I think this was a mistake by the builder. I am on city water so it's not the old hard water trick. Steaming hot water is not so fun to drink when you're looking for cold. So I need to move the line to the cold pipe. The fridge line is much smaller of course, so it is currently attached with a kind of T joint tap to the hot water pipe extending from the boiler. What is this properly called? I'm assuming underneath all that there is a hole drilled in the copper pipe. I will have to take that assembly off and move it to the cold pipe. So my question is what should I use to patch the hole? And for drilling a new hole in the cold pipe, what kind of drill bit should I use? Or am I way off here? Thanks!