Yes, it is normal for the flame broiler to rust and deform slightly due to the high heat and oxidation applied to it. You should not use water to clean a flame broiler, otherwise, it will cause rust to grow rapidly. We put a lot of emphasis on cleaning the grill but the flame broiler plate is a bit low. Grease and smoke build up on the flame broiler plate over time, which protects it from rust, so we don't tell it to be super clean. The best way to clean a flame broiler is to either scrape it with a putty knife or use a slide cover to move the debris back and forth.