Extraneous sounds, sounds coming from operating household appliances always cause alarm to the owner. Especially when it comes to refrigerator, which is one of the most important and energy-intensive appliances in the kitchen. When you hear the refrigerator clicking from behind, your first reaction is to try to understand whether this is normal or a harbinger of a serious breakdown. In most cases, periodic clicks are the normal operation of the system, but there are exceptions that require intervention.
The nature of the sound can be different: from a quiet, barely audible crackling to loud, sharp blows, reminiscent of gunshots. It is important not to panic in advance, but to listen carefully to the rhythm and frequency of repetition. If the sound occurs cyclically along with the engine starting or stopping, this is one scenario. If the clicks are chaotic or accompanied by other symptoms, such as lack of cold or overheating of the case, the situation requires a more in-depth analysis.
In this article we will analyze in detail the physical and technical causes of noise. You will learn which parts make sounds during normal operation, and how to diagnose a malfunction without calling a technician. Understanding the structure of your unit will help save time and money, as well as extend the life of the equipment. compressor or relay without calling a specialist. Understanding the design of your unit will help you save time and money, as well as extend the life of your equipment.
Natural sounds of a working refrigerator
Modern refrigerators, whether Indesit, Atlant or premium LG, are complex thermodynamic systems. During their operation, many physical processes occur that cannot take place absolutely silently. Most often, clicks at the back, especially at the bottom of the case, are associated with thermal expansion of materials. The plastic of the inner box, metal tubes of the evaporator and condenser constantly change their temperature.
When the compressor turns off after the cooling cycle, the temperature in the chamber begins to rise, and the tubes begin to heat up. When heated, the metal expands, which is accompanied by a characteristic crackling or clicking sound. This is an absolutely normal phenomenon, known as thermal deformation. This is especially common in new models or after intensive defrosting. If the clicks are rare and are not accompanied by malfunctions, there is nothing to worry about.
Another source of natural noise is the movement of the refrigerant. Freon circulating through the system may make gurgling sounds, which are sometimes perceived as light knocks or clicks when passing through narrow sections of the capillary tube. It is also worth considering the operation of the system No Frostif it is provided in your model. Fans and dampers that regulate air flow can make mechanical sounds when switching modes.
- 🔊 Thermal expansion of plastic and metal when temperature changes.
- 💨 Movement of refrigerant through the system pipelines.
- ❄️ Operation of fans and dampers in No Frost systems.
It is important to note that manufacturers of household appliances take these acoustic effects into account when designing. However, noise levels may vary depending on the quality of materials and workmanship. Cheaper models may click louder due to the use of thinner plastic, which reacts more quickly to temperature changes. If your refrigerator operates reliably and keeps food fresh, most likely these sounds are simply the “voice” of working physics.
Start and protection relays: the main source of clicking
While natural sounds can be ignored, then clicks associated with the electrical part require attention. The main “conductor” of the motor’s operation is start relay. It is this small component that is responsible for supplying voltage to the motor windings at startup. When you hear a loud, audible click at the bottom rear of the refrigerator, 80% of the time the source of the sound is located here.
The principle of operation of the relay is simple: when power is applied, current passes through the start winding, creating a magnetic field that draws in the core and closes the contacts. This process is accompanied by sound. After the engine has picked up speed, the relay opens the starting winding circuit, which is also accompanied by a click. Thus, each cycle of turning the compressor on and off is accompanied by a pair of characteristic sounds. This is a normal situation for most models, including old Soviet ZIL and modern Bosch.
However, if the clicks become too frequent, or you hear a series of quick clicks before the engine hums and goes silent, this is a sign of a malfunction. Perhaps the relay is worn out, the contacts are burnt, or a breakdown has occurred. In such cases, the engine tries to start, but the relay immediately opens the circuit, protecting the windings from overload. This phenomenon is often called a “base” or “chirp.”
How to check the relay yourself?
To check, you need to unplug the refrigerator, remove the back cover and carefully remove the relay from the compressor. Shake it: if a ringing or knocking sound is heard inside, it means that the mechanical part is destroyed and the part requires replacement. Visually inspect the contacts for carbon deposits.
Replacing the start relay is one of the simplest and most accessible procedures in repairing refrigerators. The part is inexpensive and often does not require a special tool for dismantling, other than a screwdriver. The main thing is to choose an analogue with exactly the same characteristics, since the starting current parameters for different compressor models may differ. If you are not confident in your abilities, it is better to entrust this operation to a professional so as not to damage the expensive compressor.
Compressor: when the motor requires attention
The heart of the refrigerator is compressor. It is this that creates the pressure necessary for the circulation of freon. When in good condition, a modern inverter or linear compressor operates almost silently, producing only a low hum. However, if you hear loud metallic clangs, knocks or a series of clicks coming directly from the motor housing, this is an alarming signal.
One of the reasons may be wear of the internal mechanical parts: the piston group, valves or bearings. When the gaps between parts increase, knocking noise occurs. In some cases, clicking noises may be caused by the compressor being stuck or seized. When trying to start, the electric motor hums, the relay clicks, trying to start it, but the shaft does not turn. After a few seconds, the thermal protection is triggered, and everything calms down until the next cycle.
It is also worth paying attention to the fasteners. The compressor is mounted on shock-absorbing suspensions (rubber feet or springs) that dampen vibration. Over time, the rubber dries out and the bolts can become loose. As a result, during operation, the motor begins to vibrate and hit the metal housing or tubes, creating a rhythmic knocking noise that can easily be confused with internal failure. Tightening the mounts or replacing shock absorbers often solves the problem.
