Originally Posted By: wfaulk
Hm. Maybe so. Maybe the extra water being put into the cold water lines will feed back into the hot water tank. Honestly, I'm still a little unclear on how the house's pressure defeats the municipal pressure in any case.


That heated water comes from the cold water line.. so if we're taking water from the hot water heater, it's really coming from the cold line. So circulating back to the cold line just cancels that out.

There may still be a separate code requirement for a backflow preventer, but that's something which is good for garden hoses and even the normal hot water supply as well.

Cheers