The situation when an extraneous sound is heard behind the refrigerator often takes owners by surprise. It becomes especially alarming if this sound resembles a click, knocking or intermittent crackling. In most cases, it is too early to panic, since modern climate control technology has a complex design, where many parts are in motion or under the influence of temperature changes. However, you should not ignore obvious changes in the acoustic background either, because extraneous noise may signal an incipient malfunction or incorrect installation of the unit.
The first thing you need to do when you hear strange sounds is to try to localize the source. The sound can come directly from the compressor motor, from the refrigerant circulation system, or even from vibration of the housing against furniture. Understanding the nature of sound will allow you to make the right decision: call a technician for refrigerator repair or simply correct the position of the equipment in the kitchen. Let's look at the main reasons why there is a click behind the refrigerator and determine in which cases it is normal.
It is important to immediately note that the nature of the sound plays a key role. A dull knock, a loud click or periodic clicking - all these nuances indicate different processes inside the unit. Inverter compressor, for example, works differently than a classic linear one, and their sound background will be different. In this article we will look in detail at the mechanical, thermal and electrical causes of clicking.
⚠️ Attention: If clicking is accompanied by a burning smell, sparking or a complete blackout of light in the apartment, immediately turn off the power to the device and call a specialist. This may indicate a short circuit in the electrical circuit.
Thermal expansion and contraction of materials
The most common and absolutely safe reason for a click behind the refrigerator is related to the physics of materials. The internal walls of the chamber, the evaporator and the cooling system pipelines are made of plastic and metal. During operation, the temperature of these elements constantly changes: either decreasing during active cooling, or increasing during periods of inactivity. When heated, materials expand, and when cooled, they contract, which causes characteristic clicks, crackling sounds, or even loud bangs.
Such sounds can be heard especially often in new models of refrigerators or after defrosting. The plastic from which the inner panels are made must “get used” to freezing cycles. This process can take from several days to a couple of weeks of active use. If clicks are heard rarely and are not associated with turning on the motor, then, most likely, we are talking about thermal deformation structural elements.
The intensity of such sounds depends on the quality of the plastic and the rate of temperature change. Budget models may have thinner walls, making them more susceptible to thermal expansion. It is also worth considering that a sharp temperature change, for example, when loading a large amount of warm food, can enhance the “crackling” effect of the internal panels.
Sometimes users confuse the sounds of expansion with fan operation. To differentiate these processes, you need to know that thermal clicks do not have a strict frequency of activation, unlike mechanical components. If the noise becomes constant and intrusive, it is worth checking whether the internal shelves are touching the walls of the chamber, increasing the vibration.
Operation of the start relay and compressor
A more serious reason for the clicks lies in the “heart” of the refrigerator - the compressor. To start the engine, a special device is used - a starting relay. It is this that supplies a current pulse to the motor windings, causing it to rotate. When turned on, you can hear a distinct click. This is a normal phenomenon, indicating the operation of an electromagnetic or posistor mechanism. However, if the clicking becomes frequent and the refrigerator does not start or immediately stalls, the problem may be deeper.
Frequent clicking without subsequent starting of the motor often indicates a malfunction of the starting relay or compressor windings. The relay tries to start the engine, a click occurs, but due to overload or breakdown, the protection opens the circuit, and the process repeats after a certain time interval. In such a situation, operating the equipment is dangerous: the motor may burn out completely, which will require an expensive replacement of the entire unit.
It is also worth paying attention to the nature of the sound of the operating compressor. A working motor hums evenly. If metallic clangs, knocks or rhythmic clicks inside the motor housing are added to the hum, this may indicate mechanical wear of the piston group or bearings. In older models with open compressors, lubrication was sometimes required, while modern units are usually not maintained and must be replaced if they break down.
Diagnostics of the electrical part requires caution. If you are not skilled in working with electrical appliances, it is better not to open the back panel yourself. The technician will use a multimeter to check the resistance of the windings and the integrity of the relay contacts. Replacing a relay is an inexpensive and quick procedure, but it requires precise selection of a part for a specific compressor model.
Refrigerant circulation in the system
Another source of sounds that often frightens owners is the movement of refrigerant (freon) through the pipes of the cooling system. Liquid and gaseous refrigerant, moving under pressure, can make sounds similar to gurgling, hissing or light crackling. Sometimes these sounds are perceived as clicks, especially if there are bends or obstacles in the tubes that create turbulence in the flow.
It is important to understand that the system contains not only gas, but also oil, which circulates along with freon to lubricate the compressor. Oil bubbles passing through a capillary tube or evaporator can create a characteristic popping sound. Typically, such sounds are most audible immediately after the compressor stops, when the pressure in the system is equalized and the refrigerant continues to move by inertia or under the influence of pressure differences.
If the refrigerator has just been defrosted or a lot of food has been loaded into the chamber, the system begins to work in enhanced mode. At this point, refrigerant circulation is most active and sounds may be louder than usual. However, if the gurgling turns into a loud whistle or constant knocking, this may indicate clogging of the capillary tube or the presence of excess moisture in the system (water hammer).
| Sound type | Probable reason | Danger | Need for repair |
|---|---|---|---|
| Rare clicks of plastic | Thermal expansion | No | Not required |
| Click at start/stop | Relay operation | No (if the motor starts) | Not required |
| Frequent clicks without starting | Fault relay/compressor | High (risk of combustion) | Urgent |
| Gurgling and hissing | Freon movement | No | Not required |
| Metal clanging | Motor wear | High | Diagnostics required |
In some cases, circulation sounds may increase due to incorrect position of the refrigerator. If the unit is not level, oil can accumulate in one of the sections of the circuit, creating plugs and causing noise when gas passes through them. Adjusting the legs of the refrigerator often helps reduce the noise level.
