All The Reasons Why Your Humidifier Is Not Working


Humidifiers are useful devices that provide moisture to the air and help prevent dry skin, nose, throat, and lips. However, from time to time a humidifier can stop working for various reasons, and will need some repair or maintenance.

A humidifier is not working properly if it’s not switching on, misting, staying on, or is leaking, gurgling or making excessive noise. Power cord issues, mineral deposits, water level, location, and position are the most common causes of a humidifier not working. Other reasons include contamination, a faulty humidistat or a broken fan.

This guide will walk you through the different types of humidifiers, and provide all of the possible reasons why a humidifier isn’t working by highlighting diagnostic features and step-by-step solutions for each problem, including the following types of humidifiers.

Different types of humidifiers

There are various types of humidifiers. Each humidifier uses different techniques to humidify the room. They include;

1. Cool mist humidifiers

Cool mist humidifiers use a filter to catch water pollutants while emitting a cool vapor mist into the air. They are considered the easiest to clean.

2. Warm mist humidifiers

The water in these humidifiers is heated in order to create vapor. After that, the vapor is cooled before being discharged into the atmosphere.

They have a higher moisture saturation level and are quieter but are more difficult to clean due to frequent mineral deposits.

3. Ultrasonic humidifiers

Ultrasonic humidifiers generate water droplets by vibrating a metal diaphragm at an ultrasonic frequency, which is subsequently blown into the air by a fan.

It comes in two forms, warm and cool ultrasonic humidifiers that you may choose from. These are the quietest humidifiers.

4. Evaporative humidifiers

Because it does not heat water to create humidity, an evaporative humidifier works similarly to a cool mist evaporator. It is a wick humidifier that employs a fan to circulate humidity as water evaporates into a vapor and is released as a spray or mist.

Evaporative humidifiers require low maintenance, are self-regulating, portable, and cost-effective.

5. Vaporizers

Vaporizers are humidifiers that, when set to warm, they send visible steam into the air, and when set to cool, they generate a mist because they combine all of these benefits into one system.

These types of humidifiers are harder to clean and use a lot of energy.

What a “humidifier not working” really means

There are various reasons why a humidifier may stop working. These may occur from the humidifier itself not turning on, issues with spitting water, power cord issues, or issues with increasing humidity.

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

  • Not switching on.
  • Not misting
  • Not staying on
  • Leaking
  • Spitting
  • Making excessive noise
  • Gurgling.
  • Not increasing humidity
  • Not using water.
  • Not blowing air.

Now that we know the different types of humidifiers and what it means by a humidifier not working, here are the different reasons why a humidifier could stop working and which humidifier type each explanation relates to.

Humidifier not misting

A humidifier that is “not misting” is one that has been turned on but doesn’t produce any mist.

Alternatively, a humidifier that is misting but not as much as it should – this is especially common with an ultrasonic humidifier, vaporizers, cool mist, warm mist, and evaporative humidifiers.

Reasons for a humidifier not misting:

1. Mineral deposits

One common reason for a humidifier not making mist is mineral deposits, which can quickly clog up the entire system.

Mineral deposits are caused, or formed by mineral content in the water you use in your humidifier. This is why most manufacturers recommend cleaning your system on a regular basis and using distilled water in it.

Using tap water, especially if you live in a hard water area, can lead to mineral build-up in the humidifier, preventing it from producing mist.

Diagnostic features for mineral deposits:

  • Presence of scale build-up.
  • Whitish or brown substances in the humidifier.

Solutions:

  • Using distilled water or water that the user handbook recommends.
  • Cleaning it by rinsing it with clean water after every use.
  • Unclogging the humidifier and removing any scale/limescale deposits (warm water and soap should be sufficient, but lemon and vinegar can also be used where necessary).
  • Scheduling a regular cleaning routine.

2. Level of water.

The misting of your humidifier is directly affected by the water level. Most humidifiers display a maximum line mark on the water tank/reservoir.

