How to Clean a Humidifier

Use our tested process and tips for cleaning and disinfecting a humidifier to keep your home healthy.

What You Need

White distilled vinegarSoft-bristled brush or toothbrushLiquid chlorine bleachWater

Step 1: Disassemble Humidifier

You’ll need to take apart your humidifier to make sure each piece gets a thorough cleaning. Unplug the machine, empty the water tank, and detach any removable parts. If your humidifier has an air filter, remove that as well. You’ll know it’s time to replace the filter if it develops a hard crust or gives off an odor.

Step 2: Clean Humidifier with Vinegar

Pour enough white vinegar into the humidifier tank to cover areas that most often come in contact with water. Depending on the size of your humidifier (and how long you’ve gone between cleanings), you can also choose to dilute the vinegar with warm water for a less concentrated cleaning solution. Place smaller pieces, such as the tank cap, into a large container filled with vinegar to soak. Wait at least 20 minutes to allow the vinegar to break down any scale buildup, suggests Sarah Drake, the brand manager for seasonal humidifiers at Honeywell. Then, empty your humidifier and use a soft-bristled brush to clear away any residue. For hard-to-reach corners and crevices, a toothbrush works well for scrubbing or a brush with a flexible head.

Step 3: Disinfect Humidifier

After cleaning the humidifier with vinegar, Drake suggests using a bleach solution to kill any lingering bacteria. Mix 1 teaspoon of liquid chlorine bleach with 1 gallon of cold water, and fill the humidifier tank about halfway. Swish the solution around to coat the inside and let it stand for 20 minutes.

Step 4: Rinse with Water and Let Dry

Place each piece of the humidifier under running water, rinsing several times until the smell of bleach is gone. Let the parts air dry before you reassemble. Repeat this cleaning process at least once a week and again before you store it at the end of the dry season.

How Often to Clean a Humidifier

To keep your humidifier clean, it’s important to keep up the maintenance on a daily basis. “First, it’s best to empty the water tank and refill with fresh water daily,” Drake says. “If you think about it, the mist coming out of your humidifier is created from your water, so fresh water will provide fresh mist.” Empty the humidifier of standing water each day, rinse it out, and refill with new water before you turn it on. The type of water you use in your humidifier is also important. “If you have hard water, the minerals in the water have to go somewhere,” Drake says. Depending on the type of humidifier you’re using, those minerals can show up as white dust surrounding the machine or hard deposits stuck on the humidifier’s filter or heating element. To prevent buildup, Drake suggests adding a demineralization cartridge designed for your machine or using only distilled water inside the humidifier. Humidifiers help keep your home comfortable in cooler weather when the air gets dryer, but they require some upkeep to continue running smoothly. With these humidifier cleaning tips, you can keep your machine in top shape, and ensure the moisture it’s pumping out is always fresh and clean.