How do one "remove" debris from water heater pipes so there is running water in the hot lines?
Thank you

They only debris in a hot water pipe is usually the nipple(S) on the hot water heater that gets clogged.

If there's old galvanized pipe there that would have to be replaced if they are badly corroded inside the pipe.

If you have a domestic coil in a boiler that can get clogged and may need acid washed or replaced