I purchased this because it had 4 stars w/ a couple hundred reviews. I received the 1st and noticed it didn't power off right away. It took about a minute for it to stop running. The next day I turned it on to high, the high LED came on, but it never started running. I adjusted it to med, low and off and this time it turned off right away. I called the manufacturer and they said to return it to Amazon. I called Amazon and received a replacement in 2 days. I received the replacement & powered it up and high, med, low & off worked properly. I left it on high for a hour or so & went to turn it off & this time it wouldn't turn off. This time I'm returning for a refund. I read a similar review & they had pretty much the same experience w/ their 2nd one.