A red light on your Blueair purifier means that it’s time to replace your air filter and clean the air quality sensor. First, remove and replace the old filter, then press and hold the touch button for 3-7 seconds or until the red light turns off. The red light will come on again in 6 months to remind you to replace the filter.
Step 1: Remove and inspect the old filter
Turn off the air purifier and unplug it before proceeding. Then, push down on the top cylinder and rotate it counter-clockwise to remove it. Open the pre-filter panel on the side of the purifier and take out the pre-filter.
Next, lift up the filter shelf ring, then use the filter handles to lift up the main filter. Check the filter to see if it needs to be replaced—generally when you can no longer see the main filter material anymore.
Pre-Filter: This is reusable and can easily be cleaned with a vacuum or by throwing it in the washing machine on a gentle, low-temperature cycle.
Main Filter: Used filters can’t be cleaned or reused and can be disposed of in the normal household trash.
Step 2: Clean the air quality sensor
While you have the purifier disassembled, it’s a good idea to wipe off the air quality sensor. This will keep it clear of debris so that it doesn’t trigger the red air quality light.
On the top cylinder that you removed in the previous step, 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 gently clean the sensor and surrounding area, wiping away any dirt or dust. Then, replace the sensor lid.
Step 3: Insert the new filter
Unpackage the new filter and then lower it back into the inner structure, making sure that the handles are facing up. Then put the filter shelf ring back into position and push it down firmly to secure it.
Take the cleaned pre-filter, put it 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.
Step 4: Reset the red light
Plug the purifier back in and press the touch button for 7 seconds to reset the filter timer. This will disable the red light and reset the 6 month filter replacement timer.
Where To Find Replacement Filters
Because of their unique design, it’s best to use official Blueair replacement filters to get the best performance. These are available through Amazon and you can set up automatic deliveries every 6 months with a 5% discount.