Honeywell Humidifier Red Light: Don’t Panic, It’s Fixable!

Honeywell humidifier red light shows that something is wrong with your unit. But there is no need to panic just yet.

Off the tip of my fingers, here are the most common causes of red light on your humidifier:

  • No water or low water level in the tank
  • Dirty filter or filters due for replacement
  • Improperly fixed tank
  • Problem in wiring and circuitry
  • Damaged or dirty water sensor
  • Humidifier requires to be reset
  • Others

As you can see in our post on Honeywell humidifier instructions, it is possible to fix many of the troubles that these appliances experience.

Mostly, both Honeywell filtered and easy to clean no filter humidifiers do display a red light from time to time. The red light tells you there is a malfunctioning of some sort.

Will the humidifier keep turning off if there is a red light? Some do, and some don’t! This is one of the things we shall look at here.

What does the red light on my Honeywell humidifier mean?

Honeywell humidifier red light

A red light is a warning that something is not right with your humidifier. If you see it, it is better to switch off the unit until you can figure out what is wrong.

Here are the most possible causes of your humidifier light illuminating red:

1. The tank does not have enough water

If the humidifier tank has less or no water, it is going to show a red light. A humidifier uses water to create mist, which it releases into your indoor air. Therefore, the humidifier water level keeps going down!

When the water is out or less than ½ inch, it will show a red light. This should be fairly simple to check, especially since Honeywell Humidifiers like HCM350 come with transparent tanks.

To solve this, switch off the unit and allow it to cool down for about 20 minutes. Remove the tank from the unit, turn it upside down to remove the cap and fill with distilled water.

It is good practice to clean the humidifier before you fill it with water. This can help to get rid of mold in the humidifier.

Remember, exposure to this fungus can cause mold toxicity symptoms, which are dire for your children’s health.

Also, do not use tap water in the humidifier since it might contain minerals, which will form scale in the tank.

2. The filter is dirty

Honeywell humidifier filter

If you read Honeywell humidifier reviews, you will see that some of them come with filters. If yours has one, follow the recommended cleaning procedures from the humidifier cleaning instructions.

Even if the humidifier does not have a filter, it can still show a red light.

With filters, check whether they are due for replacement. If they are, change them. You could order the appropriate filters for your Honeywell humidifier model from

For washable filters, clean them under running water in the sink, air-dry and then re-install them back in the unit.

If your humidifier filters stay dirty, they could cause the spread of bacteria with the mist. This is one of the things that cause humidifier sickness symptoms.

For a filter-less humidifier, you still need to clean it. If scale forms on the tank walls, it can prevent the unit from working correctly and it can cause the red light.

To remove scale from the walls, pour a cup of white vinegar in the tank and 0.5 to 1.0 gallons of water. Let it stay for about 30 minutes, then pour it out and rinse thoroughly.

If there is stubborn scale on the tank walls, you can use an old toothbrush to remove it. This only works if the unit cap is large enough to allow your hand to get in.

3. Humidifier needs resetting

In the article on Levoit humidifier not working properly, we said you can reset it. Resetting a humidifier is simple since it just means switching it off for an hour or two and then switching it back again.

Unfortunately, by design, even the best humidifiers do not come with a reset button. Thus, you have to switch it off and unplug it from power for some time.

If the tank and filters are clean, and if the water level is good, the reset should work. If it does not, there could be a deeper underlying problem with the humidifier.

4. There is a problem in the circuitry

If water gets into the circuitry, the humidifier keeps turning off after cleaning. There is also a chance that a problem in the wiring is going to cause the red light to come on.

Do not tamper with the wiring. Opening the humidifier base is going to void the warranty. If it is not under warranty, you could still mess up the wiring and cause the unit more harm than good.

If the unit is under warranty, contact Honeywell or check their official website. They have incredible support channels for different humidifiers. For instance, if you have a cool mist humidifier, they have a support channel for that.

