Odd sounds: Scraping or fluttering noises coming in the chimney could possibly suggest an animal nesting inside of, that is a common reason for blockages and should be taken off professionally. Make sure you use a thin hose attachment to extend the vacuum into The underside with the housing cavity. https://www.google.com/maps/d/edit?mid=1ivrVRAiAZOS6JnCCEiaC_34ZZpQtk3E&usp=sharing