I'm going to play dumb for a bit... I have a half-dozen changes or so to make to this boiler set-up based on input from others. I'm hoping for some feedback to confirm or deny. Not sure what is pertinent info yet, but we can get into that as you deem required. Thanks, Steven [URL="http://s262.photobucket.com/albums/ii98/stevensname/home%20improv/"]pics[/URL] (the exp tank has already been replaced ; ) )

The upstairs zone of my BBHW system has quite a bit of circulation after the zone valve closes (as long as the downstairs zone is still on). There are no check valves in the system and I am thinking I will need at least one or two. The zone piping is 1/2 inch copper, any ideas on what type of check valves will work? System Description: Gas fired boiler with a single circulator on the return. Two zones (one upstairs, one downstairs), each with two circuits (one in the front of the house, on for the back). The two circuits for each zone are "teed" back together just upstream of the zone valve and the zones are "teed" back together just upstream from the circulator. The unwanted circulation goes from the first circuit off the supply pipe and goes through the Tee back up the other circuit (reverse of normal flow) and back out to the supply pipe. I am thinking I will need a check valve in both circuits of the offending zone. FYI, I do not get any unwanted circulation in the downstairs zone even though there are no check valves in that zone either. Thanks in advance for the help!