I added a loop to my hot water supply line, but didn't need a pump since
my bathroom is on the second floor, and gravity does all the work; I did
put in a check valve to prevent backflow into the return line.

You save a lot on water and time, but you spend a little more on
whatever you use to heat your hot water. I don't lose that much, since
I live where we have winters, and the return line functions somewhat
like an extra radiator. My loss is during the few months in summer when
we have the air conditioning on, but the extra heat isn't worth whatever
it would take to shut it off for three months.

peter wrote:
I saw this hot water recirculating device at costco. It reduces (eliminates)
the time for hot water to travel to distance faucets by circulating the hot
water.

http://www.wattspremier.com/watts/sh...ID=181&CATID=1

It looks like the water sitting in hot water pipe is being pump into the
cold water pipe, which eventually loops back into the hot water heater.

Has anyone installed this, and does it work well? Does it increase the
heating bill significantly?