works continuously for more than 2-3 hours without pauses, it's time to sound the alarm.

We analyzed data from service centers and user reviews to create a checklist of the most likely causes of the hum. You will learn how to diagnose the problem yourself, when you can get by with adjusting the settings, and when you can’t do without a wizard. We will also look at specific cases for refrigerators with a system No Frost, inverter compressors and models with two motors (for example, ATLANT MXM-2835 or Beko GNE114620X).

1. Normal noise vs. pathological: how distinguish

Before you panic, make sure that your refrigerator really hums too loudEach type of unit has its own “sound portrait”:

• 🔊 Compressor models (for example, Biryusa, Stinol): hum with a slight vibration at startup, then uniform noise ~40–50 dB. Operating cycle: 10–15 minutes working, 5–10 minutes resting.
• 🌀 No Frost (Samsung RB30A3200SA, LG GA-B409SLGL: fan noise is added to the hum of the compressor (~35–45 dB). It may seem that the refrigerator is “howling.”
• ⚡ Inverter (Hitachi R-B320P7MS, Panasonic NR-BN30A1): almost silent (20–30 dB), but at peak loads (for example, after defrosting) they can hum louder.

For an objective assessment, use a sound meter application (for example, Decibel X for iOS/Android). Measure the noise level at a distance of 1 meter from the refrigerator:

If your refrigerator falls into the first two categories, but subjectively seems loud, perhaps the problem is room acoustics. In a small kitchen with tiled floors and bare walls, the sound will resonate more strongly. Try placing soft objects nearby (towels, a rug) - this will help absorb vibrations.

2. Incorrect installation: 5 mistakes that cause the refrigerator to hum

Up to 30% of calls to service centers regarding “breakdowns” are related to incorrect installation. It's easy to check - just inspect the refrigerator and its surroundings. Here are typical mistakes:

• 🪨 Uneven floor: if the refrigerator is tilted, the compressor vibrates more. Use a level or check that the unit does not wobble when lightly pressed.
• 🧲 Contact with furniture/walls: the back wall should be 5–10 cm away from the wall, and the side walls should not touch the cabinets. Otherwise, the vibration increases.
• 🔌 Warped socket: if the plug does not fit into the socket tightly, microvibrations may occur that are transmitted to the body.
• 📦 Transport bolts have not been removed: in new refrigerators (ATLANT, Beko) the compressor is fixed with bolts for transportation. If they are not removed, the motor will hum and knock.
• 🌡️ Near heat sources: a battery, stove or direct sunlight causes the compressor to work non-stop, increasing the noise.

How fix:

Align the legs (adjust the screws at the front)

Move the refrigerator from the wall 5-10 cm

Make sure the plug fits tightly in the socket

Check that the shipping bolts have been removed (instructions in the passport)

Remove heat sources within a radius of 50 cm -->

If after these manipulations the hum does not decrease, proceed to the next sections. Please note: in refrigerators with No Frost (for example, Samsung RB37A5200SA), the fan may make louder noise when the door is open - this is normal. But if the noise does not stop even after closing, perhaps the fan blades are touching the ice or the case (see section 5).

3. Compressor overload: when the refrigerator “does not rest”

The compressor is the “heart” of the refrigerator, and if it works without interruption, the hum will become constant. Normally, the motor should turn on for 10–20 minutes, then turn off for 5–15 minutes. If the cycle is broken, the reasons may be the following:

• ❄️ High temperature in the chamber: for example, after defrosting or if the door has been open for a long time. The compressor will work for wear until it restores mode.
• 🔥 Hot food: did you put a pot of soup in the refrigerator? The motor will have to spend more energy on cooling.
• 📉 Incorrect settings: if you set the temperature to maximum (-24°C in the freezer), the compressor will hum almost constantly.
• 🧊 Ice in the freezer: a layer of ice more than 5 mm thick impairs heat transfer, causing the motor to work longer.

How to check:

1. Open the refrigerator and assess the temperature inside. There should be +2…+5°Cin the main chamber, in the freezer - -18…-20°C.
2. Look for ice on the back wall (in models without No Frost) or on the evaporator (in systems Frost Free).
3. Check whether the shelves are overloaded - air circulation should be free.

