Noise (hissing, gurgling, cracking, clicking, rattling, thumping & humming)
Refrigerators have this uncanny habit of being just about as noisy as the human body experiencing digestion issues and bones cracking.
Most of the noises listed below are considered casualties of normal daily operation.
Cause and Symptoms
Hissing noise from evaporator coil frost buildup melting.
➔ When cold refrigerant flows through the evaporator inside the refrigerator, frost forms around the evaporator from being struck by ambient warm air.
In other words, as the refrigerant travels through the evaporator, it absorbs heat from the air. As it absorbs heat, it vaporizes. A by-product from that is frost forming on the outside of the evaporator coil.
At which point, defrosting (ice buildup removal) is carried out to remove the accumulated frost. As a result, dripping water from the evaporator hits the heater below. It vaporizes instantly thus making a hissing noise.
The heater runs to defrost the inside of the refrigerator at regular intervals.
During that time, the refrigerator compartment internal temperature rises temporarily. This process is referred to as defrosting.
So, any water dripping sound can also be heard from the frost buildup melting away.
Additionally, water dripping on the heater will generate some noise.
This may be perceived as if water is encountering a running heating element and evaporating [hissing]. Rest assured as it is not a product defect.
Hissing or gurgling noise?
➔ These are natural sounds occurring from the oil and refrigerant flow inside the coils when the compressor is running to produce frigid air.
In order to generate cold air so to extract and remove warm air, without overheating, a refrigerant is necessary to lower the temperature inside the refrigerator.
This refrigerant, initially in a liquid state, is no surprise that it can make hissing and gurgling noise just as water flushes down through a drain.
Cracking, clicking and water dripping noise?
➔ Cracking, clicking and water dripping noise are natural sounds made by plastic parts such as inner panels, crispers and bins expanding or contracting when the temperature inside the refrigerator changes.
As the temperature changes, thermal contraction and expansion occur inside the refrigerator, causing some noise. Cracking can get pretty loud at times.
It's very similar to the principle of making instantaneous cracking sound when ice melts.
Hissing noise (air leaking out)?
➔ By opening and closing refrigerator door, warm air penetrates while cool air escapes causing pressure inside to change.
At that very moment, cool air, which tends to hover below warm air, escapes the refrigerator compartment, and thus creates noise.
When the door gets opened, outside warm air encounters cold air inside the refrigerator. That alone creates a difference in the pressure inside the refrigerator.
Rattling, thumping and humming noise?
➔ Rattling, thumping, and humming noise are the sounds from the cooling engine (compressor) or the fan when the compressor resumes operation after stopping.
Once the temperature inside the refrigerator has stabilized, noise will gradually attenuate.
Same as when you start a vehicle. Loud noise and intense vibrations occur at first, but the noise and vibrations gradually decrease after the engine warms up.
Additionally, humming, buzzing, and whizzing noise can be heard from the process of producing cold air.
In addition, noise may be temporarily perceived more significantly from the process of generating pressure differences as the refrigerant flows inside the refrigerator coils.
This is all absolutely natural that audible sounds are being produced while the refrigerator compressor is operating. Rest assured as it is not a product defect.
This guide was created for all refrigerator type models. Images or content presented herein may differ from your product.