Vibration and interaction with the environment
Often the source of clicks and knocks is not the internal device at all, but external factors. The refrigerator vibrates during operation, and this vibration is transmitted to the body, floor and nearby objects. If the unit is too close to a wall or furniture, vibration may cause periodic impacts of the housing against obstacles, which are perceived as clicks.
Check whether the rear condenser grill or the refrigerator body itself is touching the wall, cabinet or curtains. Even a minimal gap of a couple of millimeters can disappear during the active phase of compressor operation, causing knocking. It is also worth inspecting the space behind the refrigerator: small objects (coins, buttons, toys) could have fallen there, which, when vibrated, begin to jump and knock on metal parts.
Another source is loose elements inside. Shelves, drawers or bottles in the door may rattle and hit each other due to floor vibrations. Make sure that all shelves fit tightly into the grooves and that the products do not create resonance. Sometimes it is enough just to move the bottle or adjust the container so that the extraneous sound disappears.
☑️ Diagnosis of external causes of noise
Particular attention should be paid to the floor. If the surface is slippery (such as linoleum or tile), the legs of the refrigerator may “ride” slightly, causing periodic impacts. In this case, special anti-vibration stands or mats under the legs will help, which will also protect the floor covering.
Problems with the fan (for the No Frost system)
In refrigerators with the system No Frost the fan is responsible for circulating cold air. It is usually located in the freezer compartment or behind the back panel. If you hear clicking noises that are repeated with a certain frequency and coincide with the operation of the defrost system or active cooling, the problem may be in the fan.
Clicking noises are often caused by ice freezing on the fan blades or on the axis of its rotation. Ice interferes with free rotation, and the blades can touch ice or channel walls, producing a characteristic cracking or knocking sound. Also, a worn fan bearing can make sounds similar to clicks, especially when accelerating or stopping the motor.
In some models, the fan has protection: if its impeller is jammed with ice, the motor may try to turn, click and go into error. This often happens when the defrost heating element or defrost sensor is faulty, when too much ice accumulates in the evaporator. In this case, defrosting is required (complete, within 24 hours with the doors open) and, possibly, repair of the defrosting system.
⚠️ Attention: An attempt to manually turn a jammed fan or remove ice with sharp objects without defrosting can lead to damage to the blades or the evaporator. Allow the ice to melt naturally.
If, after complete defrosting, the fan clicks resume after a short time, this is a sure sign of a malfunction in the defrost circuit. The technician must check the resistance of the heating element, defrost sensor and timer (or electronic control module). Ignoring this problem will lead to the ice completely blocking the air channel and the refrigerator will stop cooling.
When you need to call a specialist
Despite the fact that many sounds are normal, there are situations when you cannot do without professional help. If clicks are accompanied by other alarming symptoms, you should not hesitate to call a specialist. These symptoms include: lack of cold in the chambers, continuous operation of the compressor without shutdowns, the appearance of ice in an unexpected place, or the smell of burnt wiring.
It is also worth contacting service if the frequency of clicks increases. For example, if previously the refrigerator clicked once an hour when turned off, but now it clicks every 5 minutes and does not start - this is a clear sign of a breakdown of the start-up relay or compressor. Replacing these components yourself is only possible if you have experience and tools, otherwise you can damage an expensive compressor.
Is it possible to ignore rare clicks?
If the refrigerator freezes properly, there is no excess ice inside, and the clicks are rare and quiet (thermal), then you can operate the equipment. However, it is worth observing the dynamics: if there are more sounds, diagnostics will be required.
Remember that timely repairs are often cheaper than replacing a burnt out motor or the entire refrigerator. The technician will be able to accurately determine the source of the sound using professional equipment and offer the optimal solution to the problem. Do not attempt to repair the electrical part yourself unless you have the appropriate qualifications.
Frequently asked questions (FAQ)
Why does the refrigerator click when it is not working?
Clicks when turned off are most often caused by thermal expansion of materials (plastic and metal) that cool or heat up to room temperature temperature. It could also be the sound of condensation draining or residual movement of the refrigerant when the pressure in the system is equalized.
Is it normal for a new refrigerator to click?
Yes, this is typical for new equipment. The plastic elements of the interior decoration have not yet “got used to” the temperature conditions, so thermal clicks may be more frequent and loud. Usually, after 1-2 weeks, the intensity of the sounds decreases.
Does the inverter refrigerator click?
Inverter compressors operate smoother and quieter than usual, they do not have the characteristic sound of starting and stopping, since they do not turn off completely. However, clicks of thermal expansion or sounds of fans are present in them to the same extent as in conventional models.
What to do if the refrigerator clicks and does not turn on?
First of all, unplug the device for 15-20 minutes to reset the electronics error and allow the compressor to cool. If after switching on the situation repeats (clicks and stalls), the start relay or compressor is likely damaged. You need to call a technician.
Can the temperature sensor click?
The sensor itself (thermostat) clicks only when the contacts open or close, which is accompanied by the motor turning on or off. If you hear a click and at the same moment the operation indicator lights up or goes out/you can hear the motor starting, this is the operation of the thermostat, which is the norm.