I posted a few weeks ago about a problem my BIL had with his zoned hot
water system. The system had a circulator pump on the inlet side of
the boiler and a circulator pump for each of the 3 zones (4 pumps
total). Following each of the circulator pumps was a flo-control valve
(http://www.bellgossett.com/Press/BG-flocontrol.asp ), there are no zone
The problem was the pump on the inlet side of the boiler would kick on
whenever any zone called for heat. The pressure was enough to send hot
water through each zone even if though there was only a call for heat
from one zone. He told me it always worked this way and the upstairs
was miserably hot.
To me it seemed as though the 3 pumps and flo-control valves were a
botched add-on to zone the house.
I went over on Sunday and disconnected the pump on the inlet side of
the boiler and ran each zone separately. The system worked fine, only
got hot water in the zone that was calling, boiler reached temp and
shut down then restarted when it cooled off again. I verified that
each zone worked properly.
I'm going to leave the pump in place for a few weeks just in case a
problem comes up but everything seems OK. There is a little bit of hot
water creeping up the return side of a non-calling zone but it
shouldn't be a problem. The original threads can be read here if you