After warping my stove insert and melting the SS liner trying to heat a large house with an undersided stove I am thinking that a properly sized wood furnace or boiler might be a better option. I am looking for the users here to weigh in on the two options for my particular case. -Install would be in a basement, flue would be right around 40' -Total winter heat usage is right about 130 MBTU per year averaged over a 4 year window -Storage for a boiler is not likely unless it can fit down a steep set of cellar stairs and through a 32" wide door -The house has a forced air HVAC system -I am slowly working on putting in a hydronic system, staple up under floor radiant heat and I am putting in a water chiller system hooked up to water-air coils on the air handlers for AC. There are 3 air handlers currently with a 4th one possible in the future -House is 3500 sq/ft, solid uninsulated masrony walls with an insulated attic, and about 130 years old -I have natural gas and its cheap, I don't mind having the gas furnaces kick on for make-up heat. -Current output of the gas furnaces (there are two) is 160k BTU and they have kept up on the coldest days -If a boiler, it would be used for space heating only. DHW is cheap enough to come by with natural gas. -I have hopes some day of a solar hot water system to supplement space heating, but it may never happen. -If I go with the boiler I would likely replace the gas furnaces with with simple blower cabinets and get a mod-con boiler My concerns: -Due to the draft from a long flue my insert was very hard to control to the point that I warped the top and melted the liner from constant over-firing. I am worried I will have the same problem with a furnace or boiler -The lack of any signifigant storage for a boiler will cause a lot of start/stop -Same start/stop concerns for a wood furnace -Cost of a gassifier boiler -I am in an urban area, whatever goes in will need to have minimal smoke. My EPA secondary burn stove did just fine in this regard for a point of reference The house is old and the design and the way it is built does not lend itself to a single central air system without a huge number of bulkheads and other visually intrusive construction to hide ductwork. It has a 15x15' two story open entry room so air stratification is also a huge problem. Having 3-4 smaller air handlers with a central water chiller and central boiler running water to air coils is signifigantly cheaper then 3-4 seperate gas furnaces and AC units. So, furnace or boiler or say screw it and go back to natural gas?