The average family can dump 10,000 gallons or more down the drain every year waiting for hot water.  That’s half a swimming pool wasted!  If only there was a way to save all that water…  hmmmm…

Luckily there is!  A recirculation pump (retrofit or dedicated return line) can save water from being wasted and the corresponding money. 

How do the retrofit systems work you ask?  The problem of course is that water heated by your water heater sits in the line between the heater and the tap(s) where it cools off. Let’s call this “previously hot” water. When you turn on the tap you need to flush out this previously hot water to get to the fresh hot stuff. With low-flow faucets and long plumbing runs, this can take a long time – and waste a lot of water.  An instant hot water system – or hot water recirculation system – flushes the previously hot water back into the hot water tank (rather than you running it down the drain) through the cold water line, so you have freshly heated water waiting for you when you turn on the faucet – instant hot water. 

Metlund and Laing pumps:
http://www.hvacquick.com/products/residential/Instant-Hot-Water/Hot-Water-Recirculation-Pumps-NON-TANKLESS