Plumbing my boiler (AA 130) --loops and valves.

I have an AA 130 and I am hooking it up to a forced air furnace with a heat exchanger but am also planning on setting up zones for future radiant floor heat and some baseboard hydronic heat. I have been reading Holohan's 1998 book, Hydronic Radiant Heating and I am learning. I have never installed a system like this before.

Here are a couple of questions:

1) Are flow control valves necessary after each circulator? I was under the impression that newer circulators would suffice to prevent gravity circulation in the zone when the circulator is shut off. Is this the case?

2) Is primary/secondary looping always the way to go?

I have some other questions about some of the controls, but I thought that I should post them in the "controls" section. I will probably have a lot more questions about everything actually! Bear with me...I'm new at this!

Thanks for the input!

Mark

Hi Mark, if you buy circulators that are 'IFC' versions [internal flow check] then you don't need to add externa flow checks.

Primary/secondary plumbing is usually a better way, but 'it depends' on many variables. Series setups have worked for centuries.

Greg L

As Greg put it......... I myself did lots and lots of reading/studying on different ways of plumbing my system. There is a science behind it all. I chose the Primary/secondary system, and am very happy with it. If I had to do it over, I'd choose the exact same set-up. I did hire a HVAC friend of mine to help move the project along (another good move). At first, I had no check valves in my circulators. The system was whisper quiet, but had ghost flow. After installing check valves in the circulators, performance was much better but, when ever a circulator runs, I can hear the check valve rattle in that circulator. Not terribly bad, just noticeable. The more circulators running, the more rattle noise. Of course, my office is directly above my system. The only place I can hear the rattle is in the office. The rest of the house is still whisper quiet. I do believe if I would have dropped the secondary return lines about 20" below the closely spaced "T's", and then back up to the "T", I could have gotten away with no check valves. The whole system would have been whisper quiet, and no check valves to go bad. My HVAC friend frowned upon doing that. I don't think he liked how it would have looked. All and all, I'm very happy. I don't know as if you need to go with a primary secondary system. Then again, the primamry loop acts as a bypass loop, whick KEYSTOKER recommends installing with thier boilers. Another recommendation would be to add extra take offs in the primary loop for any possible future secondary loops. Oliver