All The Reasons Why Your Diffuser Is Not Working

A diffuser is not working properly if it is not misting or emitting smell, spits water or keeps turning off. An incorrect water level, poor positioning, mineral build-up, cold water, or power cord issues are the most common causes of a diffuser not working. A broken fan, water in the electronic components or dirt deposits can also cause a diffuser to malfunction.

More than a third of all Americans believe in the health advantages of essential oil diffusers, with many using essential oils for aromatherapy as a supplemental or alternative therapy. However, diffuses can often stop working, which can be extremely frustrating.

This guide will take you through the different types of diffusers, and give you all the possible reasons why your diffuser is not working, including solutions.

Types of diffusers that can stop working

There are several different types of diffusers and some of the reasons why a diffuser can stop working only apply to a specific type of diffuser. If you aren’t sure which diffuser you have check out the description below then jump to the reasons why your diffuser has stopped working.

1. Nebulizing diffusers

The Nebulizing diffuser is an essential oil diffuser that works by breaking down the oil into smaller molecules that can be spread and absorbed more easily. Unlike the other diffusers, this type of diffuser does not use water but instead uses only essential oils.

The fine mist produced by the nebulizing diffuser does not affect the chemical makeup or aroma of the oil, and it diffuses it all at once rather than in stages. The particles are tiny enough to be inhaled readily and utilized for aromatherapy.

It is the most effective essential oil diffuser, but it is quite expensive to acquire and use compared to other diffusers.

2. Ultrasonic diffusers

An ultrasonic diffuser is a type of diffuser that creates a fine mist from essential oils and water using water and electronic frequencies. A little disk under the water’s surface generates ultrasonic vibrations, which force the essential oil to split up into tiny micro particles.

When you add essential oils to water, the vibration breaks the essential oil down into small particles, which are then misted into the air.

Ultrasonic diffusers are the most popular diffusers and very affordable to use because they use a large amount of water with only a few drops of essential oils.

3. Heat diffusers

A heat diffuser is a diffuser that uses heat elements to aid in the gradual evaporation of essential oils into the air. Heat essential oil diffusers are sometimes used with the oil mixed with water.

Some heat diffusers utilize a lot of heat to create a greater aroma, while others use a little heat to keep the chemical contents of the oils from deteriorating too much.

4. Evaporative diffusers

Evaporative diffusers are diffusers that use evaporative dispersion and air flow to disperse the aroma of essential oils throughout the room with a fan that circulates air through a filter, such as a tissue or a pad soaked in essential oils. The oil soon evaporates due to the flowing air, and the air containing the evaporated oil is blasted into and around the room.

All the reasons why a diffuser may not be working

There are various reasons why a diffuser may not work. These may occur from the diffuser itself not turning on, issues with its misting, power cord issues, or issues with scent emission.

What it means by the” diffuser not working?”

A diffuser that is not working could be the one with the following issues:

  • Not misting.
  • Keeps turning off.
  • Spits water.
  • Does not emit smell.
  • Not turning on.

Not misting

A diffuser that is ‘not misting’ is one that has powered on, but it is not producing any mist whatsoever. Alternatively, a diffuser that is misting but not as strongly as it should – this is particularly common with ultrasonic diffusers.

Reasons for a diffuser not misting:

1. The water level

The water level can affect the misting of your ultrasonic essential oil diffuser. Before turning on the diffuser, make sure the water level is correct. The mist will not be sufficiently strong if there is too much water. To achieve a powerful misting, fill the water slightly below the maximum fill line.

The ultrasonic plate will have to work harder to get the mist to come out if there is too much water. On the other hand, if there isn’t enough water, the mechanism may stop working altogether.

Diagnostic features:

  • If the diffuser is making a loud noise.


  • Fill the container with water just below the maximum fill line.
  • Make sure the bowl is full of water and that the water level is correct.
  • If you’re not sure what to do, consult your user handbook.
  • To avoid water getting into other compartments, don’t move the diffuser around when it’s full.
  • Make sure you use only filtered water, tap water, or spring water. If you use distilled water, the diffusion will be affected.

2. Bad positioning

The amount of misting you get from your diffuser is also determined by where you place it. Do not place it on something soft, such as a towel that will not absorb the ultrasonic vibrations, as this will disrupt the misting. 

Running the diffuser over soft surfaces like towels, mats, or carpet may block airflow, could cause spills, or cause the unit to tip over accidentally.

Diagnostic features:

  • Loud noise due to uneven surface.


  • Use a diffuser on any level and hard surface.
  • Check that the lid is secure and that it is seated properly on the unit’s base.

