Instant Brands HEPA Quiet Air Purifier

So it worked for about a week with absolutely no problems at all every function worked flawlessly and efficiently as well. After a week the I noticed a loud noise coming from the unit while it was on a low speed. Went over to it and turned off the ion option and the noise stopped. No matter what I tried the noise kept coming back on any speed and any setting even after unplugging it still no go. No problem still works and does what it's supposed to without that I can live with that. About a week later and the auto feature starts messing up. While it's in the red telling me it's bad it goes to orange then white within seconds. Then it would do this over and over again without fail. Turned it off and back on and did the same thing. Sensor might be bad I don't know. I loved this unit before those two problems. I docked a star for each and sent it back but if you buy it and it works with no issues it is fantastic! Kept the smells away and helped with dust while it worked right. Price went way up and I couldn't exchange so I ended up buying the next model up which has a better air quality sensor and shows you the actual number it's at. I hope this helps!