There can be several reasons why your refrigerator makes noise periodically. Here are a few possible explanations:
Compressor cycling: The compressor is a crucial component of a refrigerator and is responsible for circulating refrigerant and maintaining the desired temperature. It periodically turns on and off to maintain the set temperature. When the compressor kicks in, it can produce a humming or buzzing sound, which is normal operation.
Defrost cycle: Many modern refrigerators have an automatic defrost cycle to prevent the buildup of frost on the evaporator coils. During the defrost cycle, the refrigerator temporarily shuts off the cooling mechanism and activates a heating element to melt the accumulated ice. This process can generate some noise, such as cracking or hissing sounds, which are generally brief and intermittent.
Fan operation: Refrigerators often have fans that help circulate air inside the appliance. These fans can turn on periodically to maintain proper airflow and cooling. The fan motors can produce humming or whirring sounds when they are running.
Water valve: If your refrigerator has a built-in ice maker or water dispenser, it may periodically activate a water valve to fill the ice tray or provide water. The sound of the water valve opening and closing can be audible.
Expansion and contraction of materials: Temperature variations inside the refrigerator can cause the materials, such as the plastic or metal components, to expand or contract. This expansion and contraction can sometimes result in creaking or popping sounds.
While some noise is normal for refrigerators, excessive or unusual noises could indicate a problem. If you notice loud or persistent noises, it may be worth contacting a technician to inspect your refrigerator and ensure everything is functioning properly.