How to Clean Your Humidifier

Keep mold from growing in the tank and blowing into the air in your home

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humidifier illustration with water vapors in air above it Illustration: iStock

A humidifier in your home can prevent dry, itchy skin. The moisture it pumps into the air can reduce the likelihood that people in your household will suffer from dry sinuses, nosebleeds, and cracked lips, the Mayo Clinic says. And a humidifier can mitigate the symptoms of colds and respiratory ailments.

But a humidifier that’s not maintained? It can be unhealthy.


Among other potential risks, a humidifier that isn’t thoroughly cleaned can propagate and spread unhealthy mold spores that are a problem especially for people with mold allergies, according to the American Academy of Allergy Asthma & Immunology. 

Several models in our humidifier ratings come with claims that they resist microbial growth. CR hasn’t tested those claims. Instead, we recommend that as matter of course you clean your tank regularly to reduce the risk of mold and other problems. We’ll lay out the steps below.

If you haven’t already purchased a humidifier, find one in our ratings that’s not only effective but also easy to clean. That’s reflected in our convenience score.

What to Do Daily and Weekly

To prevent the growth of mold and other contaminants, we recommend rinsing, towel-drying, and refilling your humidifier’s tank with fresh water daily. Once a week the tank and the base’s well need a deeper cleaning and sanitizing. Replace filters and wicks according to the maker’s recommended schedule. 

Some manufacturers suggest using bleach to sanitize. That approach can be effective, but James Dickerson, PhD, CR’s chief scientific officer, points out it has risks. “Bleach can degrade some plastics and seals that keep the unit watertight and structurally sound,” he says.

Here’s the routine Consumer Reports recommends:

What You Need
• Water.
• Towel.
• Distilled white vinegar.
• Empty bottle or measuring cup.
• Toothbrush, cotton swabs, or another gentle cleaning tool.

Remove the Tank From the Base

To the well of the base, add either 1 cup of vinegar or ½ cup each of vinegar and water.

Remove humidifier tank from base.

Illustration: Guilherme Henrique Illustration: Guilherme Henrique

Use the Cleaning Tool

Reach into crevices and scrub off scale in the well. Rinse until no vinegar smell remains. Towel dry.

Cleaning tool reaching into crevices and scrub off scale in
the well of humidifier.

Illustration: Guilherme Henrique Illustration: Guilherme Henrique

Pour 1 Cup Each of Vinegar and Water Into the Tank

Cap the tank and let soak for 20 minutes, swishing or shaking periodically. Pour out solution and rinse until no smell remains. Towel dry.

Pouring cup each of vinegar and water into the humidifier tank.

Illustration: Guilherme Henrique Illustration: Guilherme Henrique

What to Do Seasonally

When you’re ready to store your humidifier, first dry it thoroughly. And after taking it out of storage, fill the tank only when you’re ready to use it.

Need a New Humidifier?

Do you find your current humidifier a challenge to keep clean? Here are models that rate well in our tests for convenience. Each model’s convenience score reflects ease of cleaning as well as the unit’s weight, how easy the tank is to empty and fill from a bathroom or kitchen sink, and whether its parts can be put into a dishwasher. (You can filter the ratings to find models with higher convenience scores.)

For Small Rooms

(26 to 299 sq. ft.)

For Medium-Sized Rooms

(300 to 499 sq. ft.)

For Large Rooms

(500 to 999 sq. ft.)


(1,000 sq. ft. or more)

Tobie Stanger

I cover the money side of home-related purchases and improvements: avoiding scams, making sense of warranties and insurance, finding the best financing, and getting the most value for your dollar. For CR, I've also written about digital payments, credit and debit, taxes, supermarkets, financial planners, airlines, retirement and estate planning, shopping for electronics and hearing aids—even how to throw a knockout wedding on a shoestring. I am never bored. Find me on Twitter: @TobieStanger