Definitely needed this thread... I noticed with the Osburn 3500, if I've got a good fire going, I can kill the air 100% and still have a fire! I didn't expect that at all.
I've overheated a few times, and have just killed the air 100% and let it die down, thinking if I opened the air more, it'd get hotter yet.
I can normally "smell" overheating before anything else. It's hard to describe, but the other day when I got out of the shower, I immediately knew the wood stove downstairs needed to be choked out and yelled for my wife to kill the air. I don't know how to describe it, but steel gives off a certain smell when it gets too hot. My old wood furnace in the basement used to do it more frequently, and I noticed this one does too when it really gets going.
I'll be keeping a small bucket of sand nearby, great idea. Thanks for the tip.