Blue Air Purifier Red Light Problems: 5 Reasons and Troubleshooting

Are you facing a Blue air purifier red light issue and don’t know what this means and what to do? If so, you are at the right blog post. The red light turning on can be worrying as it can indicate serious problems with your device.

However, to get you out of this worrisome situation, I’ll discuss common causes behind this problem and a simple 5-step guide to get rid of them. Let’s get going!

Quick Answer

A red light on the Blue air purifier indicates there may be an issue with the unit. However, you can quickly fix that with these steps:

  1. Cleaning the prefilter;
  2. Replace the old filter;
  3. Clean the purifier;
  4. Reset the unit.

However, the above steps are just the tip of the iceberg. You may have to change the purifier location as well as update the unit. Continue reading as I will uncover detailed troubleshooting steps and 6 additional helpful tips to eliminate that offensive red light in the following sections. Let’s dive into it! 

Related Topic: Homedics Air Purifier Red Light: 4 Reasons and Best Fixes

An Insight Into the Blue Air Purifier Red Light

Blue air purifier gives red light which is a precautionary indicator that there is an issue with the device or the air quality. Some common red light culprits include the following:

  1. A dusty and clogged-up air filter;
  2. Blocked air vents trapping airflow;
  3. Faulty fan and motor;
  4. Malfunction in the sensors;
  5. Fussy electrical issues.
Causes of The red light on the blueair purifier

Determining the Filter Life

A filter on an air purifier usually lasts for 5-6 months. The following tips can help you keep track of the time when to replace the filter:

  1. Check the manufacturer’s guidelines: A company can best determine the life of a filter. You can also get help from the user manual.
  2. Look for an indicator sign: A red light is the strongest indicator of filter replacement. In some devices, the blue filter light turns yellow. This is also an indicator for filter swapping.
  3. Note any decrease in airflow – If you notice the airflow volume dropping, the filter is likely getting clogged and about to expire.
  4. Check for physical damage: Look for the signs of being worn out, heavy dust, and damage as these can end the life of a filter beforehand.
Determining the Filter Life

Pro tip: You can turn off this red light temporarily in Blueair air purifiers by holding the filter light or button for 10-30 seconds. However, if you don’t replace the filter, it will turn on again. 

Understanding the Lights on Blueair Air Purifiers

Blue air purifiers have 2 different lights that show the current air quality status and the filter’s life progress. Let’s discover the details:

  1. Filter replacement light: Red light shows there is something wrong with the filter and it needs to be changed. Also, this indicator may glow yellow in some devices. This indicates that the filter is nearing the end of its service life.
  2. Air quality lights: In Blueair air purifiers addition to the red light, you may encounter lights, such as white, blue, green, yellow, and orange. These lights tell about the air quality or the normal operation of the unit.

For a better understanding of the air quality lights, let’s check out the table below.



White light

White light

The device is turned on

Blue light

Blue light

Excellent air quality

Green Light

Green Light

Good Air Quality

Yellow light

Yellow light

Moderate air quality or filter needs a replacement soon

Orange light

Orange light


Red light

Red light

Very polluted or filter needs immediate replacement

Important to note that not every model has both indicators. In fact, some models have only one light indicator. Check out the table below to find out the reason for the red light on your unit: poor air quality or the filter issue.


Filter Replacement Indicator

Air Quality Indicator

Blue Pure 211i Max_Filter Replacement

Yes. On the top panel

Air Quality Indicator_Blue Pure 211i Max

Yes. In front of the device

Blue Pure 511_Filter Replacement

Yes. On the top panel


Blue Pure 121, Blue Pure 221

Blue Pure 121_Filter Replacement

Yes. In front of the device


Filter Replacement_Blue Pure 311 Auto

 Yes. On the top panel

Air Quality Indicator_Blue Pure 311 Auto

Yes. In front of the device

5 Steps Guide to Fix Blue Air Purifiers Red Light Issue?

Let’s have a look at this table to quickly understand the reason behind the red light and their solutions:



Dirty Pre-Filter

Scrubb the prefilter

Technical glitch

Reset the device

The purifier is heated

Let it cool down for some time by taking out the plug

There is high pollution in the air

Change the location of the purifier or minimize the pollution source

Now that we have gone through the table, let’s discuss them in detail.