Make sure the water level in the humidifier is correct before turning it on.

There shouldn’t be too much or too little water in the humidifier – a humidifier will not function properly if water passes the max line.

If there is too much water, the mist will not be powerful enough. Fill the water slightly below the maximum fill line to generate a forceful misting. If there is too much water, any ultrasonic plate will have to work harder to get the mist to come out.

On the other hand, if there isn’t enough water, the mechanism can stop working altogether.

Diagnostic features.

  • Loud noises as the humidifier work.

Solutions.

  • Fill the container with water just below the maximum fill line.
  • Make sure the water container/reservoir is full of water and that the water level is correct.
  • If you’re not sure what to do, consult your user handbook.
  • When the humidifier is full, don’t move it around to avoid water getting into other compartments.
  • Make sure you’re just using distilled, filtered, tap, or spring water. The misting may be impaired if you use tap or hard water.

3. Water mineral content.

Water mineral content could also lead to a humidifier not misting. This is common with ultrasonic humidifiers. Because the ultrasonic plate vibrates the water molecules utilizing the minerals, the mineral content of the water has an effect on diffusion and misting.

Water with a higher mineral concentration produces more vapor because the ultrasonic disc can vibrate more effectively.

Different humidifiers require different types of water to function correctly.

To prevent mineral deposits from accumulating on the ultrasonic disc, several manufacturers recommend using distilled water in the humidifier. Although some humidifiers recommend only using filtered, tap, or spring water. As a result, always refer to the user manual.

Diagnostic features.

  • High mineral content water forms white or brown descale in the humidifier.

Solutions.

  • Use distilled, filtered, or water recommended by the manufacturer.
  • Cleaning the humidifier more regularly.

4. Loose or damaged fan

One reason why your humidifier is not misting is a loose or damaged fan.

The water mist from most types of humidifier is dispersed around the home by the fan.

If the humidifier’s fan still turns on but doesn’t disseminate the water vapor it produces, it’s obviously broken. If the fan does not freely turn when pushed then it may just be loose.

Diagnostic features:

  • Humidifier producing loud noises and not misting.

Solutions:

  • Remove the cover, unplug the unit, and inspect for any loose parts.
  • Check if the humidifier fan is loose on its shaft by wriggling it.
  • Tighten any loose screws.
  • Check for any clogging in the fan inlet. If there is any, remove it by cleaning.
  • If the device is still under warranty, contact the manufacturer, or Invest in a new humidifier.

5. Bad positioning.

A humidifier may not be misting be due to its positioning.

The amount of mist produced by your humidifier is somewhat determined by the location in which it is placed. The misting will be disrupted if it is placed on anything soft, such as a towel, that will not absorb the ultrasonic vibrations.

Humidifiers should be positioned on flat and hard surfaces. Running the humidifier on soft surfaces such as towels, mats, or carpets can also obstruct airflow, and cause spills or the humidifier to topple over.

Diagnostic features.

  • Noises.
  • Humidifier toppling over.
  • The humidifier is not turning on.

Solutions.

  • Use a humidifier on a level and hard surface.
  • Check that the lid is secure and that it is seated properly on the unit’s base.
  • Consult the user manual on where to place your humidifier – there are usually guides on the amount of space required along each side, and the front of the appliance.

6. Location.

When it comes to the amount of mist a humidifier produces, location is vital. The humidifier works by dispersing mist or vapor around the house. As a result, its misting is completely reliant on its location.

The humidifier’s mist will go unnoticed if you put it right next to a fan or worse, just below an air conditioner (which acts as a dehumidifier).

Reading the user handbook can help you determine the ideal place for your humidifier in order to get the most out of it.

Diagnostic features.

  • The humidifier is working, but you cannot see any misting.

Solutions.

  • Place your humidifier away from an Air Conditioner or a fan.
  • If you are not sure where to place your humidifier, consult the user manual.
  • Placing it in the center of the room.

