Multiple Zones heating from one thermostat

PRC

I have a four zone (3 heating and one hot water tank) system, each has circulator pumps (this was recommned by the installer instead of one circulator with valves).  I have two zones upstairs and one in the basement.  When I turn on one of the zones upstairs, both come on. I do not know if I have integral fl-checks in the circulators, but do not have any external ones.  I did some on-line research and it seems like this might be the issue.  However, a friend of mine who knows "a little" about heating said the flow checks would only be the issue if I were running multiple zones off of one circulator. Is this true and, if so, any ideas what my problem might be?

Alan (California Radiant) Forbes

You said,

" When I turn on one of the zones upstairs, both come on..."  Do you mean both pumps come on or one pump comes on and you're getting flow through the other zone with the pump off?  If the latter, you can certainly get "phantom flow" or "ghost flow" through that circulator.  I'd say you would need a check valve on the supply and maybe even the return.



I'd call the installer back.  If he recommended pumps, he should have know that check valves are required.

Alan (California Radiant) Forbes

Also,

take a look at the model number of the circulator.  It might tell you that there is an integral flow check in the pump volute and if so, maybe it has failed.



Taco uses "IFC" for integral flow check.  I don't know what Grundfos does.

PRC

IFCs

I believe it's just "ghost flow"... but it's more than "some" it's as if the whole zone is on.  I feel like the installer probably is not as good as I thought... he was recommneded by a friend, but I've asked him about the issue and he seems stumped.

I do have a taco cartridge circulqtors that can come with IFC, but these don't.  I believe they are fit so I can buy some to drop in, but I am confused by your suggestion that I might need a check valve on both sides... if I get the IFCs is that enough?

Thanks!

PRC

IFCs

I believe it's just "ghost flow"... but it's more than "some" it's as if the whole zone is on.  I feel like the installer probably is not as good as I thought... he was recommneded by a friend, but I've asked him about the issue and he seems stumped.

I do have a taco cartridge circulqtors that can come with IFC, but these don't.  I believe they are fit so I can buy some to drop in, but I am confused by your suggestion that I might need a check valve on both sides... if I get the IFCs is that enough?

Thanks!