+1 on all of the above.......Usually will be a total roar, they dont just sit and smolder. The creosote/tars need a LOT of O2 movement to get HOT enough to actually burn. Best way to shut it down is to throw an 8 ounce glass of water on it and shut the door and air inlets.......the steam and lack of air puts it out........YES, and replace the pipe...........
Keep that puppy clean once a year, burn good wood, and perhaps a creosote "remover" once a week.........A good HOT fire once a day helps a lot to burn out accumulations......GOOD seasoned wood is the best though..........NO spruce, pine, alder, poplar....etc.......God bless......Dennis