a separate flow check valve or a circulator integrated with a flow check valve?

heatingFun

which way is better for adding a new zone in a hot water heating system, a separate flow check valve + a regular circulator or a circulator with a built in flow check valve?

Zman

Check

The integrated checks are "spring checks" and are similar in design to most flow checks. They appear to be less robust. That being said I have had very few problems with them and the don't appear to increase the cost of the pump.

Jean-David Beyer

As a homeowner ...

I have a hydronic heating system with two heating zones and another "zone" for the indirect hot water heater. The hot water heater is across the supply and return from the boiler, but the two heating zones are in the secondary circuit of a primary-secondary setup. There is a boiler circulator in the primary loop that runs if either heating zone is being used. Otherwise, the circulator for the indirect is the only one being used. The boiler circulator is a plain Taco 007. The other circuators are 007-IFC. In the boiler loop is a real flow check in the supply line going to the two closely spaced Ts.



The spring checks in the 007-IFC protect against reverse flow through the circulators that have them. It is my impression that the springs in the IFCs are intentionally weak, and do not protect against flow due to convection. In my system, I do not need protection from that because the piping layout heat traps those circuits. The hot water would have to drop over 5 feet to cause any flow.



There is a real Flow Check valve in the supply line in the primary loop leading to the closely spaced Ts mainly because the manufacturer of my boiler specifies it. It certainly does no harm. I think it is to prevent hot water from entering the secondary loop because of convection when the indirect is calling for heat. It is true that I would not want heat doing that, but it seems to me that in that case, there would be no flow in the secondary loop, so it would not matter. But I have not studied it enough to be sure, and I suppose my manufacturer has studied it. So I leave it in.



So your question seems to depend on whether your piping is such that you do not need a real flow check valve.  If your layout is such that it heat traps so you do not get convectional flow, the integrated flow checks will suffice. Otherwise you need real ones.

mikearmorplumbing

check

a circ with intergrated flow check is the same as a circ with a seperate flow check...go with whatever is cost effieciant...just my oppinion