Expert: James Ball - 11/7/2008

Question
I have a two story home with a brick chimney. I have an existing oil burner. I would like to put an add on furnace that burns would or coal. I often hear that you can't exhaust solid fuel with liquid fuel out the same chimney. I would like to know if I could put class a metal piping up the existing brick chimney so that the exhaust for the two fuels would be separate. Oil out through the chimney and wood out through the class a pipe installed in the brick chimney.  Why not? the gasses would not mix or back flow since they are each contained in their own individual chimney.

Answer
Hello Ken, you are right you can not mix the two, they must be in separate flues, you can not install one pipe in a flue and let the other just go up around it. why not run 2 SS liners up the chimney (if you have room and sized properly)? I would have a local Certified Chimney Sweep (www.csia.org, there you can look up by zip code to find one near you) take a first hand look at what you have.
hope this helped
James Ball