Do not use a fan heater upside down attached to the ceiling. When the motor fails, the overheat cutout is at the bottom instead of the top and does not switch it off. The casing then catches fire (I thought that kind of plastic was fireproof!) - luckily I walked past it as it did it and smelt burning. Although I notice another brand (Micromark) to that one (Glen) doesn't even have a cutout....