Materials and Tools Required

Before starting the work on the air purifier red light issue, it’s handy to have these supplies:

  1. Replacement filters;
  2. Small vacuum or duster;
  3. Outlet tester;
  4. Owner’s manual for unit-specific troubleshooting tips;
  5. Cloth and cleaning solution.

Related Topic: Aroeve Air Purifier Red Light Issue: Main Reason and Easy Fix

Step 1: Scrub the Pre-filter

The pre-filter catches large particles before they clog up the primary air filter. Therefore, it makes sense to clean the pre-filter. Follow the given steps:

  1. Unplug and turn off the unit;
  2. Remove the upper lid;
  3. Spot the pre-filter there and remove it;
  4. Look for the signs of dust and debris and scrub them with the help of the duster;
  5. Try vacuuming or washing with lukewarm the pre-filter to clear any significant buildup.
filter change Blue Air Purifier
Credit: @BlueairTube
Important note: If the pre-filter is in quite bad condition, I would recommend replacing it. You can use BLUEAIR Blue Pre-Filter for this purpose. It is made of washable fabric that can effectively trap the pet hair and dust.

Step 2: Reset Your Blueair Air Purifier

If the light persists, it may be because of a technical glitch. Resetting the device can help you in this regard. Follow these points:

  1. Turn off the unit and unplug it from the outlet;
  2. Let it sit powered down for a minimum of 3-5 minutes;
  3. Power it again then hold the power button for 10 seconds.

If the red light turns to white, it indicates that the Blue air purifier has been reset, and it should now function without any problem. 

reseting settings
Credit: @BlueairTube

Related Topic: Winix Air Purifier Red Light: 3 Causes and Easy Fixes

Step 3: Turn off the Unit for a While

Sometimes, if the device is working overtime to clean the air, its motor gets heated. The right approach, in this case, is to let the Blue air purifier have some rest. Follow these guidelines: 

  1. Move it away from heat sources like sunny windows or warm electronics;
  2. Make sure nothing is blocking the vents of the device;
  3. Let the unit cool down for at least an hour before powering it on again.
Pro tip: Don’t forget to check the outlet plug for heating issues. If the heating persists, change the plug.

Step 4: Swap Out the Main Filter

Once the unit is off, now it’s time to replace the filter. Here is how you can do this without any hassle:

  1. Confirm the filter usage over 6 months by checking the installation date marked on the frame;
  2. Remove the upper compartment;
  3. Take off the pre-filter;
  4. Remove the primary filter by pulling it outwards;
  5. Insert the new filter on the frame and set up the system. 
Replacing the filter
Credit: @TruSens

If you are confused about what filter you should get for the unit, the following table can help:


Filter Name

Filter Life

Compatible with Units

Not Compatible with Units


Blue Pure 411 Particle + Carbon Filter

6 months

411, 411+, 411 Auto

311 Auto


Blue Pure 211+ Particle + Carbon Filter

6 months


 211+ Auto


Blue Pure 211+ Auto Particle + Carbon Filter

6 months

211+ Auto



Blue Pure 311 Particle + Carbon Filter

6 months


311 Auto, 411 Auto, 411, 411


Blue Pure 311 Auto Particle + Carbon Filter

6 months

311 Auto

411 Auto, 411, 411+


Blue Pure 121 Particle + Carbon Filter

6 months

Blue Pure 121

Blue Pure 211+

Note: If you are not sure about your purifier model, look out for the rating label. You can find it at the back or underneath your product.

Here is an easy video that takes you through the filter replacement process. 

