Wanting to get a new stove and need help with deciding what to do about my current chimney/flue set up.

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New Member
Apr 28, 2022
Hi all, new to these forums and in need of some advice.

A little over a year ago I bought a house with an old wood burning stove. I'm guessing the thing is original to the house which was built in 1976. I have no knowledge of how often the flue has been inspected, or cleaned, but I think it's been somewhat maintained, because I've cleaned it a couple of times and the creosote buildup didn't seem to be too bad. I've been trying to find someone who does chimney inspections in my area who can look at the condition of my flue and see how it's doing (especially since the pipe could be around 40 years old). Unfortunately, I have not been able to find anyone even close to my area (Green River, Wyoming), or anyone willing to drive here. I've read online that most steel chimneys should be replaced after 15 - 20 years. I'm guessing I'm well beyond that.

So I'm wondering if I should consider replacing my old flue system? If yes, how hard of a DIY project would it be since I can't find anyone in my area that does this type of stuff? My flue system is a straight shot up, with the stove on the second floor, the flue passes through the attic and then exits the roof (probably a total of ~20ft). I'm fairly handy, and very meticulous with checking on building codes and following them.

To complicate matters, my wife and I are looking into getting a new wood stove to use as a primary heat source for the house (with a gas furnace as a backup heater). The problem is, I have an 8" flue and the stoves that fit an 8" flue are probably too big for the area I need to heat (about 1,800 sq. ft.). It seems that most modern fireplaces that would work best for our house have a 6" flue. I don't want to use a reducer, due to the issues with draft that I've read about. If I end up replacing the entire flue system, is it difficult to go down to a smaller size (an 8" down to a 6"), or should I really stick with the 8" and get a larger stove than I probably need? I'm guessing the primary challenge would be needing to patch the roof and then recut the hole for a 6" setup? Anyone know any good books or anything to help with this type of project?

So to summarize my questions:
-Since I don't have someone that can inspect my flue system, is there something I can do to get a good idea of the condition of the flue?
-If I need to replace the whole flue system, how hard of a DIY project is it?
-If I do a replacement, should I stick with an 8" stove to keep things simple, or should I go to a 6" stove and put in a 6" flue system?

Any help you can provide would be GREATLY appreciated! Thanks,


Staff member
Nov 18, 2005
South Puget Sound, WA
First the system condition needs to be checked. The odds are that the chimney will need to be replaced if 40 yrs old. It may not be up to current HT2100 standards for class A chimney unless it went in or was replaced in less than the 40 yrs. Do you know what the OD is of the chimney pipe? If it's 12" the pipe is probably triple wall and not up to standard.

If replacing, I recommend going with 6". It is the most common size. The installation is not that complicated for replacement. Patching the roof may be the biggest part. Do you know what stove will be going in? A modern stove would probably draft ok on 8" given the setup if it passed inspection and the points made above.