Wood Doctor outdoor wood boiler. 500,000 BTU rated for 10,000 square foot. Model WD GS 70, decided to go with different heat source because of available time. Consider trade for Enclosed trailer , prefer tandem axel 14 to 16 foot but open to offers. Also consider fishing or pontoon boat , also consider loader tractor Available anytime, has been drained.can ad heat exchanger with right trade