How to Keep Old Humidifiers Clean

Run the old humidifier with distilled or demineralized water instead of tap water. Tap water has minerals in it that will build up inside the humidifiers and promote the growth of bacteria.

Change the water in the humidifiers every day. This prevents film and other mineral deposits from building up inside the humidifiers.

Unplug the humidifier, and pour one cup of undiluted white vinegar directly into the base unit of the humidifier with the misting chamber sitting inside the base.

Let the white vinegar sit and soak in for at least 30 minutes. Occasionally shake the unit to make sure the vinegar covers the entire base.

Remove the base unit from the humidifier and use a soft bristled brush or a clean toothbrush to gently brush off all the mineral deposits around the coils.

Pour cold water directly down into the humidifier base with the misting chamber sitting in the base. Let the misting chamber sit in the water for a few minutes to help loosen the residue buildup.

Wipe off the residue from the misting chamber using a soft cloth. Wipe the chamber until it is dry.

Pour the rest of the water from the base down the drain.

Rinse the humidifier with clean water until the mineral and vinegar residue is gone. Rinse again to make sure the residue is gone.

Disinfect old humidifiers by filling the base with clean water and adding one teaspoon liquid chlorine bleach for each gallon of water in the base.

Let the bleach solution sit for at least 30 minutes, occasionally swishing the solution around to evenly coat the entire base.

Pour the bleach solution down the drain. Rinse the base several times with clean water until the bleach odor is gone.