A sudden click or prolonged crackling sound when starting the unit is a signal that makes any owner of household appliances wary. Often, users confuse normal physical processes with signs of a serious breakdown, which leads to unnecessary panic or, conversely, to ignoring the real problem. Noise when turned on can be caused by many factors: from the banal expansion of materials to the failure of the electrical circuit.
To understand the nature of the sound, it is necessary to analyze its nature, duration and frequency of occurrence. If refrigerator makes a sound only in the first seconds after the relay clicks, that's one thing. If the crackling continues throughout the entire operation of the engine or is repeated chaotically, this is a completely different scenario that requires a detailed analysis. In this article we will analyze in detail the mechanical and electrical causes of extraneous sounds.
It is important to immediately note that modern models, especially with inverter compressors, may sound different than old Soviet units. Acoustic comfort today is one of the priorities of engineers, but completely silent equipment is not exists. Understanding the principles of operation of the cooling system will help you quickly determine whether you need the help of a specialist or just wait.
⚠️ Attention: If the crackling sound is accompanied by a burning smell, sparking, or a complete refusal of the equipment to turn on, immediately disconnect the device from the power supply to avoid a short circuit or fire.
Thermal expansion of housing materials and tubes
The most common and completely harmless cause of cracking is a physical phenomenon known as thermal expansion. When compressor starts up, the refrigerant begins to circulate through the system, dramatically changing the temperature of the metal tubes and plastic elements of the internal circuit. Materials react to temperature changes by changing their volume, which causes a characteristic sound.
Usually this process is accompanied by sounds reminiscent of the crackling of wood in a fireplace or a slight clicking sound. This is especially pronounced in models with No Frost, where the plastic of the inner box cools very quickly. In most cases, such noise occurs precisely at the moment the unit is turned on or off, when the temperature difference is maximum.
The intensity of the sounds may depend on the quality of the plastic used by the manufacturer and the cooling rate of the evaporator. If your refrigerator is standing on an uneven floor, the vibration from the expanding parts may increase, creating a resonating effect. Over time, when the internal chamber cools down to the set temperature, the sounds should stop completely.
It is worth considering that in new models this effect may be more noticeable in the first months operation until the materials go through the cycle of initial “grinding in” of temperature conditions. If the crackling noise is heard only when the engine starts and subsides after 10-20 seconds, there is no cause for concern.
Malfunctions of the starting relay and electrical circuit
If the nature of the sound changes to a loud, sharp click or a series of quick crackling sounds, followed by a hum and subsequent stopping of the motor, the problem most likely lies in electrical. Start relay is a device that provides the initial impulse to start the engine. If it malfunctions, the contacts may stick or burn, producing a distinct crackling sound.
At the moment of switching on, the relay should operate once. If you hear a series of clicks (click-click-click), this means that the automation is trying to start the compressor, but is unsuccessful. After several such attempts, the thermal protection is triggered and the motor stalls. Restarting is possible only after the thermocouple has completely cooled down.
The main symptoms of electrical problems include:
- 🔌 A loud metallic click at the rear of the unit when trying to start.
- 🔌 Lack of cooling inside the chambers despite the working fan.
- 🔌 Heating of the compressor housing in the absence of cold.
- 🔌 Periodic switching on and off with an interval of 2-3 minutes.
Replacing the relay is an inexpensive and quick procedure, but requires accurate diagnosis. Sometimes the cause of the crackling sound is not the relay itself, but one that has lost its capacity. In this case, the engine does not have enough energy to start, and it hums until the protection is activated. starting capacitorwhich has lost its capacity. In this case, the engine does not have enough energy to start, and it hums until the protection is triggered.
How to check the relay yourself?
For diagnostics, you can carefully remove the relay from the compressor rod and shake it. If you can hear the ringing of scattered parts inside, the element is definitely faulty and requires replacement.
Problems with the compressor: jamming and wear
The most serious reason for the crackling noise when turned on is a mechanical malfunction of the very heart of the refrigerator, compressor. Inside the sealed housing there are pistons and valves, which, if worn out or foreign objects enter, can produce grinding and cracking noises. If the motor hums strainedly, and then there is a loud knock or crackling sound and it goes silent, this is a sign of jamming.
Often such situations arise after a long period of equipment downtime or during power surges in the network. Mechanical jamming of the piston group does not allow the shaft to rotate, and the engine, trying to overcome the resistance, makes a characteristic sound. In some cases, “boosting” the compressor by applying increased voltage helps, but this is a job for professionals.
Symptoms of critical compressor wear:
- ⚙️ The motor tries to start, but makes the sound of a “heavy sigh” or growling.
- ⚙️ A metallic clang is heard inside the motor housing.
- ⚙️ The compressor housing overheats in a short time of operation.
- ⚙️ Automatic plugs or RCDs in the electrical panel are knocked out.
If diagnostics have shown that the problem is in the compressor, repairs are often economical impractical, since replacing the motor is expensive. However, if the unit is under warranty or is a premium model, restoration makes sense.
