I have managed to heat my old 1500 sq ft house + 1000sq ft garage so far this year with just a blaze king classic. It is -44 right now and I just heard the boiler fire. Bummer. I think I will be O.K. but I was so proud telling people I was burning no fuel in North Pole alaska. O-well. Mabey I will put another stove in the gagage.