I am at a loss for how to fix some problems with my radiator system. I have one radiator that always hammers. I have the radiator pitched back to the pipe and I have the pipe pitched back to the main. I have one that spits water all the time. I have the same scenario as above, however, I may have to fix the pitch back to the main. My third problem worries me more. My boiler is constantly going off on low water. Sometimes 2x a day. I have the main pitched back to the boiler, but it still happens. It seems that no matter what I try it still goes off, sometimes it goes off when the water is well above the low mark on the sight glass. I know the easiest thing would be to replace it, but what bothers me is that sometimes the water is below the low mark, yet I cant find water in the pipes, what happened? It did this on several occasions and I ended up flooding the system. I realize that means that it was in the pipe. I am at a loss and totally frustrated. Any help or suggestions would be appreciated.