So I'm curious, when you say "run over a 7" do you mean heat soaking the wood for the first hit, or second or third hit? On the first hit, I'd say that squares with my unit (I soak at 6.2-6.5 during day), over 7 and I risk combustion without minimal glass heat soak and fast inhale. However, for the second, and third, I can run up to 9-10, if I just stir and go immediately after finishing the first. Do others have this same experience? I go right back down to 6.5 when I'm done to get ready for the next session. I have combusted heat soaking the wood at over 7.5 (i believe) at around 80F (room temp, no drafts, fans, or AC) for at least a few hours. I mean really lit on fire, not just made black ABV. I don't really consider this a defect though, in and of itself. Certain strains and moisture levels, as well as concentrates (more so) need the higher heats. I was actually surprised, the biggest clouds I blew with my nano was not with the most resinous strain, but with some moist product I got. I definitely get "charring" though, all the time, if you mean some black ABV, even at 6.2 heat soak for initial hit.