Cleaning a Cool Mist Humidifier

By: Evan Scoboria, Last updated: June 28, 2023

Taking proper care of your cool mist humidifier is crucial for its longevity and the health and well-being of those in your household. Regularly cleaning your humidifier can prevent the growth of mold and bacteria that might otherwise disperse into the air. This article provides a comprehensive guide to cleaning your cool mist humidifier, outlining the materials needed, a detailed step-by-step process, and some helpful tips.

Cleaning a Cool Mist Humidifier

The Need for Cleaning Cool Mist Humidifiers

Like any other home appliance, cool mist humidifiers require regular maintenance to function at their best. These devices work by dispersing a cool, soothing mist into the room to maintain optimal humidity levels. However, mineral deposits can form over time, and bacteria or mold may grow inside the humidifier if not cleaned regularly.

Unclean humidifiers can disperse these unwanted substances into the air, which you and your loved ones might inhale. This can lead to potential health issues such as allergies, asthma flare-ups, or lung infections. Furthermore, the type of water used in the device, particularly hard water, can accelerate mineral deposit build-up, thus requiring more frequent cleaning.

Gather Your Cleaning Supplies

Before starting, ensure you have the necessary cleaning supplies. These include:

  1. White vinegar is a natural descaler that will help remove mineral deposits.
  2. Hydrogen peroxide: A safe disinfectant that can kill bacteria or mold.
  3. Soft brush: This will help you scrub away residue and reach tricky areas.
  4. Clean cloth: For wiping down and drying components.
  5. Fresh water: To rinse off the cleaning solutions.

Natural cleaners like vinegar and hydrogen peroxide ensure a safe cleaning process, which is essential for devices like humidifiers that directly impact air quality.

Step-by-step Guide to Cleaning a Cool Mist Humidifier

Pre-cleaning steps

Before you begin the cleaning process on your cool mist humidifier, there are some preparatory steps you should take:

  1. Unplug the humidifier: The first and most crucial step is to unplug the humidifier from the power source. This is a safety measure to prevent any electrical accidents.

  2. Empty the water tank: Remove the water tank from the humidifier base, if possible, and empty any remaining water. Discard the water down a sink or outside.

  3. Disassemble the humidifier: Depending on your model, this may involve removing the tank, nozzle, or filter. Check your user manual to ensure you're disassembling it correctly.

  4. Prepare your cleaning area: Clean an ample space on your counter or table where you can lay out all of the parts of the humidifier. This will help you keep track of all parts and make cleaning easier.

  5. Put on gloves: This step is optional, but to protect your skin from any grime or potential mold, it's a good idea to wear rubber or disposable gloves.

Remember, every humidifier is slightly different, so refer to your device's user manual for specific instructions. Preparing correctly makes the cleaning process smoother and more effective.

Cleaning the water tank

Cleaning the water tank of your cool mist humidifier is crucial in maintaining a healthy and hygienic device. Here's a step-by-step guide to help you clean it efficiently:

  1. Create a cleaning solution: Fill the tank halfway with warm water and add two tablespoons of white vinegar. This natural, non-toxic cleaner helps break down any mineral deposits or mold in the tank. If your tank has significant build-up, you may want to increase vinegar.

  2. Shake well: Secure the cap back onto your tank and shake it vigorously. The goal is to allow the vinegar-water mixture to reach all the areas inside the tank.

  3. Soak: Let the vinegar-water mixture sit in the tank for at least 20-30 minutes, or longer if needed, depending on the level of build-up.

  4. Scrub: Use a brush or sponge to scrub inside the tank after soaking. Specific brushes are designed for cleaning humidifier tanks, which can be particularly useful for reaching awkward spaces.

  5. Rinse thoroughly: Rinse the tank thoroughly with warm water to ensure no vinegar residue is left inside. It may require several rinses to remove the vinegar smell entirely.

  6. Dry: Let the tank air dry before reassembling and using your humidifier. Ensure it's completely dry to prevent any new bacteria or mold from forming.

Remember to never use bleach or other harsh chemicals for cleaning as they could harm the humidifier and potentially release harmful chemicals into the air when the humidifier is in use. Always refer to your user manual for specific cleaning instructions.

Cleaning other parts of the humidifier

Cleaning other parts of your cool mist humidifier is also essential for optimal performance and hygiene. Let's take a look at how you can clean the base, clean the wick filter (if your humidifier has one), and clean the exterior:

Cleaning the Base:

  1. Unplug and empty: Unplug the humidifier from the power source, and if there is any water left in the base, empty it.

  2. Prepare cleaning solution: Fill the base with equal parts white vinegar and warm water. Alternatively, you can use a gentle cleaning solution provided by the manufacturer.

  3. Soak and scrub: Let the solution sit for around 20 minutes to loosen any mineral deposits. After soaking, clean the base with a soft brush or cloth.

  4. Rinse and dry: Rinse the base thoroughly with warm water, ensuring all vinegar or cleaning solution is removed. Allow it to dry completely before reassembling.

