On Fri, 16 Jun 2017 10:50:10 -0400
"Jim Wilkins" wrote:

snip
There are wireless motion detectors that would turn on the pump to
circulate water only if someone was in the room. When I posted that
the problem was poorly specified I meant the conditions that might
turn on the pump to anticipate need, rather than wastefully running it
continuously.

This system/company supplies a variety of different switches & buttons
to work with their solution. Their solution isn't what Eric wanted but
I suspect some of these accessories may work with other setups:

http://www.gotho****er.com/plumbing-parts

I found this guy's website interesting. It can get pretty expensive to
have that hot water ready at the faucet:

http://www.builditsolar.com/Projects...circEnergy.htm

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email