Fireplaces, Heating Stoves, Flues and Chimneys - Venting a pellet stove up an existing chimney

I currently have a Coalbrookedale Darby woodburning stove in my home's first floor "greatroom". It's on a brick hearth on an inside wall and the stove is vented up through the middle of our two story home through a class A 8 inch diameter chimney. It's about 25 feet from the stoves flue to the top of the Chimney. I'd like to replace the Darrby with a pellet stove and I am wondering if I can use my existing 8 inch chinmey (as is or with modifications) as the exhaust chimney for a pellet stove. Anyone have any experience doing this? Any advice?

Check the installation instructions for the new pellet stove to see if the set up you have is recommended. Too, you might want to check with local building codes. Sometimes these supercede manufacturer's recommendations.