I bought a demo model boiler several years ago (4 yrs). Every year has been a struggle with the damned thing. Some were due to installer malfunction (me) and others have had to do with boiler design. The first coupla years I went thru 12-14 cords in one winter, in spite of the boiler supposedly being designed to burn less wood than conventionally designed boilers. I took care of that by re-routing the lines and insulating them alot better. Last year my wood wasn't nearly as dry as it could have been but I figured "Hey, they told me I can burn green wood." and yup, I can and I still used alot of wood without being really warm most of the winter. What the dealer failed to mention is the boiler is rated for 60,000 BTU/hr so it ran twice as long to get an equal amount of heat out of it because green wood will only produce about half as much heat per pound burned. This year I did things almost right. I cut and split 12 1/2 cords of mixed hardwood and had it stacked in the woodshed before winter. Up untill a coupla weeks ago things had been fine and I was feeling good, then the damned thing boiled over. Ran it almost dry and made a mess in the bldg I have it in. I replaced the aquastat with a new one and things seemd OK till this AM. It boiled over again. I don't know exactly what the problem is. I'll track it down eventually but its tricky because its an intermittant problem. I am really fed up with it. I don't mind making wood and the routine work involved with having a boiler but I expect the damned thing to be dependable. I'd like to hear from folks who actually have and are heating with an outdoor boiler. What kind is it? How do ya like it? How much space do you heat? Where are you located? How well is your bldg insulated? How much wood do you use in a heating season? What did you pay for it? Etc? Etc?