I have a Harman XXV which I purchased a few months ago. My home is a two story with a total of 3000 sq. ft. I know the XXV is probably a little under powered for this sq. ft. but I am trying to get some of the downstairs heat from the stove to travel upstairs. My downstairs furnace is not even on but still have to run my upstairs furnace since I can't get the heat upstairs. Any ideas?