⚠️ Attention! If the compressor makes a loud metallic noise and the motor housing becomes red hot or reaches temperatures that are dangerous to touch, immediately unplug the refrigerator. Operation in this mode can lead to fire or complete failure of the unit.
Diagnostics of a compressor requires special skills and equipment, such as pressure gauges for measuring pressure in the system. It is not recommended to climb inside the sealed circuit on your own. If you suspect a fault in the “heart” of the refrigerator, it is better to call a technician to measure the current consumption and discharge pressure. These parameters will definitely tell you about the health of the motor.
The influence of the No Frost system and defrosting
Owners of refrigerators with the system No Frost often encounter special sounds that are not present in models with a drip defrosting system. In such units, the evaporator defrost process is automated and occurs on a timer. At this moment, clicks may occur associated with the operation of additional components.
First, this is the defrost heating element. When it is turned on and off, as well as during heating and cooling, microdeformations may occur, accompanied by sounds. Secondly, the No Frost system uses a special valve that shuts off the freon supply during defrosting. The activation of the solenoid of this valve is often accompanied by a distinct click that can be heard throughout the kitchen.
In addition, a fan is installed in the freezer compartment of such refrigerators. If ice builds up on the fan blades or dust gets into the fan bearing, it may start making cracking or clicking noises. Sometimes the blades can touch ice on the walls of the chamber, which also creates a rhythmic noise that intensifies when the door is opened (since in many models the fan stops when the door is opened).
It is also worth mentioning the defrost sensors. They control the temperature of the evaporator and give a command to turn the heating element on or off. Switching of these sensors may also be accompanied by a quiet click. If the defrosting system does not work correctly (for example, the heating element does not turn off on time), this can lead to the formation of ice jams and the appearance of new, louder sounds when the fan operates.
Diagnostics: normal or broken?
To understand whether you need to call a repair service, you should carry out an initial diagnosis. It will help to separate the “symptoms” of normal operation from the signs of a real disease of the unit. Below is a table that will help classify the sounds heard and determine the degree of danger.
| Sound type | Frequency | Associated signs | Probable cause |
|---|---|---|---|
| Quiet crackling | Periodically | No | Thermal expansion (Normal) |
| Loud click | When turning on/off | The light comes on, it's cold | Relay operation (Normal) |
| Series of clicks | Frequent, before stopping | The refrigerator does not freeze | Relay or starter malfunction |
| Metal clanging | Constantly during operation | Vibration, motor heating | Compressor wear |
Pay attention to the work cycle. If the refrigerator clicks, but the desired temperature is maintained inside, the food does not spoil, and there is no excess ice on the walls, most likely there is no critical failure. You should sound the alarm if the clicking sounds are accompanied by a lack of cold. This indicates that the compressor is humming, the relay is clicking, but does not start, or the freon is not circulating.
Odor is also an important diagnostic sign. If the clicks are accompanied by the smell of burnt plastic or burning, this indicates overheating of the wiring, melting of the insulation or combustion of the motor winding. In this case, operation of the device is prohibited until the malfunction is eliminated.
Prevention and care of the rear panel
To minimize the risk of extraneous noise and extend the life of the refrigerator, it is necessary to regularly care for its technical part. The back panel, where the condenser (grill) and compressor are located, often becomes a place for dust and pet hair to accumulate. This leads to a deterioration in heat transfer.
When the condenser is clogged with dust, the compressor has to work longer and harder to reach the set temperature. This leads to more frequent switching and, accordingly, more frequent relay clicks. In addition, overheating reduces the life of the motor. Regular cleaning of the back with a vacuum cleaner or dry brush is a simple but effective preventive measure.
☑️ Annual refrigerator maintenance
It is also important to ensure correct installation of the unit. The refrigerator should stand level, without distortions. If the feet are not adjusted correctly, the housing may become warped, placing unnecessary stress on the compressor tubes and mounts, causing additional vibration noise. Use a building level to check.
⚠️ Attention! Before any cleaning of the rear panel or checking the fastenings, be sure to unplug the refrigerator from the electrical outlet. Working with live electrical appliances is life-threatening, and moisture getting on the contacts can cause a short circuit.
Don’t forget about placement. If the refrigerator is placed close to a wall or furniture, vibration from the compressor can be transmitted to adjacent surfaces, increasing the resonance and creating the illusion of louder noise. Leave a small gap (at least 5-10 cm) for free air circulation and vibration damping.
Frequently asked questions (FAQ)
Why does the refrigerator click but does not turn on?
Most likely, the starting relay or starter has failed capacitor The engine tries to start, a click is heard, but the protection is triggered and it stalls. There may also be a malfunction of the compressor itself (an interturn short circuit or a wedge).
Is it normal for a new refrigerator to click loudly?
In the first days of operation, sounds may be more noticeable due to grinding in of parts and active thermal expansion of new materials. If the clicks are rhythmic and correspond to switching cycles, this is normal.
Can I continue to use the refrigerator if it clicks?
If the cold remains and there is no burning smell, you can use it until the technician arrives. However, if the clicks are very frequent (every few seconds) and the motor does not start fully, it is better to turn off the device so as not to burn the windings.
How much does it cost to replace a relay in a refrigerator?
The relay itself is inexpensive (usually in the range of 500-1500 rubles depending on the model), but to this amount you need to add the cost of the work of a repairman I'll call. Replacement takes about 15-20 minutes.
Does the voltage drop affect the clicking sound?
Yes, when the network voltage is low, the compressor may not have enough power to start. The relay will constantly click, trying to start the engine, but it will only hum. In such cases, it is recommended to use a voltage stabilizer.