7. Wick filters need to be changed.

The reason an evaporative humidifiers is not misting can be because it needs new wick filters. Filters are only used in some humidifiers, but when they get clogged, water will not pass through easily and ultimately lead to inadequate mist. 

Check the wick filter on an evaporative cool mist humidifier to determine if it needs replacing.

Diagnostic features.

  • Musty odors coming out of the humidifier when it is working.
  • The water in the humidifier tank is not emptying as fast as it usually does.
  • Lack of mist.

Solutions:

  • Check to see if the wick filters are clogged.
  • If they are clogged, replace them.

How to replace wick filters

  • Ensure the humidifier is unclogged and the main power source is switched off.
  • Disassemble your humidifier by removing the tank from the base. 
  • After that, simply lift the filter cover up carefully.
  • Access the wick filter.
  • Remove it and dispose of it.
  • Unwrap the new wick filter and place it where you removed the old filter.
  • Reassemble your humidifier, pour some water in it, and connect it to a source of power ready for the next use.

Note: The instructions for changing the wick filter may change from one humidifier model to another. Always consult your user manual for model-specific instructions.

Humidifier not turning on

When a humidifier “doesn’t turn on,” it means it isn’t doing anything at all, it doesn’t switch on or even mist. This applies to all kinds of humidifiers, i.e., ultrasonic, evaporative, cool mist, warm mist, and vaporizers.

Reasons for a humidifier not turning on:

1. Not plugged in.

One simple but common reason for your humidifier not working is that you haven’t plugged it in or that you have, but not correctly as it should. Confirm the cord is completely placed into the outlet for it to work.

Two plugs are normally included with a humidifier; the power cord that connects to the power source on one end, and the cable that connects to the humidifier on the other end. If your humidifier has plugs, double-check that they’re plugged in and it is working correctly.

Diagnostic features

  • The humidifier not responding at all.

Solutions.

  • Make sure you’re using the right power adaptor.
  • Double-check that the power adapter is securely inserted into the wall outlet.
  • Check if you have plugged in the humidifier.
  • Ascertain that it is properly plugged in.
  • Make sure the humidifier’s power source is firmly hooked into the back socket.
  • Check to see if the unit is level.
  • Check if any breakers in your home’s fuse or breaker box have been tripped.

2. Power cord related issues.

One of the most common reasons your humidifier isn’t operating is because the power source it relies on isn’t working. A humidifier, like any other home equipment, will not work or turn on if the power cord or electrical system is damaged.

If the power cord is damaged, most humidifiers will not work. To work, most humidifiers, such as vaporizers and ultrasonic humidifiers, need to be hooked into a power source, such as a wall outlet in your home.

Diagnostic features.

  • The humidifier does not turn on or do anything whatsoever.

Solutions.

  • Try plugging your humidifier into a separate outlet in your house.
  • Confirm if there is power.
  • Make sure the cord is fully inserted into the outlet.
  • Try plugging in another electric item, such as a kitchen appliance, to see whether it works.
  • If your humidifier has control lock features such as the child lock safety, check to see if it is activated.
  • Replace your plug or outlet depending on the primary issue.
  • Test whether your power supply is at fault by plugging a different appliance rather than your humidifier to check that the unit is receiving enough power.

Humidifier not staying on

A humidifier that does ‘not stay on’ is one that turns on but then turns off after a short period of time, making it difficult to humidify a room. It is applicable to all humidifiers.

Reasons for a humidifier not staying on:

1. Water contamination.

Water contamination in the electrical components is a common reason why a humidifier will not stay on.

The contamination is caused by water entering the components, often during use, but more typically when filling the reservoir.

It may begin to shut down more frequently if it does not totally stop working, preventing it from appropriately humidifying a room.

Water enters the electrical components when you place your humidifier on an uneven surface, remove the lid while the humidifier is running, or if something inside an ultrasonic humidifier breaks and allows water to escape.

If you overfill the water and it spits out of its reservoir, water can also enter the electrical components.

