
Blueair purifiers are designed with an LED that turns red when it’s time to replace your air filter. This is a useful feature that helps protect the longevity of your purifier, since dirty filters increase strain on the unit.
So if the touch light on your Blueair purifier has turned red, know that the unit believes it’s time to replace the air filter.
To reset the red light on your Blueair purifier, first replace the air filter. Then press and hold down the touch button for 3-7 seconds, or until the red light turns off. This will restart the timer and the red light should turn off for the next 5-6 months. Certain issues can cause the red light to turn on sooner, however.
The rest of this article will go over the steps involved in changing your Blueair filter and what to do if the red light won’t reset.
How To Reset Blueair Filter

To replace and reset the filter on a Blue Pure air purifier (like the one shown above), follow these steps:
- Turn off the air purifier and unplug it.
- Push down on the top cylinder and rotate it counterclockwise to remove.
- Open the pre-filter panel on the side of the air purifier and take out the pre-filter. You can vacuum it or throw it in the washing machine for a deeper clean.
- Lift up the filter shelf ring, then use the filter handles to lift up the main filter.
- Take your new filter and lower it into the inner structure, making sure that the handles are facing up.
- Put the filter shelf ring back into position and push it down firmly to secure.
- Place the pre-filter back into the unit and close the pre-filter panel.
- Push the top cylinder back onto the main unit and, while still pushing, rotate it clockwise to lock.
- Plug the unit back in and press the touch button for 7 seconds to reset the filter timer.
That’s all there is to it! You will now have a clean pre-filter and filter, and the unit’s internal replacement timer has been reset. The touch light should not turn red until it’s time to replace your filters again.
How Often Do Blueair Filters Need To Be Replaced?
Generally speaking, you should replace your Blueair filters every 6 months. This makes a few assumptions about the average air quality in your area and how often you run the air purifier.
You can go to AirNow.gov to see what the air quality in your city has been over the past month. Just enter your ZIP code and then click on “Recent Trends” and scroll down to the month view.
For example, here’s the past month for Tucson, AZ:

If the air quality in your area has a lot of days with an AQI over 50 like in this chart, it might make sense to replace your air filter every 3 months instead.
Here’s another example from Raleigh, NC:

If your air has been relatively clean and has mostly stayed below an AQI of 50, like the chart above, you may only need to change the filter every 9 months.
As you can see, the recommendations vary, which is why Blueair recommends splitting the difference and changing the filter every 6 months. This is the frequency that will work best for most people.
What To Do If Blueair Red Light Won’t Turn Off
If pressing and holding the touch button for 7 seconds doesn’t reset the red light, or if it comes right back on, you might need to try a full reset of the air purifier.
It’s a straightforward process and it only takes a minute or so.
To fully reset the filter light, follow these steps:
- Press and hold the touch button until the unit turns off.
- Unplug the unit from the outlet and wait for 60 seconds.
- Plug the unit back into the outlet and turn it on using the touch button.
- Press and hold the touch button for 7 seconds, then release it.
This combines a power cycle of the air purifier with the reset process for the air filter replacement indicator. Completing this full process should get rid of the red light on the top of the unit.
If you’re noticing a red light somewhere else on the Blueair purifier, it might be the air quality indicator.
Clean The Air Quality Sensor

If you have a Blueair model equipped with an air quality sensor, dirt can build up over time and cause the air quality indicator to remain red.
To clean the air quality sensor, follow these steps:
- Turn off the air purifier and unplug it.
- Push down on the top cylinder and rotate it counterclockwise to remove it.
- On the top cylinder, locate the small lid that covers the air quality sensor on the side and press it.
- Remove the lid and use a cotton swab to clean the sensor and surrounding area.
- Place the lid back over the air quality sensor.
- Put the top cylinder back on the unit and rotate it clockwise while pressing down gently.
Where To Find Replacement Filters
You will need to use official Blueair replacement filters in order to get the best performance and to avoid voiding your warranty.
The good news is that Blueair sells official filter replacements through Amazon, so it’s easy to order and you can get a 5% discount when you subscribe to automatic deliveries every 6 months.
You can order replacement filters from Blueair through Amazon and enjoy fast and free Prime shipping.