Again woodbutcher, You seem to not be reading so good! Failure rates of about 20% were seen on the early models of the Wood Doctor gassers, They are belly up and I quit working with them when they buried their heads in the sand leaving many of my customers screwed, a lot has been learned over the past 5-6 years, Again you exagerate with moisture content of the wood, Gassers can burn greener wood as well but there is a learning curve, they simply need to have a decent load put on them when burning not so well seasoned wood and they also need to be kept clean, as any boiler, indoor, outdoor, gasser or non gasser, I burn very green oak at about 80% of my shows with absolutely no issues. Your idea of the clover leaf chimney cap is not a bad idea but it still does not solve the high stack temp issues of most conventional boilers, let me ask you a couple of questions, first, have you ever measured the exhaust temp(not the stack but actual exhaust temp )of your CB when it is running hard, I have measured several of them and will not post those temps here simply because I don't bash other peoples product. Second question, have you ever seen our B-L series units, they are very competitive in price to what you are currently running, burn much cleaner and BOAST an exhaust temp of 550 degrees F, sometimes price does reflect quality and design!