Ever since we hired someone to replace our old toilet for the 1.6 gallon toilet, we hear a bubbling noise in the wall when we flush the toilet especially in the morning and when water is filling up. It only happens in this bathroom. We are worried it could be a leaking pipe.Please help.

If you have a leaking pipe it would show on the floor by now. It could just be a fill valve that has a bit of debris. Call your installer and tell them you are doing a "call back" he'll know what that means.