Thanks Mike.
Pictures would do very little good because everything is covered in foam pipe insulation. I have sent you a schematic though.
The system can operate in two modes, timer and thermostat. When the sensor detects that the galley sink hot water supply is below 85 degrees, the valve opens (allows water to flow). The sensor is mounted to short length of copper pipe so good insulation is critical.
Yes, when the pump cycles, there is noise. I have tried to dampen it as much as possible, but it's still there....and I don't like it when sleeping. Hence my move to the radiant heater that also warms the floor (and tank) and, as a bonus, me too.
Smkettner did something sort of similar, but used a solar pump instead.
If I was to do it all over again (and I would for water savings and instant hot water), I would probably just buy a little 30 second timer off eBay instead of building one and I would also eliminate the temperature sensor. KISS
