061031 0950 - Edwin Pawlowski posted:


"RayV" wrote in message

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)

Why? You have three zone valves and three circulators. The individual
circulator for the zone should be doing the ork.


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.

Was this a single zone system that was converted to a multi-zone system?
Sounds crazy to have a main circulator plus the individual zones. Could
also be the zone valves are not operating properly. Have you checked to be
sure they are closed?
.

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

Should be one way or the other. Any thermostat calling for heat would start
the pump and open the valve for that zone. My house has two pumps, one for
each zone. The thermostat starts the pump for that zone only and heats
that zone only. The boiler is controlled by an aquastat that starts the
burner when the water temperature gets below the set point.


I don't understand the multiple circulating pumps. If there is a manifold
with zone valves, when a zone thermostat calls for heat, the zone valve will
open, and that turns on the circulating pump. Only that zone will get the
hot water. The same for the other zone. The circulating pump won't shut
off until all the zone valves are closed.