Modern systems No Frost have become the standard of comfort, eliminating the need for users to regularly defrost chambers manually. However, convenience often comes at the price of silence in the house: owners notice that The refrigerator makes a cracking soundclicks or hums much more often than older models with a drip system. Understanding the nature of these sounds is the first step to staying calm and extending the life of your appliances.
Do not panic if you hear an extraneous noise immediately after purchase or switching on. Most sounds that users describe as “crackling” are normal operation of the compressor, refrigerant, or automatic defrost system. It is important to learn to distinguish normal functioning the signs of an incipient malfunction that requires the intervention of a technician.
In this article we will analyze in detail the physical and mechanical causes of the crackling noise, consider the design of the system No Frost and provide an algorithm for self-diagnosis. You will find out when you can sleep peacefully, and in which cases you urgently need to call a specialist for repairs.
Physics of the process: why a working refrigerator cracks
The most common reason why the refrigerator is crackinglies in the banal laws of physics, namely, the thermal expansion of materials. The inner plastic body of the camera and the outer metal casing have different expansion coefficients. When there is a sudden change in temperature, for example, immediately after loading food or turning on the compressor, the materials react to heating or cooling at different rates.
This process is accompanied by a characteristic sound reminiscent of crackling or clicking. This phenomenon is especially common in new models or after long-term transportation. The plastic “gets used” to temperature conditions, and sounds become quieter over time or disappear altogether. This is absolutely a normal phenomenon, and does not require repair.
⚠️ Attention: If the crackling sound is accompanied by the appearance of an unpleasant smell of burning or plastic, immediately unplug the device. This may indicate overheating of the wiring or melting of the insulation.
It is also worth considering the quality of materials. In budget models No Frost manufacturers can use plastic with a smaller margin of safety, which reacts to temperature changes more loudly. Expensive brands, such as Liebherr or Bosch, use composite materials that reduce the level of acoustic noise during deformation.
Operation of the automatic defrosting system
The key difference between the system No Frost from the drip system is the presence an evaporator hidden behind the back wall of the chamber and a forced air circulation system. Periodically, usually every 8-12 hours of compressor operation, a defrost cycle is started. At this moment defrost heating element it heats up to melt the ice on the evaporator.
Sharp heating of the cold heating element and drops of melt water hitting the hot surface of the heater causes a characteristic hissing or crackling sound. It's similar to how a frying pan sizzles when water has been dropped on it. The sound can be quite loud and frightening for an unprepared user, but it only indicates that defrost cycle it is proceeding successfully.
In addition, at the moment of switching modes (end of cooling and start of defrost) it may trigger. data-i="80">or thermal relay or defrost timer. Mechanical switching of contacts inside these elements also produces a loud click. In modern inverter models, this sound is replaced by electronic control, but in classic systems it remains.
Duration of the defrost cycle
Usually the defrosting process in the No Frost system takes from 15 to 30 minutes. During this time, the compressor does not work and the fan may be stopped. If the rattling noise lasts longer than an hour, the defrost sensor may be faulty.
It is important to note that water draining into the drain pan above the compressor may also make sounds as it evaporates. The tray heats up from a running motor, and moisture, dripping onto its hot surface, makes short crackling sounds. This is the normal operating mode of the condensate evaporation system.
Mechanical reasons: fan and ice
If the physical cracking of plastic and defrosting sounds can be considered normal, then mechanical interventions often indicate a problem. In the system No Frost responsible for the circulation of cold air is fan. If an ice crust has formed on the blades or axis of the fan, it begins to work under load, producing a cracking, grinding or humming sound.
Ice can build up due to a loose door, damage to the seal, or a malfunction of the defrost sensor. The rotating blades touch the frozen ice, which creates a rhythmic cracking sound. In the long term, this leads to wear of the fan bushings and its complete stop, which threatens the defrosting of food.
- ❄️ Ice build-up: Check the back wall of the chamber. If ice or frost is visible, the system requires complete defrosting.
- 🌀 Fan play: Pump the impeller by hand (with the refrigerator turned off). If there is severe play or jamming, the unit requires replacement.
- 🔊 Sound character: Mechanical crackling is usually rhythmic and depends on the operation of the motor, in contrast to the chaotic crackling of plastic.
To eliminate this problem it is often enough defrost completely refrigerator over 24 hours, leaving the doors open. This will allow the ice in the duct system to melt. If, after turning on, the fan begins to make noise again after a few days, the problem lies deeper - probably the defrost sensor or heating element has failed.
☑️ Fan diagnostics
Problems with the compressor and refrigerant
The “heart” of the refrigerator - the compressor - can also be the source of the crackling sound. In classic models, one-time loud clicks may occur when starting and stopping the engine. It works start relay. If the click is accompanied by a hum, but the motor does not start, and after a while there is a second click and silence again, this is a sign of a malfunction of the starting mechanism or the compressor itself.
