CloseFirst and foremost, follow the manufacturer's instructions to clean a humidifier. It is important to clean the humidifier regularly to remove lime scale caused by water minerals which collect on the belts, the water reservoir and other parts that come in contact with the water.
Regular use of a liquid water conditioner solution will help to control odor and simplify cleaning. Some units have dispensers which store and then dispense the solution directly into the reservoir water.
As air passes through the pad, some particles of dirt are trapped; also, the pad may become heavy with hard water particles which collect on the fibers of the pad as the water evaporates. Even if the interior liner and other functional parts are made of non-corrosive materials, rust can result from iron in the water.
The pad, liner and other interior parts need to be cleaned frequently. Be careful when putting parts back together so no malfunction will occur. Some humidifiers have drain outlets--others have to be operated until all the water is removed before cleaning.
Cleaning the humidifier outdoors or in the basement with the use of a hose may make it unnecessary to take the pad off the holder, but there is the possibility that water may get into the motor or controls. Plastic parts may be damaged if hot water is used to fill the tank. Pads may wear out or become ineffective. Once-a-year replacement may be warranted.
Between operations, the unit should not be stored or left for long periods with water in it. Undesirable odors from the growth of fungus and bacteria can develop.