I have been heating my DHW, 140 year old 2200' Home and 48,000 cubic foot insulated shop now since the second week of September. I have been dumping heat at times just to make sure I have a maximum time of 10-12 hours. I have three 200' floor joist loops, exchanger in oil furnace plegnum and cast iron radiator in great room. I have had rad shut off and the radiant floor heat is heating the entire house. I think the fan in the furnace has only come on when it is 2'C or less. We have had to keep windows upstairs open a crack to let the heat out. Much of this heat is coming from the basement up the vents and returns. The basement is a sauna as I have 3" sprayed insulation on the walls.
My shop is kept at 21'C with a 100,000 BTU Dragons breath exchanger unit. It was -2 at 6AM when I went outside and the shop was steady at 21 and the fan wasn't calling for heat.
The boiler is set at 170/180 and was 183 when I woke up this morning and just starting an idle cycle. I have a wireless meat thermometer with 2 zones and the temp differential to return was 183/176 and have just shy of 200' of Logstor to the boiler.
As far as wood consumption goes it is tough to gauge right now as I am burning wood from different stacks. My best guess would be about 1.5 cords of mixed crap. On milder days dry pine and very poor quality woods. On the colder days I throw in a chunk of walnut or maple at night for longer burns.
Very happy with the results. I have pulled blower off the back of my unit and there is no creosote buildup or flap issues at this point that I have read about.
Very happy!