Hello all, I have a baseboard heating in one of my bathrooms that uses hot water. the covers are rusted up and I'm thinking of replacing them. however one side the fins stick out a little too much where I can't close the hinged end cap all the way. I would probably have to realighn the pipe on that side but am unsure of the proceedure. do I need to turn off the boiler or shut the water supply in some other way. do I drain the system? thanks