In addition, freon circulates through the tubes. When passing through narrow sections of a capillary tube or when there is a sudden change in pressure in the system, the liquid may gurgle, gurgle, or make quiet crackling sounds. This is especially noticeable in the quiet of the night. refrigerant (freon). When passing through narrow sections of a capillary tube or when there is a sudden change in pressure in the system, the liquid may gurgle, gurgle, or make quiet crackling sounds. This is especially noticeable in the silence of the night.
⚠️ Attention: If the crackling sound in the compressor area is accompanied by vibration that is transmitted to the housing and floor, check the transport bolts (if they were not removed during installation) or the adjusting feet. An uneven installation increases any sound from the motor.
In inverter compressors that operate non-stop, there is no crackling sound at start-up, but high-frequency sounds may appear when the speed changes. This is due to the operation of electronics and the magnetic field in the engine. Typically such sounds are described as “squeaking” or “buzzing”, but when combined with vibration they can be perceived as a crackling sound.
Sound Diagnostic Chart
To make it easier for you to determine the cause of the noise, we have systematized the main types of sounds and their likely sources. Use this table for an initial assessment of the condition of your equipment.
| Sound type | Probable cause | Status | Actions |
|---|---|---|---|
| Single loud click | Compressor start/stop, thermal relay | Normal | Observation |
| Chaotic crackling (like in a fire) | Thermal expansion of the plastic body | Normal | No action |
| Rhythmic crackling/grinding | The fan touches ice or a foreign object | Requires attention | Defrosting, checking the fan |
| Hissing and gurgling | Freon movement, system operation defrost | Normal | No action |
| Crackling noise with a burning smell | Wiring or relay fault | Danger | Emergency repair |
As can be seen from the table, most sounds do not pose a threat. However, if the sound changes over time, becomes louder or changes in character, this is a reason to listen more carefully to the operation of the unit. Diagnostics hearing is the first stage in identifying problems.
When a cracking becomes a symptom of a breakdown
There are a number of signs that clearly indicate that No Frost refrigerator it is faulty. If the crackling sound is accompanied by a lack of cold in one of the chambers, constant operation of the motor without shutdowns, or the appearance of puddles of water under the device, these are serious symptoms.
A frequent cause of mechanical crackling in this case is the failure of the blower fan bearings. Over time, the lubricant in them dries out, play appears, and the bushing begins to vibrate. Another option is deformation of the plastic air ducts inside the case due to overheating or manufacturing defects, due to which the air flow causes them to vibrate and knock on the walls.
It is also worth paying attention to the condition door seal. If the rubber becomes dry or dirty, warm, moist air enters the chamber. This leads to increased formation of ice on the evaporator, which, in turn, begins to crack and interfere with the operation of the fan. Regularly washing the seal and checking the tightness of the door is a simple prevention of complex problems.
⚠️ Attention: Do not try to disassemble the back panel inside the freezer yourself if you do not have skills in working with electronics. There are fragile sensors and heaters, damage to which will lead to expensive repairs.
Prevention and proper care
In order for your refrigerator to serve for a long time and delight you with silence, it is important to follow the operating rules. Do not put hot food inside - this causes a sharp rise in temperature and increases the cracking of the plastic. Make sure that the food does not touch the back wall of the chamber, where the air duct openings are located.
Regularly, at least once every six months, completely defrost the system, even if the manufacturer claims the system No Frost. This will help clean hidden cavities from dust deposits and residual moisture, which over time can turn into ice plugs. The cleanliness of the drainage hole also plays a key role in silent operation.
Installing the refrigerator on a flat surface using a building level will help avoid vibrational hum, which often disguised as crackling. Adjusting the legs is a simple operation that can be performed by any user, and it has a significant impact on the acoustic comfort in the kitchen.
Why does a new refrigerator rattle more than an old one?
New models often have thinner cabinet walls to increase usable volume and better thermal insulation. In addition, modern refrigerants can operate at slightly different pressures. The period of “grinding in” of materials can last up to several months.
Can a crackling sound be a sign of a freon leak?
A freon leak itself usually does not make sounds. However, if the leak is caused by vibration and friction of the tubes against each other (which may be accompanied by a metallic grinding sound), then there is a connection. More often, a leak occurs due to corrosion or a factory soldering defect and is not audible to the ear.
Does the voltage in the network affect the crackling sound of the refrigerator?
Yes, low voltage in the network can make it difficult to start the compressor. The engine will hum, try to start, click the protection relay and stall again. This creates a characteristic intermittent crackling and buzzing sound. In such cases, a voltage stabilizer is needed.
How to distinguish the crack of plastic from the crack of ice?
The crack of plastic is usually more loud, short and chaotic, often occurring in volleys. The cracking of ice (fan operation on ice) is more dull, rhythmic and often coincides with the cycles of turning on the motor or defrosting.
Do you need to call a technician if the refrigerator is just cracking?
If the cold remains, the food does not spoil, and the cracking sound is similar to clicks or the noise of expanding plastic - calling a technician is not necessary. If you hear the grinding of metal, the rhythmic knocking of a fan, or smell a burning smell, repairs are necessary.