Chimney height questions

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Rob_Red

Feeling the Heat
Feb 2, 2021
289
Southern New England
First question, I’m installing a through the wall class A setup for my hearthstone GM40. The manual doesn’t have much info on chimney specs. Does chimney height include my stove connector pipe? Or does it start where my class A starts?

Second question, I have six 48 inch sections….using 5 sections will get me 2-10-3 rule compliant. However Will 20 feet of class A be a proper height for a 90 coming off the stove, an 18’ piece going through the wall, and a T with clean out?

Or should I throw the sixth 48’ section on and exceed the 2-10-3 rule but get a potentially better drafting chimney?

Or should I exchange the unused piece for a shorter length and run that?

Let me know if I’m over thinking it!
 

Highbeam

Minister of Fire
Dec 28, 2006
19,154
Mt. Rainier Foothills, WA
With the problems people have been having I would opt for extra height for stronger draft plus a key damper now or later if you need to reign it in.
 
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Rob_Red

Feeling the Heat
Feb 2, 2021
289
Southern New England
Another bit of info… the old chimney was about the same height as I would get with my Five 48’ sections. It was a cracked up clay lined cement block build and it actually drafted just fine. I haven’t had any of the previously mentioned Green Mountain issues.

I didn’t have any operational issues with the stove with the old setup (just a really out of code chimney)

I’m maybe 30- 50 feet above sea level, and I’m up on a hill with nothing impeding the wind.
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,584
South Puget Sound, WA
The vertical gain of the stovepipe is included in the overall flue system height. So if there is 4 ft of stovepipe before the 90 then I'd probably try it out with the 20' of chimney and see how it drafts in say 40º October weather. If good, then it will be great below freezing.
 
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