46erjoe wrote:

The home I recently bought has a hot water heater that is different
from any I've ever seen before. There is a fan blower on the top of
it, so that every time the hot water heater kicks on, so does the
blower. Seems odd to me. Hot air rises. But I do notice that the
exhaust is out the side of the house about rather than through the
roof. Is that why? Thanks.


http://www.ho****er.com/products/residential/gas.html

Called a Power Vent heater (or you might have a Direct Vent).
Instead of having a chimney, the draft blower sends the
combustion gases out the side of the house.

Not needing a chimney, they can be located more
conveniently.