Solution:

• Defrost the refrigerator for 10-12 hours (if there is no auto defrost).
• Set the temperature to +4°C in the refrigerator compartment and -18°C in freezer.
• Do not put hot dishes - let them cool to room temperature.

How to quickly defrost a refrigerator without risk to the compressor?

Place containers with hot water (not boiling water!) in the chambers - this will speed up the melting of the ice.

Do not use a hair dryer or sharp objects to chip ice - you can damage the evaporator.

After defrosting, wipe all surfaces dry and let the refrigerator stand for 1-2 hours before turning it on.

If after these steps the compressor still does not turn off for more than 1-2 hours, the problem may be in freon leak or thermostat malfunction (see section 6). In this case, independent repair is dangerous - a specialist with equipment for refrigerant charging is required.

4. Problems with the fan in No Frost systems

Refrigerators with No Frost (Liebherr CNef 4315, Bosch KGE39AW25R) are equipped with a fan that distributes cold air among the chambers. If it starts to hum louder than usual or makes noise grinding/whistle, the reasons may be:

• ❄️ Ice on the blades: if the defrosting system malfunctions, ice builds up on the fan, and it touches it when rotating.
• 🔧 Unbalanced blades: if one of the blades is bent or cracked, the fan vibrates and hums.
• 🐭 Foreign objects: crumbs, pieces of packaging or even insects can get into the mechanism.
• 🔌 Bearing wear: over time, the lubricant dries out and the fan begins to “howl.”

Diagnostics:

1. Disconnect the refrigerator from the power supply.
2. Remove all food from the freezer and remove the back panel (in most models it is secured with latches or screws).
3. Check the fan blades for ice or damage. In models Samsung i LG the fan is usually located behind a plastic cover at the top of the freezer.
4. Turn the blades by hand - they should rotate easily, without snagging.

Solution:

• If there is ice, defrost the refrigerator and check the operation of the defrosting system (heating element and timer).
• If the blades are damaged, replace the fan (the part can be ordered by model code, for example, DA97-08007A for Samsung).
• If the bearing is worn, the entire motor will need to be replaced fan.

⚠️ Attention: If you can hear the fan when operating clicking or crackling, immediately turn off the refrigerator This may indicate! jamming of the motor, which will lead to a fire.

5. Compressor malfunctions: when repairs are required

If the refrigerator is humming continuously for more than 3-4 hours, and all previous checks did not produce results, the problem may lie in the compressor itself. Here are typical malfunctions:

• 🔋 Motor wear: over time, the piston rings and valves of the compressor wear out, and it begins to hum louder, losing performance.
• 💨 Freon leak: if the refrigerant has leaked, the compressor runs “idle”, trying to create pressure, but cannot cool the chambers.
• 🔌 Interturn short circuit: the motor windings are damaged, which leads to overheating and increased noise.
• 🛠️ Faulty start relay: if the relay “sticks”, the compressor does not turn off, which leads to overheating and humming.

Signs that the culprit is compressor:

• The refrigerator does not cool, but hums.
• The compressor housing (black “barrel” at the back) is hot to the touch.
• Audible metallic knocks inside the motor.
• There is no condensation on the back wall of the refrigerator (a sign of lack of freon circulation).

What to do:

1. Turn off the refrigerator and let it cool for 1-2 hours.
2. Check temperature in the chambers. If, after turning on, the refrigerator does not cool and the compressor hums, this is a sign of a freon leak or a motor failure.
3. Call the service center. Repairing the compressor or refilling freon requires special equipment and certified technicians.

⚠️ Attention: If the compressor is it smokes or smells like burning, immediately unplug the refrigerator and do not turn it on until the technician arrives! These are signs of a short circuit that can lead to a fire.

6. Other causes of hum: from the condenser to electronics

Sometimes the hum does not come from the compressor or fan, but from other components of the refrigerator. Let's consider less obvious reasons:

• 🔄 Capacitor (grill at the back): If it is dirty with dust or deformed, it may vibrate and hum. Clean it with a soft brush.
• 📶 Electronic control unit: in modern models (Samsung Family Hub, LG ThinQ), firmware failures can lead to continuous operation. compressor.
• 🔗 Refrigerant pipes: if they rub against the housing or against each other, a low-frequency hum occurs. Gently bend them (do not pinch!).
• 🔋 Inverter unit (in models with inverter compressor): during voltage surges, it can emit a high-frequency squeak.

