Beko BBBF2410IM 22" Built-in Bottom Freezer Refrigerator

It is recommended that you defrost your refrigerator's freezer unit approximately once a month or when the frost build-up reaches a thickness of a quarter inch.
No-frost refrigerators do not need manual defrosting.

It is normal to hear noises that resemble the sound of running water as your refrigerator is running. These sounds are made when liquid and gas flow inside the refrigerant system. This is not a malfunction.
The sound could also be coming from the water supply if your refrigerator has an ice maker, or from the automatic defrosting function if your appliance is a no-frost model. Try to determine where the sound is coming from. If it is coming from the freezer area or between the water supply and the ice maker, the sound is normal and will stop automatically after a while.
If your appliance isn’t operating normally while making this noise, contact an authorized service agent.

The sound you're hearing is the door open alarm. If the refrigerator door or doors are left open, the door open alarm will be activated in a few minutes. As soon as you close the door, the alarm will turn off.

It is normal to hear a cracking sound as your refrigerator is running. This sound could be coming from the refrigerator components contracting or expanding, or from falling ice cubes if your refrigerator is equipped with an ice maker. This is likely not a malfunction.
If your appliance is not operating normally while making this noise, consider contacting an authorized service agent.