Bests & Worsts Reviews from Amazon

I ordered 4 of these units from Amazon since late 2013. All of them stopped working within 9 to 18 months. When they were working, they did a great job. Just remember to clean regularly so they don't make 'hissing' noise and don't put them too close to a wall because dirt and contaminents will create a dark spot. I miss not having these things in my house, but I'm not rushing to buy more... I emailed the customer service email of the mfr. asking about 1) repair of units and 2) Warranty. You'll note that there is no warranty information about this product listed on either the Amazon site or the Mfrs. website. I haven't heard anything back from the Wein customer care people - it's been over a week - so I have to assume the obvious: There is no warranty and there is no repair. What that leaves me with is Amazon's A-Z warranty which covers it for 30 days. This is a pretty expensive item for 30 days of air cleaning (worst case). Will I buy another one? Maybe...they do work well when they work. But I expect that these units should last longer than the 4 I've received to date. I also expect a Mfr. to respond to my questions about their product - even a generally negative response is better than no response at all.