How to diagnose:

1. Turn off the refrigerator and listen - if the hum disappears, the problem is in the electronics.
2. Check the voltage in socket (should be 220–230 V). If it jumps, use a stabilizer.
3. Inspect the capacitor for dents or dirt.

Solution:

• To clean the condenser, use a vacuum cleaner with a narrow nozzle or a brush. Do not use water!
• If you suspect an electronics failure, try resetting the settings to factory settings (instructions in the passport, usually "Power" + "Temp" button for 5 seconds).
• If you suspect a malfunction of the inverter or control unit, contact the service.

How to reset the Samsung No Frost refrigerator?

1. Disconnect the refrigerator from the power supply for 1 minute.

2 Turn on and immediately press simultaneously Fridge (Refrigerator) and Freezer (Freezer) for 8-10 seconds.

3. Wait for the sound signal - the settings will be reset.

⚠️ Attention: If after resetting the settings the refrigerator starts the indicators beep or flash, this may indicate critical error. In this case, do not try to reflash the unit yourself - contact a specialist.

7. When to call a technician: a checklist for making a decision

If you have checked all possible reasons, but the refrigerator is still humming, it’s time to contact service. Here are the signs that you can’t do without professional help:

The refrigerator is not cooling, but the motor is humming

The compressor is hot and does not turn off for more than 4 hours

You can hear metallic knocking or grinding noises

There is no condensation on the back wall (a sign of freon leakage)

The electronic panel shows an error (for example, E1, F2)-->

The cost of repairs depends on the model and type of malfunction. For example:

• Replacing the thermostat in Indesit or ATLANT will cost 1 500–2 500 ₽.
• Repair of inverter compressor in LG or Samsung - from 10 000 ₽.
• Refilling freon in Beko or Bosch — 3 000–5 000 ₽.

Where to look for a specialist:

• Official service centers of the brand (repair warranty up to 1 year).
• Verified private workshops (read reviews on Yandex.Maps or 2GIS).
• Home repair services ("RemBytTekhnika", "Cold Service").

Before the technician’s visit:

1. Defrost the refrigerator (if it is not cooling).
2. Prepare a product passport (the model and serial number are indicated there).
3. Take a photo or record a video of “symptoms” (this will help the technician diagnose faster problem).

Frequently asked questions about the hum of the refrigerator

❓ Why does the new refrigerator hum louder than the old one?

Modern models (No Frost, inverter) may seem louder due to the fans and higher compressor speed. However, their actual noise level is usually lower (30–45 dB versus 50–60 dB for older refrigerators). Getting used to it takes 1–2 weeks. If the noise does not decrease, check the installation and settings.

❓ Is it possible to charge freon yourself?

No. Refrigerant charging requires special equipment (vacuum pump, pressure gauges) and certification. Improper refueling may lead to compressor explosion or leakage of toxic substances. Contact only licensed services.

❓ Why does the refrigerator hum at night, but is quieter during the day?

At night the house is quieter, and the noise of the refrigerator seems louder. There are also two possible technical reasons:

1. At night, the temperature in the kitchen drops, and the compressor turns on more often to maintain the mode.
2. If the refrigerator is located next to the radiator, during the day the heating from the heating compensates for the operation of the motor, and at night (when the heating is weaker) the compressor works more intensely.

Solution: adjust the legs of the refrigerator for better shock absorption or move it away from the battery.

❓ How long can the compressor work without stopping?

Normally, the compressor operates in cycles:

• Summer/heat: up to 20–25 minutes work and 5–10 minutes rest.
• Winter/cold: before 10–15 minutes work and 15–20 minutes rest.

If the compressor works more than 1-2 hours without pauses, this is a sign of a malfunction (freon leakage, thermostat failure and etc.).

❓ Why does the refrigerator hum and heat up on the sides?

The side walls of the refrigerator can heat up to 30–40°C - this is normal, since the condenser tubes pass through them. The hum is usually associated with:

• Intense operation of the compressor (for example, after defrosting).
• Condenser contamination (dust impairs heat transfer, and the motor wears out).

Clean the rear grille and check whether the refrigerator is standing close to the wall (there should be a gap 5–10 cm).