How to Clean a Humidifier

Updated: Feb. 15, 2024

Here's our expert guide for how to clean your humidifier, the common household cleaning supplies to do so and why you should clean your humidifier often.

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clean humidifier
Family Handyman

How Often Should You Clean a Humidifier?

We consulted with MaidPro cleaning expert Melissa Homer for the inside scoop on the proper way to clean a humidifier. Here are her recommendations.

Homer explained that to maintain top performance and control mold growth, humidifiers should be rinsed and refilled daily and deep cleaned weekly. If you don’t have hard water, you might be able to get by with deep cleaning every other week. But, if you notice any active mold growth or sliminess, revert back to weekly deep cleaning. “The key with humidifiers is to keep doing the daily and weekly cleaning religiously, so that it is quick, easy and virtually scrub free,” she says.

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pouring out water from humidifer
Family Handyman

How Often Should You Change the Water?

If you leave water sitting in the water reservoir of a humidifier for long periods of time, it will result in mineral deposits and mold growth—so change the water every day. The longer the water sits, the more growth there will be and the harder it’ll be to remove.

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clean a humidifier
Family Handyman

How to Clean a Humidifier

Empty, rinse and refill the water reservoir daily. Once a week, follow these steps for a deeper clean to eliminate dust and other buildup. If you stick to weekly deep cleaning, all you’ll need is a microfiber towel and white vinegar.

  1. Unplug and empty the humidifier water reservoir.
  2. Dampen a towel with vinegar and thoroughly wipe out the inside of the water basin (the base of the humidifier that the water reservoir sits in).
  3. To descale and reduce mold growth, refill the reservoir halfway with warm water and add 1/4 cup of vinegar. Close the reservoir, set it in the basin and let it soak for 30 minutes.
  4. Now, rinse out everything, refill with fresh water and plug in the humidifier.
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disinfect humidifier
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How to Restore a Neglected Humidifier

If you’ve ignored your humidifier for a while and have hard water deposits and mold, add a baby bottle brush, a thin straw brush, dish soap and some bleach or hydrogen peroxide to your cleaning kit. Mix two tablespoons bleach (or 1/2 cup hydrogen peroxide) and a couple drops of dish soap in a bowl. Using your towel and brushes, scrub away all visible signs of mold and slimness inside the basin and reservoir nooks and crannies. Be mindful not to splash water into any knobs, fans or mechanical components. Pour some of the bleach water into the reservoir, shake it around vigorously and let it sit for at least 10 minutes. Once the unit is visibly clean, thoroughly rinse and wipe dry. Follow the weekly reservoir descaling process described in the previous slide and you shouldn’t have to do this process again.

Note: When deep cleaning and descaling, make sure bleach and vinegar never come in contact with each other, even diluted, as toxic chlorine gas can result.

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Humidifier Maintenance and Safety

If your humidifier is more than five years old, consider getting a new one. Also, keep the area around the humidifier dry. Too much humidity can lead to mold growth and window condensation inside your home. Indoor humidity should be at a level of 30 to 50 percent. If the area around your humidifier is damp, dry everything with a towel and try only running the humidifier at night.

When it’s time to put your humidifier away, clean it thoroughly and make sure it is completely dry. When you take it out again next winter,  clean it before its first use.