Grandma bear sizing from 8"

[ThefirstLen]

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.

 

[Murray01]

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.

 

[ThefirstLen]

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.

 

[begreen]

It sounds like the flue system will have about 25' of height. Is that about right? Will the flue be interior and straight up through the roof or exterior with a couple of 90º turns in the smoke path? If interior and straight up, then it may draft strongly enough once it has had a chance to warm up.

 

[ThefirstLen]

18 feet straight up through the roof

 

[EatenByLimestone]

I imagine it’d be fine with a small fire and doors closed. Open doors and you may need more room to exhaust the incoming air.

 

[ThefirstLen]

Yeah that was kind of my fear, I go through the process of moving the stove up to the property and in place and get smoked out the first time I decide to leave the doors open.

 

[EatenByLimestone]

Well, you’ll get a reminder to close them!

 

[AKDoug]

I'm in a non inspection area and we took the gamble to try a GrandMa Bear rear exit for free while constructing a small house. Due to tight restrictions as to where the pipe could possibly run, we could not use a 8" insulated pipe and had to use 6". This was fine because it's our full intention to upgrade to a modern stove with a 6" flue next season. We gave it a shot and are amazed at how well the stove works with the reduction. We haven't shut it off in over a month and have had almost zero issues. You will get a little smoke out the front if you open the doors rapidly if you open them on a damped down fire. If it's roaring, not smoke issues at all. We are 22' straight up on the flue.