Since I am in the market for a 6-10,000 dollar boiler, (plus install), figured I'd get some input. I got on youtube and viewed many vendor and individual videos on 9 different advertised boilers, as well as a video on a homemade gasification barrel stove, and the only video (IMO) that had a "TRULY" blue flame was the barrell! All the boilers gasified, and one even had a slight blue tinge, but none seemed to have that nice blue flame, except the barrell! Why is that? Figure if anyone could coax that pretty blue flamefrom a boiler, it would be the vendors. I bring it up not to irritate, but to get information. The boiler that I am almost certain to buy also was lacking in the blue flame category! Comments?