Diagnostic features:

  • Your humidifier keeps turning off time after time.

Solutions:

  • Do not operate your humidifier without the lid on.
  • Do not place your humidifier on an unlevelled surface.
  • When using any kind of humidifier, use the amount of water directed by the user manual.
  • After cleaning your humidifier, allow it to completely dry before using it again.
  • Take it apart and examine for dampness on the electrical components or pooling in the bottom of the humidifier.
  • If water reaches the circuit board or the fan, unplug the machine, remove any water, clean it and let it completely dry before using it again. 
  • Allow the humidifier to dry completely by placing it upside down on a towel overnight.

2. Settings.

Incorrect settings can result in your humidifier not staying on (i.e. keeps turning off).

Most humidifiers come with humidity control settings, or a humidistat.

Your humidifier could keep turning on because of certain settings. For instance, setting your humidifier not to exceed a certain percentage will cause your humidifier to automatically turn off when the relative room humidity reaches that particular percentage.

Diagnostic features:

  • The humidifier keeps shutting off.

Solutions:

  • Navigate to settings to check if you have any setting preferences.
  • Remove the settings or change them based on the current relative humidity.
  • Some humidifiers even allow running without humidity restrictions, for instance, the PARIS RHÔNE humidifier. Simply select the automatic setting.

3. Faulty humidistat.

The humidistat plays a vital role in maintaining humidity levels. Any fault in it can interfere with the normal working of the humidifier.

The humidistat senses and regulates the relative humidity of the surrounding air, with users able to set a limit based on their preference. Once the set level is reached, the machine stops working temporarily until the humidity drops again.

Relative humidity should ideally not exceed 50%. If you notice an abrupt decrease in humidification, a faulty humidistat is likely the cause. When the humidistat misdiagnoses the relative humidity of the room it switches off, thinking the humidity of the room is different to what it is in reality.

Diagnostic features:

  • The humidifier keeps shutting off (but does turn on).

Solutions:

Connect a multimeter to the system and supply varying voltages. If the ohm-meter reads correctly, you need to reset your humidistat. But if the ohm-meter reads zero constantly, your humidistat is not working.

4. Faulty or incorrectly placed float.

Many humidifiers have a float system that regulates an automatic on/off function on the humidifier.

It stays at or above the activation point until there is enough water in the tank.

Once the tank is low on water or runs out of water, the float drops below the activation point, and the humidifier turns off.

After refill, a functioning float will reposition itself for the machine to resume working.

Mechanical errors or mineral deposits can cause the float to become stuck below the activation point, and even though the tank has sufficient water the humidifier will switch off.

In this case, the humidifier will often display a red light and will not work.

Diagnostic features:

  • The humidifier keeps shutting off (but does turn on), and the water tank is full
  • Float is not above the activation point.

Solutions:

  • Dust or limescale accumulation can cause damage or impinge the float system.
  • Clean the debris with a cloth or soft brush, and then move the float with your hand.
  • Position the float at the level of activation.
  • If the humidifier does not start working, replace the float switch.

Humidifier Leaking water

A humidifier that ‘leaks water’ is one that turns on and humidifies the room, but it keeps leaking water around where it is placed.

Reasons for a humidifier leaking water:

1. The lid cap is not sealed correctly.

A humidifier leaking water can be because the lid cap is not sealed or not sealed correctly.

All humidifiers come with lid tops that should be covered while in use.

If you operate your humidifier without covering it with its lid, it may leak water. The lid is designed to keep water from leaking out while the device humidifies a room.

Diagnostic features.

  • Water leaking.
  • Loud noises.

Solutions.

  • Cover your humidifier while in use.
  • Inspect the reservoir for cracks, and replace if necessary.

2. The Humidifier is placed on an uneven surface.

Placing the humidifier on an uneven surface can result in water leaking, especially if you move the humidifier from one place to another.

Manufacturers always recommend placing a humidifier on a hard and flat surface.

Diagnosis:

  • Humidifier leaking water.
  • The humidifier appears uneven.

