On Mar 19, 7:12*am, " wrote:
on a tankless feeding a regular tank, it should cost no more to
operate than a regular hot water tank.

the tankless initially heats the water to whatever it can, then sends
the water to a regular tank that does its normal job.

endless hot water regular tank conveniences and the only extra cost is
the line between the tankless and regular tank, ideally it should be
short and well insulated.

true the tank will have normal tank losses.

today i have to stop at home depot and while i am there price some hot
water tanks. just to verify some of these issues

There is no point to this approach, its backwards and will loose you
all the savings you just paid for. If the tankless and tank are 82%
efficent you are heating with one 82% burner and keeping it warm with
another 82% burner. You are heating with the tankless and allowing it
to cool in the tank, at about a 20% reduction in efficency rating.
Most of what you just paid for in increased efficency goes up the
center of the tank and out the chimney. The tank if hooked up should
before the tankless and only hold water unheated to allow it to warm
up by the surounding air to temper it, it works for me. Even better is
to strip of the insulation on the tank, your basement will always be
warmer then the incomming water main.