I couple weeks ago I tried to start a fire after letting the stove go cold for several days. When I started the fire, it just would not take off, I tried opening the door a crack to give it a little air and it spilled a good amount of smoke every time. I tried opening windows and the front door to no avail. I let the stove go cold for the rest of the week and on Saturday swept the chimney but it was clean. Took the stove pipe apart in the house and guess what I found,a bird had decided to make a new home. Sucked out a foot of leaves and twigs with the shop vac. I hope this will save some of the new stove owners (like myself) time in diagnosing a future issue.