I guess the title says it all, but do I need to damper down to get more heat/ secondary burnin a Jotul 550. It keeps the house at above 70 when full open and when I go to sleep I load a few large splits on and after 1/2 hour close the damper down to 1/3. I still have glowing coals in the morning but the glass is blackened, while during the day and full open damper the glass cleans itself. Ideas, this is of course my first season.