So here is the story. My MIL lives in rural VT by herself. Something is not right with her burning situation. She goes through 5-6 cord (75 years old). I have to clean her chimney 3 times during the season. She is running a VC defiant from 1980ish. The wood seems to be fairly dry (15% on a fresh split). From the temps that she running on the stove top and pipe she is running it a bit to low. But not that bad. Chimney about 18 feet. My thoughts/questions. Is that the correct chimney cap? Most of the creasote is built up on the cap. It is built up so much that it breaks off big pieces and falls on the room and ground. Can that stove be that ineffient that is is causing this build up? I wonder if the stove is working correctly. No one has done any work on it in 20years. It has a self adjusting air intake and the damper locks when the stove gets to a certain temp. Anyone have thoughts on this? Is it time to upgrade the stove? Chimney cap? Thanks