Cleaning the Wick Filter:

  1. Remove the filter: Most cool mist humidifiers use a wick filter. Refer to your user manual to safely remove it.

  2. Soak the filter: Soak the filter in a vinegar-water solution for about 20 minutes.

  3. Rinse the filter: Rinse the filter under cool running water. Do not wring or squeeze the filter, as it may damage it.

  4. Dry the filter: Allow the filter to dry completely before reassembling. Replace the filter per the manufacturer's guidelines or if it appears discolored, damaged, or moldy.

Cleaning the Exterior:

  1. Wipe down: Wipe down the exterior of the humidifier with a damp cloth and mild detergent.

  2. Dry: Allow the exterior to dry thoroughly before plugging in and using the humidifier.

Maintaining your humidifier by cleaning these parts regularly helps prolong the life of the device and ensures it's safe to use in your home. Always follow the manufacturer's instructions for the best care practices.

Drying and reassembling the humidifier

Once all the parts of your cool mist humidifier have been thoroughly cleaned, it's essential to let them dry before reassembling the unit. Here are the steps for that final phase:


  1. Air Dry: Let all the components air dry completely. This process can be expedited by placing them on a clean, absorbent towel in a well-ventilated area. It's crucial to ensure that all parts are dry to prevent mold and bacteria growth.

  2. Do Not Rush: Resist the urge to speed up the drying process with a hairdryer or by placing the parts near a heating vent. The high heat could warp or damage the components. Patience is key here!


Once everything is completely dry, you can start putting your humidifier back together.

  1. Follow the manual: It's usually best to refer to your humidifier’s user manual for specific instructions on reassembling the unit. This ensures that you won't accidentally damage any parts during this process.

  2. Reinstall the wick filter: If your humidifier uses a wick filter, carefully reinstall it. Ensure it fits properly and is not bent or crumpled.

  3. Reattach the tank to the base: Once the base is dry, you can reattach the tank. Make sure it fits securely, and there are no leaks.

  4. Plug in and test: After reassembling, fill the tank with fresh water, plug in the unit, and test to ensure it works properly.

Regularly cleaning and properly maintaining your cool mist humidifier can significantly extend its lifespan and effectiveness.

How Often Should You Clean a Cool Mist Humidifier?

The frequency of cleaning your cool mist humidifier can depend on several factors, including how often you use it and the type of water you use. However, as a general rule, it's advisable to thoroughly clean your cool mist humidifier every one to two weeks.

If you're using your humidifier daily, it's a good practice to rinse the water tank every day and refill it with fresh water. Also, if you're using hard water, which can leave more mineral deposits, you might need to clean your humidifier more often.

Additionally, you should always look for any signs of mold or mineral buildup in your humidifier. If you notice any such symptoms, it's time for a cleaning, regardless of when the last cleaning occurred. Regular cleaning will help your humidifier perform better and ensure the mist it emits is safe for you and your family.

Troubleshooting Common Problems

When it comes to cool mist humidifiers, certain issues can pop up from time to time. Here are a few common problems and how you can troubleshoot them:

  1. Humidifier isn’t producing mist: This could be due to a lack of water, a blocked filter, or a broken fan. Ensure the tank is filled with clean water, check if the filter needs cleaning or replacement, and verify that the fan is functioning correctly.

  2. Unusual noise from the humidifier: Most often, this is due to a build-up of scale on the transducer plate. Regular cleaning can prevent this issue. If the noise persists even after cleaning, the fan might be faulty, and you may need professional assistance.

  3. Humidifier is leaking: This could be because of a cracked or improperly positioned tank. Check the tank for any damage and ensure that it is placed correctly. If the tank is damaged, you will need to replace it.

  4. The humidifier produces an unpleasant smell: This is usually a sign of bacterial or mold growth. If you notice an unpleasant odor, cleaning your humidifier thoroughly using the steps in this guide is crucial.

Remember, if you consistently encounter issues that you cannot resolve yourself, it's best to contact the manufacturer's customer service for further assistance. A humidifier should be a tool for enhancing your comfort, not causing distress!


Maintaining a clean, cool mist humidifier is an essential yet straightforward task. Regular cleaning ensures your device functions optimally, extends its lifespan, and, more importantly, keeps your indoor air clean and safe.

Frequently Asked Questions

  1. Can I use bleach to clean my humidifier? It's not recommended due to its harshness and potential to leave residues that might disperse into the air.
  2. How do I clean a humidifier with mold in it? Use a solution of one part hydrogen peroxide to ten parts water to kill the mold.
  3. Is it safe to run a dirty humidifier? No, it could disperse harmful particles into the air.
  4. Can a dirty humidifier make you sick? Yes, bacteria or mold in a dirty humidifier can lead to respiratory issues.
  5. Is distilled water better for my humidifier? Yes, distilled water has fewer minerals and can reduce the frequency of cleaning.