How to Clean a Humidifier

Disclosure: By clicking on the product links in this article, Mattress Nerd may receive a commission fee at no cost to you, the reader. Read full disclosure statement.

Humidifiers are a wonderful way to add moisture to your home in cold or dry months. But they’re also a damp environment that can get gross quickly. 

Without regular cleaning or disinfecting, humidifiers can become a breeding ground for bacteria, mold, and other potentially harmful microorganisms.

Keep reading to learn how to clean a humidifier, and how often you’ll need to do it.

Why Do You Need to Clean Your Humidifier? 

The Environmental Protection Agency (EPA) recommends disinfecting a humidifier every 3 days. This may seem like overkill, but it’s worth the extra effort.

Humidifiers are the perfect breeding ground for a slew of microorganisms like bacteria and mold. These can trigger symptoms in folks who have respiratory conditions like asthma, allergies, or COPD. Even those without a chronic condition can experience flu-like symptoms or a respiratory infection from inhaling them.

In severe cases, a dirty humidifier can lead to something called humidifier lung, a type of hypersensitivity pneumonitis (HP). Some studies show that humidifier lung can present like an acute respiratory illness. Some possible symptoms include:

  • fever
  • cough
  • fatigue
  • sore throat
  • congestion
  • runny nose
  • body aches

There isn’t enough existing research to fully understand the effects of humidifier lung, but it is clear that it can get serious. If you experience severe cold symptoms or have difficulty breathing, talk to your doctor.

How to Clean your Humidifier with Vinegar

Vinegar is an affordable and effective way to clean and disinfect a humidifier.

1. Prep the Humidifier

Unplug your humidifier and take the water tank off the base.

2. Disinfect Your Humidifier

Pour 1 cup of undiluted white vinegar directly into your humidifier’s water tank. Fill the rest of the tank with water and place it back on the base.

Let the vinegar solution sit for 20 to 30 minutes. Then drain.

For larger units, use 2 cups of white vinegar.

3. Rinse It Out

Once you’ve drained your water tank, use a soft dish brush to remove any remaining mineral buildup or debris. Then rinse the tank out with tap water until the vinegar smell is gone.

4. Reassemble 

Fill the tank with water and put it back on the base. Then plug it back in and enjoy!

Repeat this process at least once a week – but every three days is best.

How to Clean your Humidifier with Bleach

Using a bleach solution is a great way to destroy stubborn bacteria, mold, and other microorganisms. Unlike vinegar, you don’t have to use it every 3 days. Instead, do a deep clean every 2 to 4 weeks, depending on how often you use your humidifier. Make sure you’re

1. Prep the Humidifier

Take apart your humidifier. Each piece needs to be thoroughly cleansed, and it’s a lot easier to do that when it’s disassembled. After that, unplug the unit and pour out any water that’s left in the tank.

If your unit has an air filter, do not clean it with harsh chemicals. Bleach can dissolve the antimicrobial coating and reduce its ability to filter out the yucky stuff. If you notice a slimy film or crust around the filter, it’s time to get a new one.

2. Make Your Cleaning Solution

Mix 1 teaspoon of liquid chlorine bleach with 1 gallon of cool water. Once that’s done, grab an old toothbrush and a soft-bristled dish brush.

3. Disinfect Your Humidifier

Pour three-fourths of the cleaning solution into the tank of your humidifier. Reserve the other one-fourth of the solution for later. 

Swish the solution around to coat all of the edges. If you notice any buildup inside the tank, use your dish brush to scrub it off. Then let the tank stand for 20 to 30 minutes.

As the bleach does its job in the tank, take this time to sanitize the other parts of your humidifier. Dip your toothbrush in the reserved bleach solution and scrub all of the nooks and crannies.

4. Rinse and Dry

Thoroughly rinse each part of the humidifier under running water. Continue to do this until the smell of bleach is totally gone. Place all of the disassembled parts on a clean towel and let them air dry. 

Once everything is dry, put the humidifier back together again. Fill the tank with water and you’re good to go!

Tips for Cleaning your Humidifier

Here are some tips to help you clean your humidifier correctly:

  • Clean your humidifier with vinegar every 3 days.
  • Do not mix vinegar with bleach. This can create toxic chlorine gas.
  • Disinfect each part of your humidifier with bleach every 2–4 weeks.
  • Opt for filtered water if you can – it can help reduce mineral buildup.
  • Use a soft dish brush or toothbrush to remove lingering mineral buildup.
  • You can use red wine vinegar if you don’t have any white vinegar on hand. But, most folks opt for white because it doesn’t stain or discolor the unit.


Humidifiers can help keep your home moist in cold or dry seasons. Just be sure to clean your unit often to prevent bacteria or mold growth. These microorganisms can cause flu-like symptoms, and in more severe cases, respiratory infections. 

Source List

Indoor Air Facts No. 8 Use and Care of  Home Humidifiers. (1991). 

Mormim A, et al. (2022). Chlorine Gas Toxicity.

Ono M, et al. (2021). A Case of Humidifier Lung With a Difficult Differential Diagnosis from COVID-19.

Shimoda M, et al. (2018). Humidifier Lung: Characterization of Features and Comparison to Other Hypersensitivity Pneumonitis Phenotypes. 

Use and Care of Home Humidifiers. (2022).