If it is not under warranty, you could try to fix it yourself. Even then, do that only if you are very good with your screwdriver and hands. If you are not, take it to a technician.

Sometimes, you do not have to access the circuitry. Just remove the tank and place the humidifier base on a rack upside down. Leave it to air-dry for several hours or for a full 24 hours.

Honeywell humidifier red light when full

Honeywell humidifier red light when full

It is possible to have a red light showing on your Honeywell humidifier when it is full. If this happens, possibly, there is mineral scale on the tank.

If you have cleaned the tank recently, changed the filters and everything is right, well, there is something wrong with the wiring and the circuitry.

The red light on the Honeywell humidifier might also go on if the unit if the cap to the water tank is not secured on tightly. If it is not, the red light can come on.

If this is the case, just remove the tank if the cap is located at the bottom, twist it in the clockwise direction properly until it is tight and then re-install the tank. The red light should go off.

Water sensor level is damaged or dirty

Humidifiers have a water level sensor. It has to be working correctly for the humidifier to work. The sensor can sustain damage and if that is the case, order a new one and replace it.

If the sensor is just dirty, just wipe it clean with a damp piece of cloth.

These are the most common causes of a humidifier showing a red light even when it is full, clean and has new filters.

If you check everything and the unit still shows a red light, it might be a serious factory defect, especially when it is new.

Red light keeps coming on

Sometimes the red light on the humidifier will go off and come on soon again. The most likely cause for this is filling the tank to the brim with water.

It is always best to fill the tank to about ¾ of its capacity. That way, you not only prevent the red light from coming on, but it also stops the unit from spilling on the floor or the table.

You must also keep the humidifier on an elevated stand so that it has proper airflow from all around. Since the vents are at the bottom, you do not want anything blocking them.

The red light will keep coming on in a warm mist humidifier if the heating elements are coated in scale.

To rectify this, unplug and let it cool down, remove the tank and access the heating element compartment attached to the base.

You can fill the heating element area with water-vinegar solution. Let the heating element soak for sometime to get rid of the scale. You can then wipe the heating element with a damp piece of cloth.

Honeywell top fill warm mist humidifier red light

Honeywell top fill warm mist humidifier red light

Top fill humidifiers are so easy to fill. Honeywell has a good number of these, both as ultrasonic, cool mist or warm mist models.

A warm mist humidifier will have the red light because of all the factors that we have mentioned here. However, warm misters release vapor into your room to combat the symptoms of dry air in the house.

To boil the humidifier water, they use heating elements, and these can be caked with scale if you use hard water or tap water.

Therefore, for warm mist humidifiers, the heating elements are most likely to blame for the red light if you have checked all the other things.

Honeywell humidifier not working red light

If the Honeywell humidifier water level not going down, it’s not releasing mist into your indoor air.

Mostly, when something is wrong with a humidifier, it is likely to shut down altogether, which is a good thing.

For instance, if the unit runs out of water, it can shut down to avoid overheating. But some can continue running and that is how you can experience a Honeywell humidifier burning smell.

Therefore, we suggest shutting down the unit as soon as you see the red light come on. This can prevent damage.

Since the red light is a warning that something is wrong, shut the unit as soon as you see the red light.

In any case, even if it does not shut down on its own, the unit will not produce mist, so either way, it is not going to work.

Here are simple checks to do if the humidifier shoes red light and does not work:

  • There is no water in the tank
  • The filter is dirty and clogged
  • The sensor is damaged or dirty
  • The unit has a problem in the wiring
  • It just requires resetting


A humidifier shows a red light to warn you something is wrong. The most common culprits are easy to fix.

But you should not attempt to dismantle the base when the humidifier is under warranty because you will void it.

Always start with the simplest checks that do not require you to dismantle the unit. If they fail to turn the red light to green, you can check the circuitry of the unit.

Honeywell makes good warm mist and cool mist humidifiers and the need to return them rarely arises.

Clean your unit all the time. Also, if you use accessories such as a demineralization cartridges for humidifiers, clean them too.