It is a bit more complicated than I thought. After reading comments, also read this:http://www.houzz.com/ideabooks/21634433/list/how-to-switch-to-a-tankless-water-heaterThink when the time comes, it woud be great to be able to switch to a tankless system.
@deltadawn:
They are a good idea in terms of efficiency, but in my opinion are not worth the upfront costs over a standard gas water heater. Nat gas is dirt cheap and will be for at least a decade. 4951