This could be it! I think, I've run out of options.
I haven't been totally idle in regard to "perfecting my system". As I said at the onset of this thread, my house is strange! Where you would expect heat to normally rise, mine goes down or "just disappears", to somewhere. ... I guess, it's in the house.
I played around with the fans, blowing in, blowing out, blowing across, sucking up, down and across. Nothing changed the outcome too much. Finally I got low on Pea coal, so put in a load of Nut. It looked "so-so" ... some was dull, some was about the size of Egg (Egg was a size available years ago), some was OK. It seemed to burn good, however I wasn't getting much ash. ??? Finally, I got a chunk stuck in the grates, so let it go out (during one of those cold days). What I found was, there were a bunch of large, hard pieces of ash, which just kind of rattled around in there, but wouldn't fall through or break up. As time progressed, their accumulation did, also. Since, I've been trying to catch the big pieces and break them up before burning them.
During those cold days the stove room, was in the area of 95*, with the ceiling above the stove at about 109*. So, I decided to put in a ceiling/floor register to the first floor. I came up with a 10" X 12" with ceiling grill, floor register and slip plenum, all in one package. I installed that and would you believe, you could barely feel any heat coming up to the first floor?!!
The stove room was still as warm as ever!
Finally, I broke down and fabricated a plenum with 6" pipe going through the ceiling grille. Now, I'm getting heat to the first floor!
The stove room is now running two to three degrees warmer than the middle area of the first floor. I can live with that.
I'll probably never know why this house is so hard to figure out. It might be, because it's on solid ledge and has a fair amount of water running under it.
I don't think, it uses a lot of heat, it is just unpredictable where it's going to go.