First time poster. Love the forum, its been very informative.

I installed a radiant floor heating system and it has been running flawlessly for the past 5 years except for one thing: I've been having a number of problems with main check valve; the one that forces incoming supply water to circulate through the floor tubing zones before entering the water heater/boiler. The current check valve is a 1-1/4" brass swing gate style. This is the second one. The first one was part of the kit I bought and it ultimately failed when it developed some pinhole leaks and build-up of calcium which I had to regularly clean. The second one is also having the same calcium build-up. Now, mind you, this is with post-softened water with less than 1 grain of hardness; and I know that I need to fine tune my softener system to get that lower but it is what it is, for now.

I have found several threads on this site and others that discuss these types of radiant systems and it was mentioned that a HIGH QUALITY check valve be installed in this location, I assume to prevent the issues I'm having now; and one thread that had a broken link to an exact product.

So my question is what type of check valve should I purchase and install? Brass? Stainless Steel? Swing gate? Spring loaded? Teflon seals? Etc... Also, would this quality check valve really help me with the calcium build-up over the one I currently have?

Thanks in advance.