Steam radiators extra loud lately and putting off a lot of extra steam?

My husband accidentally put too much water in the gas heater's water tank. There is a "maximum fill line", and he filled it the whole way. The water level hasn't gone down at all, but the heater is working, b/c its plenty warm in here. However, the pipes have been extra loud (clanking, sounds like someone banging metal) and they've let out a lot more steam than normal. Will they be ok? Should we be doing something to fix the situation, or will it fix itself?