No household appliance is completely silent, including refrigerators. Refrigerators require the use of a motor and compressor to work and cool properly as well as water that enters the refrigerator through supply lines to create ice and dispense both water and ice in many units. If a refrigerator is making a humming noise, this may not necessarily be cause for concern, but some troubleshooting might be useful.
Normal Ice Maker Sounds
Many refrigerators have an automatic ice maker that creates ice cubes and fills a bin on a constant basis. When the ice maker fills with water, it can make a humming noise. If this noise only happens when the ice maker fills with water, the sound is normal and is not indicative of a problem.
Ice Maker Humming
A loud humming or buzzing noise that occurs on a constant basis, such as every 15 minutes or so, might actually indicate a problem with the ice maker. Verify that the ice maker is turned on and that the water supply lines are firmly connected to the refrigerator. If the ice maker is turned on but there is no water supply, the ice maker will hum loudly and may eventually become damaged if water does not enter the unit.
Another potential cause of humming is if items have been placed too close to the air vents along the sides and back of the refrigerator. Items may rattle against the walls and prevent proper airflow, creating a humming sound. Keep a space between food items and the air vents for proper air movement and to reduce humming or rattling.
The compressor on the refrigerator may get dirty over time, causing a humming sound during operation. To resolve this situation, disconnect power to the refrigerator and remove the panel in the back. Use a soft brush to clean the condenser fan and the compressor. Replace the panel, and restore power to the unit.