I like the red handled Red/White ball valves, never had trouble with them. I wish they'd make iso flanges. I air tested a new system this afternoon and searched for awhile to find a leak and it was the iso flange at the silicone seal and no, I didn't over heat it. As my auto mechanic says, "Just because its new, doesn't mean its good"
When I installed my heat system a couple years ago I put in a couple 1 1/4" stubs on the copper manifold with ball valves for future. I recently found one of the valves with a small drip. It will eventually bleed my system done to 5 psi where the low pressure switch opens the circuits. I believe I used Nibco valves. Is there a better quality brand I can buy? I tried cracking the valve and reclosing with the B.F.P. feeding the system but it didn't help. Also I noticed some dark growth in the tubing on one of my floor loops. I am going to have to drain system to fix valve should I put in a growth inhibitor or cleaner of some type? Do you guys do that on a yearly basis? Thank you for responding.