Last updated on June 2nd, 2022
First of all, Honeywell air purifiers are loud. The HPA300 model can reach up to 71 dB at the maximum speed. So there is not much you can do.
If your unit started making loud noise out of the blue, that’s a different story. The first thing you should do is to contact Honeywell customer support 1 (877) 841-2840. You can also send an e-mail to them on this page.
Obviously, this is not an option if your warranty is outdated. Then make sure that the HEPA filter is installed properly and the structure isn’t compromised.
If everything is ok, then it’s 99% chance that a failed sleeve bearing in the motor is the source of this noise. If you feel confident, you can disassemble the motor to replace them. If the bearings aren’t removable, add a drop of sewing machine oil that will smooth the negative effects.
Replacing the air purifier‘s motor will also fix the problem, just make sure you get the same motor from a seller.