Any object that holds water for an extended time can fall victim to lime scale buildup. Humidifiers hold water in a reservoir and convert it to a mist, adding moisture to the air in a room. While the devices are pretty straightforward and often only need to be refilled with water, periodic descaling removes excessive minerals and any accumulated mold spores. The wet walls of a humidifier reservoir provide a haven for mold spores, and mold in a humidifier can lead to itchy eyes and breathing problems, according to Consumer Reports. The acid in vinegar cuts through mold and lime scale.
Unplug the humidifier. Pour out any remaining water, then dry the inside of the reservoir using a clean cloth.
Fill the humidifier with white vinegar. Do not dilute the vinegar with water. Replace the cap on the reservoir tank.
Allow the vinegar to sit in the humidifier for at least 30 minutes; for better results, leave it overnight.
Pour the vinegar out of the humidifier. Dump it down a sink, or pour it into a container to reuse for future descaling.
Dampen a clean cloth. Wash the inside of the humidifier thoroughly to remove any remaining vinegar.