3. Location

The misting of a diffuser is entirely dependent on its position. Make sure the device isn’t directly beneath an air vent or fan that could be causing the mist to disperse. Positioning a diffuser just below the AC can cause the diffuser’s mist not to be noticed.

Diagnostic features:

  • The diffuser is misting but the mist doesn’t last to disperse a room.


  • Place it away from the AC or a fan.
  • If you are not sure where to place your diffuser, consult the user manual.

4. Mineral build-up

The amount of mist produced by a diffuser is also determined by its cleanliness. The unit may have trouble misting if the diffuser is unclean or has mineral or oil deposits built up inside.

Diagnostic features:

  • White substances in the diffuser.
  • Presence of scale.


  • Cleaning it after every use.
  • Unclogging the diffuser and removing any scale/limescale deposits (warm water and soap should be sufficient, but vinegar can also be used where necessary).
  • Scheduling a regular cleaning routine.

If you have a buildup of black stuff in your diffuser, Plentiful Air has detailed information on how to remove and prevent it available here.

5. Water temperature

The misting of a diffuser can also be affected by the temperature of the water. Because of a change in density, the temperature of the water can impact how much mist is generated by the diffuser.

Greater density means that vibrating the cold water to excite the molecules sufficiently to lift them into the air would cost more energy. On the other hand, Warm water has a lower density, which allows its molecules to bounce further apart and rise above cooler water. As a result, heated water produced more mist in a diffuser.


  • For greater misting, use warm water.

6. Water mineral content

The mineral content of the water has an impact on diffusion and misting because the ultrasonic plate vibrates the water molecules using the minerals. Because the ultrasonic disc can vibrate more effectively, water with a higher mineral concentration usually produces more vapor.

Different sorts of water are required for different diffusers to function properly. Certain diffusers advocate using distilled water to prevent mineral deposits from forming on the ultrasonic disc. 

Although most diffusers recommend using only filtered, tap, or spring water.

Diagnostic features:

  • Water with minerals will form a white scale on the diffuser’s reservoir.


  • Consult the user manual.
  • Use only the water recommended by the user manual in the diffuser.

7. Broken fan

The fan could be the issue if you can’t hear it operating and there’s no mist coming out.

An oil diffuser has several moving and important components, but the fan is what propels the water mist out of the diffuser and throughout your home.

The fan in your oil diffuser is definitely faulty if it still turns on but can’t spread the water vapor it creates. The fan’s primary function is to force the mist out of the compartment; if it fails to do so, the mist will remain inside.

Diagnostic features:

  • Loud noise coming from the diffuser.


  • Check if any dried up oil essential oil has clogged the fan inlet. If there is any dirt remaining on your diffuser, clean it.
  • Try blowing into the fan or directing puffs of air into the entrance using an empty squeeze bottle if you suspect a clogged air vent.
  • Contact your manufacturer if the device is still under warranty.
  • Purchase a new diffuser.

Keeps turning off

A diffuser that keeps turning off is one that powers on but cannot stay on and instead keeps turning off after a moment, making it difficult to diffuse a room. It applies to both ultrasonic and nebulizing diffusers.

Reasons for a diffuser turning off:

1. Contamination

If water or essential oil comes into touch with the electrical components of your essential oil diffuser, it will immediately stop working. If it does not completely stop working, it may begin to shut down more frequently, preventing it from adequately diffusing a room.

When you lay your diffuser on an uneven surface, remove the lid while the diffuser is operating or if something inside the diffuser breaks and allows water out, water enters into the electrical components. Water can also enter the electrical components if you overfill the water and it spits out of its reservoir.

The air vent is the most likely way for water to enter your diffuser. This can be seen on all ultrasonic diffusers, with some indicating that they should not be used near water.

Diagnostic features:

  • If your diffuser turns off again and again.


  • Take it apart and examine for dampness on the electrical components or pooling in the diffuser’s bottom.
  • If water gets into the circuit board or the fan, unplug the machine, remove any water, clean it and let it dry before using it again. 
  • Allow the diffuser to dry completely by placing it upside down on a towel overnight.
  • Do not operate your diffuser without the lid on.
  • Place your diffuser on an even levelled surface.
  • When using an ultrasonic diffuser, use the amount of water directed by the user manual.

Spitting water

A diffuser that is ‘spitting water’ is one that turns on, diffuses a room but keeps spitting water during diffusion. This is common with ultrasonic and heat diffusers because they work with water and essential oils.

Reasons for a diffuser spitting water:

1. Essential oil or mineral build-up

Mineral or oil build-up in your diffuser is the most likely reason why your diffuser is spitting water while dispersing air. This comes about if you do not clean your diffuser often.

