I really, really wish I could give 5 ⭐️s. Bought 2 of these units and 3 smaller for bedrooms late Winter/early Spring. They worked FANTASTIC right out of the gate. Now that I've replaced all filters, they squeak, show an orange light indicating not great air quality, and/or flash to replace filter. I've made sure all filters are properly installed. I've cleaned them (just on case). I've sent an email to PuroAir for advice, with no reply to date. I'm hopeful that this review will prompt some help.
In my opinion, the PURO AIR 400 is the best product on the market. In Idaho we had four weeks of dense smoke with air quality in the hazardous level. We were worn to stay inside with the PURO AIR 400. We had no problem breathing in fresh air. I highly recommend this product to anyone that’s looking for an air cleaner.
The PuroAir 400 Hepa Air Purifier is an intuitive small appliance. When we start frying fish or bacon in the kitchen, somehow it is sensed and the PuroAir 400 goes in to high gear to clear the air as soon as possible. The dog traffic back and forth in the great room is not a problem anymore. We're just happy to enter fromoutside and be treated to clean smelling and clear air all the time.