I am looking for any input concerning my 8yo Newmac oil wood comb furnace. When I use the oil, (which is rare) it heats the house fine. When I heat with wood, it struggles to get the house much over 60 if it is 20 or below outside. It is a big rambling farmhouse(3500sqft) with r38 wall insulation and mostly newer insulated windows. The fires that I burn are cranking hot hardwood fires. So hot that you cant get your face too close to the fire box. That hot fire does not translate into a warm house. I also go through 10 full cords per year (oct to april) I am pretty good with maintenance, dismantling and cleaning the angled steel chimney (6') that goes to the house chimney 2 to 3 times per year. I also scrape the soot that accumulates around the plenum, and change the air filters yearly. Any suggestions to improve this situation would be appreciated.