I have a check valve in my system that is wicked noisy occasionally. It seems the faster I run the circulator the higher chance it will make noise. I say it like that because some times its quiet when on medium or high speed and other times it's very noisy. See the below check valve circles in the diagram. For example, none of the zones are calling for heat, boiler jacket is 180F so it's only load is to charge my Solartechnics tank. I have to shift the circulator into medium or high speed to keep the boiler from entering idle mode when the top tank temp is nearing 170F. I can run it in high speed for a while and no noise then all sudden the check seems to start chattering. Any ideas? I know the placement of it is likely the cause because the Tee is probably causing turbulence. If I could somehow get the air out of the top of the check valve would it help?