How to Get Rid of Musty Smell from Humidifier

A high-quality humidifier is an asset to have in your home! The device comes in handy with the air dry problem in winter and are meant to add moisture to the air. Health-wise, humidifiers are perfect for those suffering from dry skin and sinuses, and it also lessens the risks of catching a cold or flu by moisturizing the air.  

However, it does not last forever without fixing it at least once or twice throughout its usage. In addition, the humidifier often develops a smell if not cleaned correctly from time to time. So if your device is giving off an unpleasant odor, do not worry!

 This article will discuss how to get rid of the smell and keep the humidifiers clean.

Why do my Humidifier Smell Musty?

Stagnant water and mineral deposits are the root cause of all musty humidifier smell. When water sits in the humidifiers for an extended period, they become stale and provides a good breeding ground for bacteria and odor causing substances. This poses health hazard to those who breathe the water vapor from the unclean humidifier.

Why Your Humidifier Smelling is a Problem

A humidifier is not designed to run all the time, and they are usually turned off when not needed. When the humidifier smells bad, then mold growing inside the stagnant water is the cause and may create the need to clean the humidifier regularly.

The stale water in your humidifier can be problematic if you breathe that air for an extended period. Below are several problems that tag along with humidifier smells. 


A smelling humidifier means an uncomfortable home, and the fishy odor released in the air create a discomforting environment. Additionally, the unpleasant smell can also cause health problems. 


People with respiratory conditions such as asthma and allergies are more prone to these musky smell in humidifiers. The spores that gather inside increase their risk of illness, and worsens the condition if they already have one. 

People with allergies like pollen, dust, and pet fur are sensitive to humidifier smells. If you have such allergies, it is best to turn off the humidifier with unpleasant smell.


The mold growth can cause respiratory problems such as bronchitis, dry skin, sinus infections, and pneumonia. It is crucial to keep the humidifier clean and the reservoir dry when not in use.

Body Aches

Humidifier smells can cause body aches. The air you breathe is filled with stale water, and dust. The spores that gather inside the device spread around when turned on. This causes headaches and fatigue due to a lack of good air quality. 

Reasons for the Musty smells

There are several reasons behind humidifier smells. The most common reasons for this problem are listed below:

Mold and Mildew Build up in the Humidifier

Mold is a fungus that build up on any surface with excess moisture. The humidifier absorbs the water and provides a comfortable environment for mold an dust mites growth. 

This occurs when the humidity inside the humidifier rises past 70%. When you keep the device running for long, it becomes an ideal home for molds and mildew, thus the humidifier smells bad.

Dirty Filters

Filters are a must-have accessory for your humidifier. The humidifier filter keep the distilled water clean and provide moisture to the air. However, it is essential to change or clean them once every few months as they become dirty over time. 

The dirt from filtered impurities from tap water and mineral build up in the reservoir’s surface. Left uncleaned, the mineral deposits can be inhaled leading to severe diseases. If you notice white specks of dust on furniture in the same room as a working humidifier, then the mineral deposits are likely to be the cause of the smell. If you do not regularly replace or clean the filter, mold growth is inevitable. Over time, you might begin to notice the humidifier smells bad.

If the smell persists after changing the filters, then a thorough cleaning is necessary.

Evaporator Belt Failure

The evaporator belt is a rubber band that connects the motor and fan. Over time, this part gets worn out due to use. The fan stops working when the belt wears down, and the humidifier does not work efficiently. 

The humidifier may start to smell musty when the evaporator belt fails, and this is because air does not move through the device, and water starts gathering in different parts of the machine.

Stagnant Water Inside Humidifier

When the evaporator belt fails, it does not turn to rotate the water inside, and this causes stagnant water that gathers into one corner of the humidifier or at places where there is no filter or drain system. 

Additionally, clean water in the reserve tank also stagnates and turns dirty. The stagnant water provides an ideal environment for bacteria growth. This water eventually festers, leading to a pungent smells in your humidifier. Inhallation of the unclean water vapor can posse health complications and make the entire household sick.

Incorrect Humidifier Size for Your Room

It is important to determine which size suits your home before getting one for yourself. The size of your room affects the humidifier that you use. If you choose a large capacity humidifier for a small space, the machine will produce too much humidity inside the room. 

There are two basic size-types of humidifiers, portable humidifiers and whole house.

Excess humidity in the device, in turn, promotes the bacteria growth, and this leads to a pungent smells in the humidifier.

How Do You Get the Musty Smell Out of a Humidifier?

If you notice a humidifier smell, then it means it is time you need to clean the device. Regular maintenance and deep cleaning of the humidifier prevents musty smell from developing inside the humidifier.

 Additionally, it would help if you considered using baking soda to clean it up entirely and prevent any foul odor from sticking around for long.

What to Put in Humidifier to Prevent Mold?

You can put several things into the humidifier to prevent biological growth. These include household items such as;

White Vinegar; It is an excellent mold-breaker and prevents any biological growth in your humidifier. Add one cup of vinegar or cleaning agent to the water inside the water tank, and run it for an hour. 

Tea Tree Oil; Tea tree oil is another compelling element that prevents biological. Add a few drops of tea tree oil to the clean water in your humidifier and leave it overnight. It can also aid in breathing for those suffering from asthma, cold, and flu.

