Best explanation of how hot water heating works is right here on this PDF by Bell and Gossett.
They walk you through it all.
http://www.bellgossett.com/BG-Literature-Detail.asp?LiteratureID=1195
Hydronics, not hydroponics 
Opps typo.
And you can not edit these titles damn it.:shock:
Please let this thread die------Please let this thread die------Please let this thread die.
Not every day I get to pray for death.
Thanks Kondo Bob, nise fynd!!
I was wondering why you would type that…
But that is good info.
Ignore this thread and go to the other.(bump) oooops.