Robert Gammon wrote:


As with most things in life, there is a tradeoff here.

Depending on the situation, up to 15,000 gallons a year of water that
would otherwise flow down the drain while you wait for the hot water to
arrive will be saved as hot water will be virtually instant on every
time. That's on the order of $60 or more per year in water/sewer costs
saved (exactly how much depends on where you live). The pump will
consume maybe $10 of that in a year. The extra utility costs in keeping
the water at a usable temp in the hot water lines during usage hours is
hard to quantify but lets say its an extra $15 a year.


I would imagine that would be an interesting situation. Perhaps whomever
wrote the marketing material for the pump got a little carried away?

We have a house on metered city water with two residents and our *total
consumption* is 19,000 gallons/year.


All hot water lines then need to be insulated to minimize heat loss in
the lines (although here, attic temps are well over 100F in the summer,
so heat loss to the attic is minimial - all water lines are above the
ceiling here)


Yes, it is a MARGINAL benefit and has a LONG payback period. Yet in
areas that are water poor, this can have a much quicker payback, and the
comfort level in the home goes up dramatically.