Can't reach the cap to clean it but usually do a monthly pipe clean and get about a small coffee can full of dry stuff.Well it's been 2 months.Loaded the stove and let it get to 500 and closed it up.It was roaring as a big fire does.Nothing out of the ordinary.Sounded like it was drafting good.A fire roar bur not loud.Went outside and the underside of the cap was all hot coals and quarter sized chunks 1/4" thick of coaling glowing pieces were falling out of cap.Glowing went out in about 7 or 8 min's.Cap was dirty as hell last cleaning but pipe was super clean.Checked in stove and maybe a dozen corn flake size pieces were under the flue.No open flames out side and stove stayed under 500.I put sand on fire and opened door.Cooled down in about 5 mins.Did i just burn chit off cap or chimney fire? Damp roof thank god.No fault of the stove but maybe i left it open too long.Damned dry small wood on a hot coal bed. Put magnets on 2ndary intake just to make sure.