zoned hot water system problem

RayV · 2006-11-01T18:58:48+00:00

My BIL has a problem with his system, here's the current setup:Boiler in basementSplit level house with all zone loops higher than basementThree zones - all thermostats working properlyCirculator pump on the cold/return side of boiler mounted just aboveboiler inlet comes on with furnace (zone independent)Flo-control valve on the hot/supply side of boiler mounted near ceilingAir separater right after main flo-control valve with bladder expansiontankThree additional zone circulator pumps connected to the thermostatrelaysThree zone flo-control valves, one right after each zone pumpThe problem is that whenever any zone calls for heat there is flow thruall three zones. I verified that each of the zone pumps are workingindependently and correctly. He told me that the system has alwaysoperated this way and he just sets the thermostat on the upper level to50 so it never kicks on because he always gets heat up there.There are no zone valves on any of the zones, only the flo-controlvalves. The zone pumps, flo-control valves and thermostats appear tobe add-ons to the original system.I would like to hear ideas on possible repairs or system changes thatwould get the system to only heat the zone(s) that is calling for heat.