Chimney maximum height?

Thats exactly where chimney fires originate, Most creosote formation is in the last third of the chimney pipe.
Your sugestion on having the damper up top is a good one, if i were to put one in thats where i would put it. I still wouldnt recomend it, based on the manufacture says its a no no, even though the dealer says its ok, in the case that there is a problem it will be up to the dealerto fix it with no manufacture support. That usually doesnt go over very well.

They usually don't originate there, BB, but the ones I've seen start at the firebox and work their way up the stack until they eventually hit the creosote motherlode. Then you see some sparks fly.

BTW, just as a point of information, I have an 8" damper on my boiler which I use all the time, but it's located before the cleanout tee so that it's not in the way when the time comes to run a brush up the stack.

Thanks for clarifying that Eric, i knew that the top third had something to do with it!

What about a motorized damper top or bottom controledby motor opening x amount many oil burners have them ina 6" connector pipe

What is the inside diameter of your chimney? Does it have a clay liner already inside in good shape? What about a direct connect? Since you have such a tall chimney any stove may draft good even if the chimney diameter is larger than the stoves flue collar?

I have a clay flue liner that has a 9 1/4" x 12 1/2" inside diameter. It's a newer house, and the flue is in perfect shape.

Ask your dealer if that size flue meets the maximum diameter flue size for the stove you are looking at. A direct connect to the flue may work, since the chimney is so tall. And It would save alot of money.

Code wise the only direct connect to that size chimney that has a chance of working is from an 8" flue collar
if an outside exposed chimney evenit is too large for even *" inter chimney code wise it would be ok
You must have a rather large fire place opening, for the mason to have used a modular clay liner, instead of the conventional 12 /12

The croos-sectionar area of that flue is more than 200% larger than code will allow for a 6" flue collar

There is another way to look at it besides stove specs look at the liner manufacture's specs What if you used 6.5" diameter liner would that add to the supported height? The stove manufacture claim a height according to using 6" but what if 6.5 is used and the height is supported by the liner manufacturer. Check out liner manufacture's specs . Is there any way you can place an in line damper in the connector pipe if needed?