Boy you guys don't know how to have a good argument on here. You need to go over to ou power , those guy's can show how fight. All these boilers are rated for square footage and not btu's and this in itself give's them a way out. Just to many variables. If you go to their web site if I recall correctly the 4400 is rated for 5000 square feet, I have less than 2000 including the garage. The guy says why didn't I get the next size bigger, well with the horrendous amount of wood this thing burns I hate to think how much a bigger one would use. I tried to give a little background along with answering questions and I tried to be nice. But here is the thing, those here who are trying to fight me are on my terf. I was willing to lay my cards on the table I told every one my qualifications and I can prove them , when you challenge me tell every one what your background is in the piping, heating and boiler industry. Show me you have better qualifications than I do. Someone will say why don't you call a heating professional. Well [ duh ] that's like telling the cops why don't call the police? Or my personal favorite, see your dealer. Hey it ain't his fault he did his job, he is a salesman. I hold no malice toward the guy, in fact I like the guy. Why should he be held responsible for poorly designed equipment? But getting on here don't you think I haven't had other people look at it? all my friends are retired pros and they have all looked at it, my nephew who owns a pluming and heating service business looked at it. My nephew even put his electronic flow meter on it so we could prove flow and how much. Everybody that looks says the same thing, boy that a nice system' to which I reply yep sure is it just don't work.