When essential oils build up on the disk, your diffuser will stop working properly or stop working entirely. If your oil diffuser becomes clogged, it will no longer function properly. Your diffuser will eventually stop working, and you will no longer be able to enjoy essential oils dispersed in the air.

Diagnostic features:

  • If there is a whitish substance or grime in the diffuser’s reservoir.


  • Clean your diffuser after each use.
  • Schedule a regular thorough cleaning routine of your diffuser.

2. Cold water

Another reason your diffuser may spit water could be because the water you are using is too cold, hence spitting water instead of mist.

Diagnostic features:

  • Diffuser spitting water.


  • Use warm or lukewarm water instead of cold water.

3. Uncovered diffuser

Your diffuser could also spit water if you use it without covering it with its lid. The lid is meant to help with avoiding it to spit water while dispersing a room.


  • Ensure that the tank lid is in place and that all of the diffuser components are in place.

Not emitting smell

A diffuser could turn on, but the user or anyone present at home does not really perceive its scent. That does not necessarily mean that your diffuser is malfunctioning. It could be because of other factors such as the quality of the essential oils, the quantity of essential oil, a dirty diffuser, or its CADR (or area coverage per square meter).

If you can’t smell the aroma, it’s possible that you chose a diffuser that is too small for your space, the essential oil or blends you are using is too diluted or the essential oil is of poor quality. Other reasons include a dirty diffuser or the device being on low misting mode. It applies to all diffusers; ultrasonic, nebulizing, heat, and evaporative diffusers.

Diagnostic features of a diffuser that doesn’t emit smell:

  • Your diffuser is on, but you don’t perceive any smell.
  • The diffuser is misting but with no scent.

Reasons why your diffuser is not emitting smell:

1. Quality of essential oil

Issues with your diffuser not emitting smell typically arise because of the quality of the essential oil you are using in the diffuser. If you use a low quality essential oil in your diffuser, then it’s probably not able to adequately emit the scent that you need.

You should constantly examine the ingredients list when purchasing essential oils. Essential oils can be expensive, which is why many companies go online and sell less expensive essential oils that may be of poor quality. So be cautious when buying yours, in particular ensure they are not diluted.

Diagnostic features of a low quality essential oil:

  • If the bottle isn’t made of glass, dark and firmly sealed.
  • If you have used it as directed by the user manual but there is still no smell coming out.


  • Check the ingredient list before purchasing your essential oil.
  • Make sure the essential oils you’re utilizing are 100 percent pure.
  • Do not buy cheap essential oils.
  • Buy your essential oils from a trusted source.

2. Quantity of essential oil

The quantity of the essential oils that you use in your diffuser also matters a lot. For instance, if you are using a 1000ml diffuser and you only use 2 drops of your favorite essential oil, you will not be able to perceive any scent.

Essential oil dilution is a key step in dispersing a home or office. While it’s crucial to avoid using too much essential oil in your diffuser, you should also avoid using too little.

The user manual clearly recommends how many drops of the essential oil you are supposed to use in your diffuser to adequately diffuse your home.


  • Consulting the user manual.
  • Using enough essential oils.

3. Size of the room

Are you diffusing in a larger room? If yes, how many diffusers do you have? Every diffuser has its area coverage or CADR rating. If you are using just one diffuser to diffuse a larger room, you might not be able to perceive any smell coming out of your diffuser. 

When it comes to choosing a good diffuser to diffuse a larger room, it becomes a little complicated. But do not worry because this guide has you covered, 20 Best Diffusers For Large Rooms.

Diagnostic features:

  • You are using quality essential oils, enough and as directed by the user manual but still, there is no smell.


  • Buying two or more diffusers if your room is larger.
  • Investing in high quality essential oils.
  • Placing your diffusers strategically, i.e., in the middle of the room.
  • Using a good quantity of essential oils.
  • Investing in good air purifiers for larger rooms covered in our previous post.

4. Misting level

Diffusers are made up of a variety of components, and most types have high and low mist settings. Because your diffuser is on low mist mode and diffusing a broader area, it may appear that it is not generating any scent.

A diffuser should ideally feature a heavy (or high) mist setting to get more mist in the air. The majority of diffusers have a strong mist setting. Setting your diffuser to heavy mist mode will ensure the best possible scent and coverage.


  • Set your diffuser on high mist mode.

5. Dirty diffuser

It’s also possible that your diffuser isn’t releasing any scent since it’s dirty. Mineral build-up or even mold growth can prevent a dirty diffuser from emitting any smells, which is why it is recommended to clean a diffuser after every use.


  • Cleaning your diffuser after each use.
  • Scheduling a regular cleaning routine.
  • Do not leave water sitting in your diffuser’s reservoir.
  • After cleaning it, leave it to completely dry before using it again.

