Please help me understand what you mean by "I just run my draft at .10" wc". How are you controlling your draft, and how are you measuring it? Do you use a damper in the flue? My understanding of the Blaze King stove (limited because I've never seen one operate), is that the only user control that affects draft is the thermostat. It's possible I've missed something or misunderstood.I run a king on a 7” flue. First 5’ or so is double wall black stove pipe the rest is insulated double wall. 7” is what was required for my previous stove. I rolled the dice on reusing it with the king. I have 26’ of flue total height with 2 45’s in it to go around the ridge beam. I just run my draft at .10”wc instead of .08 and have no issues...
From the manual:
"Recommended draft is .02 -.03 in. w.c. at medium fire and .05 in. on high burn. Too little draft results in a sluggish fire and smoke spillage when the stove door is opened. Too much draft (over 0.06 in. w.c. on high burn) makes it unsafe to operate the stove and will void manufacturers warranty."
I think we can assume the manual is referring to draft measurements on an 8" flue.
I'm sure your 26' flue contributes to your high draft, but since a 7" flue wouldn't move as much volume of air as an 8" at the same pressure, maybe the 7" flue needs that higher draft to get the proper volume of air. I'm just guessing here.
7" flue has 23% less volume per foot* than an 8" flue.
6" flue has 44% less volume per foot* than an 8" flue.
*I'm calling it volume per foot, but it's proportional to cross-sectional area. One radius squared divided by the other radius squared.
My 18' of 8" Class A chimney should be here in a few days, along with most of the other items I think I'll need for a proper installation, but there are a couple of other items that won't be here until December. I'm still considering trying the stove with my 6" chimney just to get a data point.
I appreciate your comments.