Can't get an 8 in adapter to fit

  • Active since 1995, is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.


New Member
Nov 26, 2023
Andalusia, AL
We recently purchased a Fisher Grandpa Bear stove with a rear pipe. Our problem is we have been unable to get and 8 to 6 adapter to fit. We have tried an 8 inch to fit over the outside if the collar but is just a shade to small. An 8 inch with the crinkled edges (sorry, don't know the technical term) is to big to fit in. We are getting very frustrated and now have $35 in unusable parts. Any advice? The collar is 8 inches and we have a 6 in chimney liner.
You can normally slip a 8 inch Tee over the outlet pipe. Then cap bottom. This is stronger than an elbow, and gives you a clean out.

The crimped end is the male end. You go around it with hand crimpers making it smaller until it fits.

Using the search feature within this forum you will find many explanations how to connect to the older outlet pipe size that goes by 6 and 8 inch OD instead of the newer pipes used on stoves today that are made for stove pipe ID size. This was common on all makes and models back then. Search “crimper” posts by my username.

That said, it is against NFPA-211 and International Building Code to reduce smaller than appliance outlet. Many do, and depending on chimney and pipe configuration, may physically work fine.
If I remember correctly you can buy and 8” adapter to fit standard 8” pipe. This is the link: Amazon product ASIN B00186Y2DGIt’s called a double skirted adapter.
Also I remember reading sometimes reducing from 8” to 6” would not meet code. I’m not an expert though.