My wife and I have been consumed with an odd banging sound lately...
We figured out it was coming from the chimney and only in the morning near dawn. So I turned off the heating system and it still happened, turned off water heater - still happend. Used no water - still happened. Left all the light off - still happened.
We just figured it out - a wood pecker is making love to our metal chimney. The sounding board effect spreads it through the whole house. Guess we have a new alarm clock.
Karl