Suddenly appearing Extraneous sounds from household appliances always cause alarm. When the refrigerator clicks, owners often panic, expecting expensive repairs or complete breakdown of the unit. However, a characteristic knock or crackling sound does not always indicate a critical malfunction that requires calling a technician.
Modern refrigeration units are complex engineering systems, where many parts are in constant motion or under the influence of temperature changes. Understanding the physics of processes helps to distinguish normal operation of equipment from a real breakdown. In this article, we will analyze in detail all the possible causes of clicking.
You will learn how to carry out initial diagnostics yourself, so as not to overpay for the services of a service center in cases where the problem can be solved yourself. It is important to listen carefully to the nature of the sound and determine its localization.
Natural physical processes and thermal expansion
The most common and absolutely safe reason for something clicking in the refrigerator is the thermal expansion of materials. The inner walls of the chamber, plastic shelves and metal elements of the evaporator are made of substances with different expansion coefficients. When there is a sudden change in temperature, for example, immediately after turning on the compressor or the end of the cycle defrosting, materials compress or expand.
This process is often accompanied by sounds reminiscent of cracking plastic or short clicks. This phenomenon is especially often observed in models with a No Frostsystem, where temperature changes are more intense due to constant air circulation. Sounds can occur both during cooling and when heating elements during defrosting.
Usually such clicks do not pose any threat to the performance of the unit. They may be repeated periodically throughout the life of the device. If the sound occurs precisely at the moment of changing operating modes, there is nothing to worry about.
⚠️ Attention: If the crackling becomes very loud, like gunshots, or is accompanied by a burning smell, immediately unplug the device. This may indicate overheating of the wiring or melting of plastic parts.
Operation of the starting relay and electrical circuit
One of the technical reasons for the sound of the refrigerator is the functioning of the start relay. This small but important element is responsible for starting the engine compressor. When the engine is turned on, the relay makes a characteristic loud click, closing the circuit. A similar, but sometimes quieter sound can be heard when the unit is turned off, when the circuit opens.
If the click is heard once when starting and once when stopping, this is a normal situation. However, if you hear a series of rapid clicks, after which the refrigerator hums for a few seconds and turns off again, this is an alarming symptom. This situation often indicates a malfunction of the relay itself or problems with the compressor windings.
In older models, relays can be electromagnetic, in new ones they can be thermal or electronic. The sound may vary slightly. A loud, metallic clang when trying to start, which is repeated cyclically, requires the intervention of a specialist.
How to check the relay yourself?
To check, you need to remove the back cover of the refrigerator, disconnect the relay from the compressor and shake it. If a ringing or knocking sound of the ball is heard inside, then the mechanical part is damaged and the relay must be replaced.
Problems with the compressor and motor
The compressor is the heart of the refrigeration system, and any changes in its sound profile require attention. Sometimes users hear not just a click, but a dull knock or clanging sound coming from the motor. This may indicate that the compressor is working under increased load or has mechanical damage to internal components.
It is important to distinguish between the sounds of a running motor and extraneous noise. Normal operation accompanied by a steady hum. If rhythmic tapping is added to the hum, it is possible that the internal springs on which the motor-compressor is suspended have shifted. During operation, they may touch the housing, producing a metallic sound.
The knocking can also be caused by water hammer if oil or liquid phase refrigerant has entered the system, although this is more typical for industrial installations. In domestic conditions, wear of bearings or valves is more common, which leads to increased noise over time.
Failures in the defrosting system (No Frost)
Refrigerators equipped with the system No Frosthave an automatic defrost cycle. This process involves a heating element (heating element), a timer and a fan. Clicking noises in such models may be associated with the operation of the evaporator fan. If ice builds up on the blades, the fan may touch the ice, producing a cracking sound or a series of clicks.
Another source of sound is the defrost timer. Mechanical timers make a distinct click when switching modes (cooling/defrosting). This happens approximately every 8-12 hours of operation. If the sound is heard exactly with such frequency and lasts a fraction of a second, this is the normal operation of the automation.
However, if the defrosting system does not work correctly, for example, the heating element heats up too sharply, rapid expansion of the metal may occur, which causes louder sounds. It is also worth checking whether the fan blade is touching wires or fasteners.
☑️ Diagnostics of the No Frost system
Improper installation and vibration of the case
Often the cause of banal clicks and knocks lies in the incorrect installation of the refrigerator. If the device is not level, vibration from the operating compressor is transmitted to the housing and intensified. As a result, plastic trim elements, shelves or bottles on the door may touch and make sounds at the slightest vibration.
Check the stability of the unit. It should not wobble when lightly pressing on the corners. Height adjustment is carried out using the front support legs. It is also important to provide a gap between the back wall of the refrigerator and the wall of the room to avoid resonance.
Sometimes the door itself makes clicks if the magnetic seal or hinges are warped. When closing or opening, as well as when popping from the wind or draft, sounds may occur.
Comparative table of causes of noise
For ease of diagnosis, we We systematized the main causes of clicking in a table. This will help you quickly navigate the nature of the malfunction.
| Cause | Sound character | Frequency of occurrence | Need for repair |
|---|---|---|---|
| Thermal expansion | Crackling, short clicks | When turning on/off | Not required |
| Start relay | Loud metallic click | When starting motor | With frequent repetitions |
| Fan No Frost | Rhythmic crackling, knocking | Constantly or cyclically | Requires cleaning or replacement |
| Vibration of the housing | Rattling, knocking of objects | When the compressor is running | Adjusting the legs |
| Wear of the compressor | Thud knocking, clanging | Constantly during operation | Unit replacement required |
Analysis of data in the table allows you to weed out false alarms. If your case matches the first or last row of the table (in terms of vibration), you can easily handle it yourself. In other cases, more in-depth diagnostics may be required.
Please note that for different brands, such as Indesit, Atlant or LG, the nature of the noise may differ slightly due to the design features of the compressors and housing materials.
When you need to call a technician
There are a number of signs that cannot be ignored. If clicks are accompanied by the fact that the refrigerator has stopped freezing and food has begun to spoil, this is a clear signal of a serious breakdown. You should also be wary if the compressor tries to start, clicks, hums for a couple of seconds and stalls again.
Repeated on-off cycles with a characteristic click of the relay indicate that the protective device is triggered due to overload. Operating equipment in this mode can lead to burnout of the motor windings, which will significantly increase the cost of repairs.
If you notice that the rear grille (condenser) heats up unevenly or, conversely, remains cold when the engine is running, this indicates problems with the refrigerant or compression. In such cases, independent repair is not recommended.
⚠️ Attention: Do not try to open the sealed circuit or change the refrigerant yourself. This requires special equipment, license and skills. Unprofessional intervention can lead to permanent failure of the equipment.
Is it possible to use a refrigerator with a clicking relay?
Short-term - yes, but it is risky. The compressor may burn out due to overheating due to frequent starts. It’s better to wait for the technician.