On 2006-03-26, Sacramento Dave wrote:

I think pushing a button to start the pump is not solving the
problem, your right back to ware you started. You just added a pump
to push the cold water back into the hot water tank, you still have
to wait for the cold to clear the system, kind of like opening the
fixture and letting the cold run out. So all you have gained is the
joy of pushing a button.

Umm, the comparitively small amount of cold water in the hot water
pipe will not significantly impact the temperature of the water in the
hot water tank. From the user's point of view, it will basically "go
away". To wit: a 50' run of 3/4" type M pipe holds 1.34 gallons of
water. If the water in the pipe has cooled to 40 degrees, and the hot
water tank hold 40 gallons at 120 degrees, then putting that cold
water back into the hot water tank will lower the tank temperature to
117 degrees.

Cheers, Wayne