YouTube video

Step 5: Change the Location

If you have tried out everything mentioned above, the red light is still turning on, which could be an indication of high pollution in the air. In this case, relocating the device can help:

  1. Carefully unplug the unit;
  2. Transport it to a different side of the room in your home;
  3. Close the windows and doors while the purifier is operating;
  4. Restart the Blue air purifier to start the cleaning process.

Additional Helpful Measures To Tackle Red Light

If you’ve tried all the basic fixes, but the red light persists, don’t throw in the towel just yet. A few more advanced troubleshooting techniques may help you get to the root of the problem. Let’s learn about them:

1. Remove the Dust From the Sensor

Dust and debris on the optical air quality indicator/sensor can lead to the activation of the filter replacement indicator light. These steps can help you:

  1. Use compressed air or a soft brush to gently clean the sensor lens at the back of the purifier.
  2. Wipe it gently with a microfiber cloth dampened with rubbing alcohol. Be extremely careful not to press down on the delicate sensor.
filter cleaning Blue Air Purifier
Credit: @BlueairTube

2. Minimize the Pollution

If airborne irritants like smoke, chemicals, and allergens are overwhelming the purifier, you should adopt strategies for removing them. Follow these steps:

  1. Move litter boxes or ashtrays away from the unit.
  2. Decrease the exposure to smoking, pet danders, and hair.

3. Get a New Variant

Sometimes, a Blue air purifier is too small for the space, and it struggles to clean the air, leading to the red light problem. To avoid this problem, you need to upgrade the model.

Go for a model with higher CADR ratings and designed for large rooms such as Blueair Blue Pure 211+ Auto (353/347/380 CADR for smoke/dust/pollen).

4. Remove the Debris from Intake Vent

An air purifier has an intake vent that absorbs the air, which is then filtered and expelled from the top vent. If there is more debris in this compartment, it can also hinder the performance. Follow these steps to clean the intake vents:

  1. Use a vacuum cleaner to dislodge dust and debris inside the vent opening.
  2. Straighten out any kinks or bends in the intake tube.

5. Get the Help of a Professional

An electrical device like an air purifier can face complex internal problems beyond a layman’s understanding. These issues include:

  1. Electrical troubles;
  2. Wiring issues;
  3. Motor heating problems. 

To troubleshoot issues like the above, it is suggested that you consult an appliance repair technician. They have specialized tools and expertise to target internal problems.

filter repair

6. Contact the Company

If all the above troubleshooting fails to tackle the red light problem, it is time to approach the manufacturer. They can suggest whether to buy a new unit or repair the original one. 

  1. Live chat: To get live chat support, go to the Blueair Air Purifier website;
  2. Contact Form: To use the company’s help desk services, use their contact form.

Related Topic: Levoit Air Purifier Red Light: 6 Easy Steps How to Fix It!


How do you know when to change the filter on a Blueair air purifier?

You should change the filter if the unit’s indicator light is red. Moreover, swapping the filter on the Blue air purifiers every 5-6 months is recommended.

How do you reset the red light on an air purifier?

Unplug the unit, then power it on and hold the filter light button for 10 seconds. This will reset the electrical components and air quality indicator light.

What does the red light mean on a purifier?

A red light on a Blue air purifier typically indicates some kind of issue detected, like a clogged filter, electrical problem, or overheating. The red light is a warning sign that the purifier needs troubleshooting.


The final say is Blue air purifier red light indicates that there is an issue with a unit and needs troubleshooting.

If the problem is with the filter, you can replace it. On the other hand, reset the device if the replacement of the filter/pre-filter doesn’t work. Similarly, if there is too much pollution in the room, it is suggested that you should minimize the pollution sources. Finally, upgrading the model can also be helpful if the red light is stubborn. 

Nonetheless, using the company’s recommended carbon filters, cleaning the device, and maintaining the indoor air quality can prolong the cleaner’s life and your usage experience size.