I have been running my stove for about 14 hours and noticed a very lite tapping noise. It sounds like someone tapping on a piece of metal with a pencil very easy. It comes and goes and the stove seems to be working fine. I thought it was just the fact that the stove was warming up and the metal was just tinging like a hot water pipe would when your heat is turned on in your home but its been doing it all night. When I first fired the stove the other day for its first test run there was no noise at all. Everything on the stove seems to be working correctly. Any help please? thanks