M
Masood
One thing I`ve seen on at least a couple of boards, is an earth wire attached to the pipework, then disappearing through a hole in the board so you cannot see where it goes and cannot check it. Is that a fault or a red herring? Also on one board, there was a rectangular metal plate behind the pipework. Is that an issue? Does pipework have to be a certain distance from unrelated metals?
Both those answers are in the books. We could tell you but then all we'd be doing is spoonfeeding you. I'd rather you did the research yourself, as in the process you'll learn other stuff too. It'll make you a more knowledgeable engineer in the long run.