Hydrogen Peroxide; This is another powerful antibacterial element that can prevent mildew formation inside the humidifier. Add half a teaspoon of hydrogen peroxide to the distilled water inside your humidifier and leave it on overnight. Hydrogen peroxide is inexpensive and has an enzyme property that aid in removing the urine smell.

Essential Oils; Essential oils like lavender, eucalyptus oil, peppermint oil, and lemongrass are antibacterial elements that prevent the growth of bacteria in your humidifier. Add a few drops of essential oils to the water tank and run your humidifier for a few hours. These essential oils have antibacterial, antiviral and antimicrobial features. Essential oils are natural and healthy and have a fresh smell.

Humidifier tablets; The tablets are found in your local supermarket or grocery store. They are specially made to prevent biological growth in humidifiers when added to distilled water during cleaning cycles.

Can Mold in a Humidifier Make you Sick?

Yes, mold in a humidifier can spread and cause health complications the need for a mold free humidifier. This is because particles float around in the air when the humidifier is on. They are not healthy for humans because it can cause allergies or respiratory problems such as asthma attacks. 

When inhaled, it can lead to respiratory infections like pneumonia, cold, or flu. Other effects include headaches, fatigue, coughing, and wheezing.

How Do I Know If My Humidifier Has Mold?

Telling if your humidifier has biological growth is not easy. However, you might check out for the following signs;

  • You may start noticing a slight musty smell after some time. 
  • You might notice a slight discoloration of the water in your humidifier. This happens at the initial stages of growth and spread. 
  • Discoloration on the water tank or parts of your humidifier is another sign that you need to look at. You will see black spots or patches on the water tank walls.
  • Check the humidifier filter of the device. If the filters are covered with black or brown spots, it can indicate that mold has started to develop inside your humidifier.
  • You should also check if there is any debris inside it, as this can be a possible indication that you have molds in your humidifier.
  • White specks of dust

How Often Should Humidifiers Be Cleaned?

Regular cleaning of the humidifier is necessary to prevent the growth of fungi and mildew. It would help if you cleaned the device weekly or after every two weeks depending on how much you use it and where you place it in your house. 

This will help ensure that all the dirt, debris, and other substances do not settle inside the device’s water tank. Additionally, this will prevent the odor causing bacteria from developing inside it.

How to Clean a Humidifier with Mold

Cleaning your humidifier is an essential part of its maintenance. If the humidifier is not cleaned properly, it can spread bacteria. In addition, cleaning weekly might be recommended for people who suffer from allergies and other respiratory conditions. 

On average, cleaning requires around 30 minutes. However, before kicking off the washing process, it is best to read the user manual that came with the device. 

You will also require the following materials for the process:

  • Distilled white vinegar or baking soda,
  • Liquid chlorine bleach,
  • Cleaning cloth/soft toothbrush. 

Follow the below steps to clean your humidifier:

Step 1. Unplug and empty water

Unplug all electrical wires connected to the device before starting the cleaning process. Next, open up all humidifier parts, including filters, evaporator belt, fan cover, and other accessories.

You can soak each part in hot water and add bleach to kill any bacteria 

Please turn off the water supply and empty any remaining water present in it. You can use a towel or sponge and hot water for this purpose, depending on the size of your humidifier.

Step 2. Clean the base and the tank

Add a cup of chlorine bleach to the water in a container, then add vinegar or baking soda into it. Mix thoroughly until both liquid contents dissolve well in the water. Pour the mixture into the water tank of your humidifier and leave it for 10-15 minutes.

This will allow the cleaning solution to work through the water tank and base and loosen stiff stains. Swish it around to clean the inside of the tank and empty it.

Step 3. Clean other parts of the humidifier

You will need to clean other humidifier parts with a cleaning cloth or toothbrush. Please get rid of any dirt, dust, and the biological growth accumulated over time. 

Dip the cloth in a vinegar solution, wipe down the fan blades, evaporator belt, and other accessories. Scrub each part thoroughly, rinse them in warm water, and air dry before placing them back into the device. 

Step 4. Reassemble back the humidifier

Reassemble back the parts of your device after they are completely dry. Next, plug in all electrical wires, turn on the water supply, and fill the humidifier tank with clean distilled water. Use either treated or distilled water, hard water leaves behind mineral residue. The mineral residue later start smelling like urine due to chlorine and lead. Demineralized water has no mineral content. Inspect the power cord and ensure there is no burning at the outlet. When there is a problem with power in specific outlet, plug the humidifier in outlet in a different circuit and see if you get the same burning smell.

Step 5. Turn on the humidifier and check for leaks

Please turn on your device, then place it in its desired use location. Check for leakages or spills around the unit’s base while running to ensure that all parts are correctly sealed together again. 


Humidifiers are a great way to help you overcome a dry skin during winter. However, these devices can become breeding grounds for bacteria and mold if not cleaned regularly with the proper cleaning methods.

It is best to clean your humidifier weekly or after every two weeks depending upon usage levels, to prevent any of this from developing inside it. Additionally, maintaining the device will prevent any musty odor from developing inside it.

Cleaning the humidifier with mold is not very difficult. With the right cleaning supplies, you can quickly disinfect and clean your device every few days, depending upon the frequency of usage. You can follow the above steps to clean it.