⚠️ Attention: Never try to depressurize the compressor yourself or open its housing - there is oil and refrigerant under pressure inside, which can be dangerous.
Vibration and resonance of external elements
Sometimes there is a cracking sound when turning on has nothing to do with internal processes, but is caused by poor installation of equipment. When compressor starts working, it creates a vibration that is transmitted to the body, floor and nearby objects. If the refrigerator is not level or touches furniture, a resonating cracking sound occurs.
Check the adjusting feet: they should be tightly screwed in and ensure a stable position. The gap between the back wall of the refrigerator and the kitchen wall should be at least 5-7 cm for free air circulation and no contact of vibrating tubes with the wall.
Also, loose elements inside can become a source of sound:
- 🍽️ Dishes standing close to the walls of the chamber.
- 🍽️ Shelves that are not fully inserted into the guides.
- 🍽️ Bottles in the door that knock against each other when vibrating.
- 🍽️ Decorative magnets on the outer wall that rattle.
☑️ Vibration diagnostics
Particular attention should be paid to the condensate collection tray, which is located above the compressor in the lower rear part. If it is not installed tightly or is skewed, when the engine starts, it will vibrate and make an unpleasant rattling sound, which can easily be mistaken for the crackling of the mechanism.
Comparison table: Normal or broken?
To make it easier for you to navigate the types of sounds and their meaning, we have prepared a summary table. It will help you quickly classify the problem and decide on further actions.
| Sound type | Time of occurrence | Probable cause | Status |
|---|---|---|---|
| Quiet crackling | When turned on/off | Thermal expansion of plastic and metal | Normal |
| Loud click + buzzing | At the moment of start | Malfunction of the starting relay | Repair required |
| Metal grinding | Constantly during operation | Compressor wear or contact | Critical |
| Rattling | When the motor is running | Case vibration or poor installation | Adjustment |
| Series of clicks | Cyclic every 2-3 minutes | Attempts to start when jammed | Repair required |
By analyzing the table data, you can with a high degree of probability determine the severity of the situation. Remember that auditory diagnosis this is only the first stage, which does not replace a professional examination.
Specifics of operation of inverter compressors
Owners of modern refrigerators with inverter type controls can hear sounds that are absent in classic models. Such compressors do not turn off completely, but only reduce the speed, so the moment they are “turned on” (transition to high speed) may be accompanied by a specific hum or slight crackling sound.
Inverter systems are more sensitive to voltage drops and power quality. If your network experiences spikes, the electronics may be trying to adjust the motor's operation, sometimes causing audio artifacts. In such cases, it is recommended to use a voltage stabilizer.
Features of the sound of inverters:
- 🎛️ The sound may resemble flowing water or hissing even in standby mode.
- 🎛️ With a sharp increase in load (loading warm products), the sound is amplified.
- 🎛️ There is no characteristic loud shutdown click, as in older models.
If your refrigerator equipped with a digital display, in case of sound anomalies it is worth checking the error code. Modern models often display diagnostic codes indicating problems with the fan or sensors, which indirectly affect the operation of the compressor.
⚠️ Attention: Specifications and error codes may vary depending on the manufacturer and model. Always check the official user manual for your specific series of equipment.
Algorithm of actions when a crack is detected
If you hear a suspicious sound, do not immediately call a technician. First, conduct an independent initial diagnosis, which will help save time and money. A clear action plan will allow you to weed out false alarms.
First of all, listen: is the sound coming from inside the camera or from behind? If it's behind you and it sounds like plastic cracking, wait 15 minutes. If the sound is electrical (clicking), check the outlet and power cord. Make sure that the plug is inserted tightly and there are no signs of melting.
Next follow these steps:
- Unplug the refrigerator for 10-15 minutes to reset the protection error.
- Check the stability of the case and the absence of contact with the kitchen walls.
- Turn on the unit again and watch the first start-up cycle.
- If the cracking noise repeats and there is no cold, get ready to call a specialist.
Timely contacting professionals in the presence of electrical symptoms (relay clicks, knocking out plugs) can save the compressor from complete failure. A motor that tries to start for a long time with a faulty starter runs the risk of completely burning out.
Is it possible to operate a refrigerator if it makes a cracking noise when turned on?
If the crackling noise is caused by thermal expansion (quiet, short), it is possible. If you hear relay clicks, a humming sound without starting, or a metallic grinding sound, operation should be stopped, as this can lead to a fire or complete failure of the equipment.
How much does it cost to replace the starting relay?
The cost of the part itself is usually low, but the price consists of the cost of the spare part, the technician’s visit, and the replacement work. On average, repairs cost 15-25% of the cost of a new budget refrigerator.
Why did the old refrigerator begin to crack, although it was silent before?
Over time, the plastic dries out and becomes harder, increasing the sounds of expansion. The rubber shock absorbers under the compressor also wear out, which is why vibration is transmitted to the body more strongly than in a new device.