Grandma bear sizing from 8"

  • Active since 1995, Hearth.com 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.

ThefirstLen

New Member
Oct 17, 2026
2
Surrey b.c. canada
I'm sorry if this has been discussed before, I'm new to the forum and wood stoves in general. We recently bought a property with a 2 story cabin on it ( about 1000sq feet). The stovepipe to the old wood stove was destroyed so we bought a 7" double walled pipe to replace it. We need to replace the actual stove now as it is beyond trashed. I was thinking of a grandma bear but I've heard a lot of conflicting things about whether it will be too much stove for our cabin and whether it would be a mistake to neck down the 8" collar to our 7" stovepipe.
I figured I would go to the people that actually have experience rather then Google and a.i.
I just want to be able to heat my place and maybe watch the fire for a bit in the evenings.
Any thoughts or advice would be greatly appreciated.
Cheers.
 
Will your cabin need a WETT inspection at some point in time? If so, it will fail unless your owners manual specifically addresses changing stovepipe/chimney diameters.

I had a 7” stove collar reduced to 6” chimney, the WETT inspector wouldn’t pass my install due to the fact that the stove wasn’t tested that way. Check your owner manual, I’d be willing to bet somewhere in the manual it will tell you to maintain the same diameter stove pipe throughout. Stove ran fine and lots of people use reducers/enlargers without any issues.

As far as overheating the cabin just build smaller fires.
 
No inspections needed, the property is out in the rural hinterlands. According to Google because the fisher stoves are built for a 8 inch Chimney, if I adapt it down to a 7 inch, it will no longer be able to vent all the smoke up the stovepipe if I leave stove doors open and the cabin will fill with smoke, that would be disappointing because I really enjoy getting to relax around the fire at the end of the day.