u/Superb_Appearance840

So I bought two of these on sale. I have two cats and allergy season is among us.. thought they would help and I think they have but on one of the purifiers, when it's ran on 3 or 4 speed, the red light never turns off. I've tested with the other one which eventually will turn blue.
So I ordered another with the intention to return the one with a faulty sensor... now the new one doesn't go off red on speed 3 or 4.

Has anyone else had this issue or is my air just dirty and the one that eventually turns blue is really just gaslighting me into thinking I have clean air (lol)