If your galvanized hot water line is blocked, there is nothing else you can do that is legal and safe for the drinking water. There's all kind of stories about unsafe methods, but the only water safe, sanitary, and healthy method, is to replace it.

I've only got an opinion mind you, but my opinion is based upon 4 years as an apprentice, 5 years as a journeyman, 10 years as a master, 5 years as a project manager, 3 years as a general manager and 5 years as a professor of plumbing.

Raymond VinZant Plumbing Prof.