arnermd
Minister of Fire
I agree 1.1 iwc is extremely strong.... fortunately mine is only 0.11 iwc which I would consider to be typical (decimal places matter, lol #DPM)1.1" wc is strong draft, especially if that was measured with the key damper closed.
The stove will need to be in top condition with the door and ash pan gaskets sealing tightly. Check to confirm the primary air flapper is closing completely and not sticking.
Key damper was full open, air at 100% although I checked it with air full closed and it did not change, probably does not change much as the secondary flow path is wide open even with the flapper full closed.
You mentioned the air flapper, I did some work on it a few weeks back to make it seal better. But... if the flapper were leaking I would expect a robust primary burn, lots of yellow flames, that's not what I saw. The primary burn was nothing, no flames no glow and STT was very low, just a smokey, smoldering mess. To me that indicates no air leaks on the primary side anyway....
Installed a new metal cat today.... first burn was awesome, full load. Cat went to 1200 - 1250 peak with 50% air and hung in there for hours. Will post a plot tomorrow.