Condensate hot water heating question

Andrew in Little Rhody

I need some help with a problem of banging pipes on my newly installed condensate hot water zone. I followed the piping tutorial & diagrams from this site ( excerpt from Dan's book) and I'm up and running. All is well until the zone shuts down ( stops calling for heat). My concern is my interpretation of the flow-control valve shown in the diagram of Dan's system (without the heat exchanger). I chose two Taco571 gold series valves one on the supply and one on the return. I think I've screwed up here, how does the hot water in the zone adjust pressure as it cools when the zone shuts down and both zone valves close.
Be gentle I'm a rookie.
Thanks
Andrew

Big Ed

Condensate Loop

In the set up you use flow valves not zone valves. The pressure will not adjust when isolated by the zone valves.......The banging could be the zone valve is shutting off before the circulator does.

Andrew in Little Rhody

Thanks for the help Big Ed.