Solutions:

  • Placing the humidifier as specified with the user manual recommendations.
  • Avoid placing the humidifier on soft spots, towels, or mattresses.

3. The reservoir tank is not placed on the base correctly.

Some humidifiers have water tanks that need to be placed on the base in order for them to humidify a room—mostly ultrasonic humidifiers.

If the water tank is not correctly positioned on the base, it can leak water.

Diagnostic features:

  • Humidifier leaking.

Solutions:

  • Check if the reservoir tank is correctly seated on the humidifier base before turning it on.

Humidifier Spitting water

A humidifier that ‘spits water’ is one that turns on but keeps spitting water whilst it humidifies the room.

Reasons why a humidifier leaks water:

1. Filling water past the max line.

The reason a humidifier is spitting water is likely because you filled the water above the max line. Humidifiers have the max line that you are supposed to fill to, but not beyond.

If you fill water past the max line, it could start spitting.

Diagnostic features:

  • Humidifier spitting water when it is turned on.

Solutions:

  • Do not fill your humidifier tank past the max line.

2. Mineral build-up.

Mineral build-up in your humidifier can also lead to it spitting water while humidifying. The build-up is a result of using hard water in the humidifier.

Diagnosis

  • White scale or buildup in the humidifier.

Solutions

  • Use distilled water in your humidifier and clean it regularly.
  • Unclogging the humidifier and removing any scale/limescale deposits (warm water and soap should be sufficient, but lemon and vinegar can also be used where necessary).

Humidifier Making excessive noise

A humidifier that ‘makes excessive noise’ is one that does turns on, and may even humidify, but produces a lot of noise.

Reasons for a humidifier making excessive noise:

1. Broken/damaged fan

One reason why your humidifier is making noise is a broken or faulty fan.

If you can’t hear the fan, but you are hearing other loud noises, and there’s no mist coming out, the fan is likely the issue.

The water mist in most humidifiers is dispersed by the fan.

If the humidifier’s fan still turns on but doesn’t disperse water vapor, it’s probably broken. The fan’s main job is to push the mist out of the compartment; if it doesn’t, no mist will emit.

Diagnostic features:

  • Humidifier producing loud noises.

Solutions:

  • Using oil, lubricate the fan motor bearings.
  • Remove the cover, unplug the unit, and inspect for any loose parts. Tighten any loose screws.
  • You can find other essential care and maintenance measures to keep your humidifier running smoothly and efficiently in the owner’s manual.
  • Check if the humidifier fan is loose on its shaft by wriggling it.
  • Check for any clogging in the fan inlet. If there is any, get rid of it by cleaning.
  • If you suspect a clogged air vent, try blowing into the fan or directing puffs of air into the entry with an empty squeeze bottle.
  • If the device is still under warranty, contact the manufacturer.
  • Invest in a new humidifier.

2. Water reservoir is not stable.

A humidifier can make excessive noise if its reservoir or water tank, is not stable or seated properly.

This is common in humidifiers that have a removable water tank.

If a water tank is not replaced properly, it will vibrate each time the humidifier operates. It typically produces an unpleasant, low pitch noise.

Diagnostic features:

  • To identify if this is the cause, press down or hold the water tank with your hands when the humidifier is on. If the sound is quieter, this is likely the problem. 

Solution:

  • Turn the humidifier off and unplug it.
  • Remove the water tank from the unit.
  • Confirm there isn’t any dirt, debris or moving parts between the water tank and its slot.
  • Check there is nothing stuck to the outside of the water tank itself.
  • Replace the water tank into its slot gently. Usually, there is a clicking noise when it fits perfectly.
  • If you notice that the water tank is broken or cracked, consider a replacement.

Russell Singleton

Russell holds a Bachelor of Science (Environmental and Marine Geoscience) with Class I Honors. He is currently completing his doctorate in science and is passionate about all earth processes, especially isotope geochemistry and paleohydrology.

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