Hey Don! I applaud your efforts. I'm sort of cracking up too
You have way too much time on your hands. My first question would be,,, was your coal from the Yellow flame totally burned? Was your boiler insulated? Did you adjust the yellow flame to a lower setting? Why would you change out a unit in the name of efficiency that was capable of burning Barley sized coal? Did you clean the inside surfaces of your boiler periodically last season? Did you burn more coal last season than you should have like the rest of us? I'm sorry for the guff but based on the experience I had last season with the same boiler as yours, I don't understand why you would want to change a beautiful piece of Machinery.
1) The coal was not totally burned. On warm days it seemed like the ash was mostly partialy burned and black. on cold days there was still a lot of black.
2) No, I do not have the boiler insulated, maybe I should.
3) I did every kind of adjustment I could think of. I even made a second combustion blower choke piece so I could realy lower the combustion air, still lots of black in the ashes and 80 to 110 pounds of coal a day.
4) I agree, The Yellow Flame stoker is a great machine, it will take more than a lifetime to ware one out. I would have liked to try the Barley option but, down here in the south there is no one that supplies it. I could go up and get it myself but, when you factor in the $80 for gas and the 5 hour round trip to get 1 3/4 ton in my truck, it is not worth it.
5) I only did one boiler cleaning. I didn't get it fired until Jan 20 and it wasn't heating the house until early Feb.
6) I burned a LOT more coal last winter than I ever have. I would normaly burn about 3.5 ton in the Harman SF3500 per year. last winter I burned 6 ton but, that could have a lot to do with the fact that I changed heating systems twice last winter, Harman SF3500 to Alaska 140 to Yellow Flame.
7) Scott, I don't know, maybe I'm crazy, I want to see what this little burner will do in there. I didn't like seeing all that partialy burnt black coal in my ash last winter.
If it doesn't work out I will just throw the YF back in there. I will be putting up an 8 inch id stainles chimney to replace the 6 inch chimney, maybe that is part of the problem?
I also have plumbing pipe size questions I will ask later. It is possible I am not getting all the heat to my heat exchanger.