Not turning on

A diffuser that is “not turning on” is one that is not doing anything whatsoever. That means that it does not power on, mist, or even emit any smell. This applies to all kinds of diffusers, i.e., ultrasonic, evaporative, heat, and nebulizing diffusers.

Reasons for a diffuser not turning on:

1. Power cord issues

One of the most common reasons why your oil diffuser isn’t working properly is that the power source it relies on isn’t working. Most diffusers will not work if the power cord is damaged. Most electric oil diffusers, for example, must be plugged into a power source, such as a wall outlet in your home.

Like any other home appliance, a diffuser will not work or turn on if it has a power cord or electrical issues.

Diagnostic features:

  • When a diffuser does not power on at all.


  • Try plugging your diffuser into a separate outlet in your house.
  • Try plugging in another electric item, such as a kitchen appliance, to see whether it works.
  • Test whether your power supply is at fault by plugging a different appliance rather than your diffuser to check that the unit is receiving enough power.
  • Replace your plug or outlet depending on the primary issue.

2. Not plugged in.

Another easy but typical reason for your diffuser not working is that you haven’t plugged it in, or if you have, you haven’t plugged it in correctly.

A diffuser for essential oils usually includes two plugs. One is where the power cord connects to the power source, and the other is where the cable connects to the diffuser itself. If your diffuser has plugs, make sure they’re connected in and working correctly.


  • Check if you have plugged the diffuser.
  • Ensuring it is correctly plugged in.
  • Ensure that you are using the correct power adaptor.
  • Make sure the power adapter is firmly seated in the wall outlet.
  • Ensure the power source is securely plugged into the diffuser’s back socket.

How to unclog a diffuser

To unclog a diffuser, disconnect the diffuser from the source of power, remove any remaining water or essential oils, fill the diffuser tank with clean water. Allow the diffuser to run for a few minutes, and then empty the diffuser tank.

For a deeper clean, there are two primary alternatives to choose from when cleaning your essential oil diffuser with everyday household items made from natural ingredients. They include:

  1. White vinegar.
  2. Rubbing alcohol.

With White vinegar:

  • Unplug your diffuser from the source of power.
  • Empty any water that is in the diffuser.
  • Fill your diffuser about half way with clean water.
  • Add up to ten drops of pure white vinegar to the mixture. This will aid in removing oils stuck inside the diffuser and on the glass or plastic parts.
  • Allow the water-vinegar mixture to disperse throughout the device and clean it by running the diffuser for around 10 minutes.
  • Completely drain the diffuser.
  • Clean the tight parts and corners of the diffuser with a cotton swab coated in vinegar to ensure that no spots are left filthy.
  • Rinse well with fresh water.
  • Wipe the diffuser down with a dry towel, cotton swabs, or cotton balls, and let it dry completely.
  • Wipe off the exterior of the appliance using a damp cloth.
  • Reassemble it and use it.

With Rubbing alcohol:

  • Unplug your diffuser from the source of power.
  • Empty your old water from the diffuser’s reservoir down the sink.
  • Fill your diffuser with rubbing alcohol.
  • Let your diffuser sit overnight. 
  • Empty the rubbing alcohol from the diffuser’s reservoir.
  • Using a gentle cloth, clean the inside of the diffuser.
  • After that, clean the ultrasonic plate with a cotton swab dipped in rubbing alcohol to remove any build-up, oily residue, and clean any hard-to-reach locations in your diffuser.
  • Wipe it down with a dry cloth after rinsing it with clean water.
  • Allow it to dry before using it again.

Note: Always consult your user manual if you are not sure what to do.

How often and when you should clean your diffuser

An essential oil diffuser should be cleaned after every use. This is due to the essential oils used in it, as they can create deposits and clog the diffuser over time. It is also important if you intend to change essential oils. If you can’t wash it after each use, simply drain the remaining water in the reservoir, rinse it with clean water and dry it.

However, if you intend to extend the life of your diffuser and enjoy quality misting in your home, schedule a regular cleaning routine. Rinsing after each use, washing it at least twice a week or 4 times monthly.

If you don’t clean it as required, the diffuser can grow molds that are harmful to human health due to moist environments. Additionally, your diffuser could be damaged.

How long does it take for a diffuser to start misting?

If everything is set up correctly, a diffuser should start misting after 2 to 5 minutes. Ensure you follow the recommendations on the user manual on how to use it and use the right type and amount of water, quality essential oils for effective misting.

Theresa Orr

Theresa Orr holds a PhD in Earth Science and specializes in determining past climates from rocks using geochemistry. Her passion for clean water, soil and air drives her to provide easy to understand information for everyone to read.

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