I received my radiant manifold for my specific boiler which was ordered correctly based on the boiler. I did a dry test fit an found the flush valve fouls on the gas line. So I sent pictures showing this. I was told " we don't accept returns on installed items" Then when I said it was a dry test fit and here are images of the flush valve clearly showing the issue, They said we " sell these all day long and no one has complained, you probably didn't get the right one" Well I did get the right one. Now I am suck with figuring out a solution. I took the manifold off and decided to see what I could do, I removed the flush valve and as you can see from the photos, you could never had flushed the boiler anyway. The valve was clogged with pipe dope. So I checked the other one. Same issue. This is a 300$ part, that is poorly made with little to no quality control. If you go by their returns policy, you are stuck with it, or you will be paying a hefty price to return it, and if they decide it was installed, I am sure they will charge you a return postage fee. Oh look, I can't add pictures in the reviews even though it says, add pictures. DON'T BUY FROM THEM