Like Ed said, you either use circulators and flow controls or circulators
with zone valves and no flow controls. When you buy the boiler, it comes
with one circulator mounted on it, if you need more zones, you usually
remove that one and build or buy a manifold and mount them all together. So
you have a total of 4 zones, and I'm assuming 4 thermostats and relays. What
concerns me is what is controlling the boiler? Ed mentions an aquastat
maintaining his boiler temperature, some boilers maintain temperature and
some are wired for cold start, which means each zone control would turn on
its circulator and fire the boiler as well. What do you have for domestic
hot water? If it's a coil built into the boiler, you will have a triple
aquastat relay mounted on the boiler to maintain temperature, but if not,
you may have issues with the original circulator becoming energized when any
of the others come on.



"RayV" wrote in message
ups.com...
My BIL called me over to help him fix a leaking circulator pump on his
system which was an easy swap and fixed the leak. But he still has a
big problem with his system, here's the current setup:

Boiler in basement
Split level house with all zone loops higher than basement
Three zones - all thermostats working properly
Circulator pump on the cold/return side of boiler mounted just above
boiler inlet
comes on with furnace (zone independent)
Flo-control valve on the hot/supply side of boiler mounted near ceiling
Air separater right after main flo-control valve with bladder expansion
tank
Three additional zone circulator pumps connected to the thermostat
relays
Three zone flo-control valves, one right after each zone pump

The problem is that whenever any zone calls for heat there is flow thru
all three zones. I verified that each of the zone pumps are working
indepently and correctly. He told me that the system has always
operated this way and he just sets the thermostat on the upper level to
50 so it never kicks on because he always gets heat up there. On the
zone I changed the pump the flo-control valve stopped the water from
coming out when I pulled the pump. I'm assuming the other two
flo-control zone valves are also properly preventing back flow. But
the problem is they are are always allowing hot water to flow forward
even if the pump for that zone is off. There are no zone valves on any
of the zones, only the flo-contral valves. The zone pumps, flo-control
valves and thermostats appear to be add-ons to the original system.

Does this system need a circulator pump for each zone?
Should there be zone valves installed for each zone?