Honeywell Humidifier Red Light Stays On – What To Do?

If you’re savvy with electronics, you’ll know that when a red light appears, it’s like the appliance is giving you a side-eye and saying, “Hey, something’s not right here.”

When a Honeywell humidifier illuminates red light, it often means the water level is too low, the water sensor is faulty or the UV light needs a replacement, but it could be other issues too.

Don’t worry, we’re here to help you decode this red light mystery and show you how to address and prevent it. 

Without further ado. Let’s get started!

Why is my Honeywell humidifier showing a red light?

Honeywell offers a wide range of humidifiers, and the causes of red light can vary depending on the specific model. We try to provide as much information as possible.

1. The water level is too low.

Nowadays, most Honeywell humidifiers have an auto shut-off feature. When the water level drops to a certain level, it will stop working and a red light will show up to remind you to refill it.

2. UV light needs to be replaced.

honeywell humidifier red light 1

If the model you have is HCM350, the red light is telling you that the UV light needs to be replaced. After 3,000 hours of operation, the UV bulb will be closed to the end of its life.

3. Faulty water level sensor.

Sometimes, the red light will stay on even when the water tank is full. As you know, these humidifiers make use of a water sensor in the base to monitor the water level. If it gets stuck, your Honeywell humidifier will still think it is running out of water even if the water is sufficient.

4. Overheat

If your Honeywell one produces a warm mist, like HWM340, the red light may indicate that the machine is overheated. If you continue to use the full heat setting, the heating elements may not be able to function well.

5. Mineral deposit

This happens more frequently in ultrasonic models because evaporative models have a filter to filter out the majority of impurities.

When the mineral deposit clogs the nebulizer, it is not able to vibrate, causing no mist to come out of the machine and red light to show up.

6. Water gets into the circuitry

Don’t add water to the base, because the water can easily get into the circuitry. If you find your humidifier stops working after cleaning and the red light stays on, there is a high likelihood that the circuitry is damp.

What to do if my Honeywell humidifier has a red light that stays on?

Now that you have known all the common causes, let’s explore how to resolve them. Luckily, most of them are easy to fix. 

1. Adjust the settings 

If you happen to have a warm mist model, the first step is to switch it to the lower setting. When the temperature falls, the red light will turn off automatically.

2. Adding more water to the tank.

Nine times out of ten, the red light in the Honeywell humidifier is due to the lacking of water. Therefore, you can refill the water tank and then wait for one or two minutes to check if the red light turns green.

3. Clean or replace the water sensor

The stuck water sensor can cause the red light to stay on and in many cases, a thorough cleaning can bring it back to life.

You can dump the water in the base and use a soft cloth to wipe down the float and ring in the sensor. Some vinegar can help with removing the mineral buildup inside.

In rare cases, the sensor may be broken. Since it is cheap, you can contact the manufacturer to get a replacement.

4. Clean the atomizer

If none of the methods above work, the atomizer could be the culprit. To remove the deposit on it, you should add some vinegar or citric acid to it. Let it sit for 20 minutes and then use a soft brush to clean it.

5. Replace the UV lights

honeywell humidifier UV light

If you are an HCM350 owner and your humidifier has operated for a long time, it is highly possible that the UV light needs to be replaced. 

As for changing the UV bulb, you should remove the water tank, locate the bulb cover and then use a Phillips screwdriver to remove the screws on it. Then you can replace the old bulb and bulb socket with the new ones. 

6. Air dry the humidifier

If you doubt some water has got into the circuitry, you can allow it to air dry for a few days and test it again. Don’t try to disassemble your Honeywell humidifier unless you are a technician. 

How to prevent the red light in your Honeywell humidifier from illuminating again?

If you don’t want to be bothered by the red light again, there are some ways you can avoid it.

Use distilled water 

Using distilled water is an excellent way to prevent mineral buildup, which is the primary cause of the red light. In addition to keeping the red light at bay, it can also benefit the health of your family members.

If you think distilled water is costly, you can try to make it at home

Clean it regularly 

Standing water in the humidifier can be harmful to both your health and the humidifier itself. A filthy humidifier often leads to a malfunctioning atomizer.

Refill it every day 

While you can buy a humidifier that has a big water tank and can run for a few days per fill, I still advise you to empty the tank and refill it on a daily basis. This can not only ensure the red light will not stay on but also prevent the water from being stagnant.

Sum up 

When you see your Honeywell humidifier has a red light stay on, please calm down. More often than not, it is because the cleaning is overdue or it runs out of water. Even if it is due to the broken water sensor, it is still easy to fix. 

I hope this guide has helped you to solve the problem and you can find more useful information about using a humidifier on our website.

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.