Safety on wood stove install

  • 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.

velocity1

New Member
Dec 5, 2021
47
Connecticut
HI All,
Just had my hearthstone manchester stove hooked up and have some safety concerns. Im learning as i go and now that I have it hooked up one of my concerns was the heat being generated in the thimble through the wall to the tee connection. In one of the pics im attaching you can see the tee connection and the hole it runs through to my thimble, the length of pipe run from the tee to the thimble is about 2 feet. The 6" pipe you can see in the pics is very close to the clay lining which is about an inch thick. The chimney company used two straightened 90 degree pipes to connect to the tee to the thimble (the 90 degree pipes were adjustable so they could be straightened). They then used 2 90 degree adjustable stove pipes to connect to the back of the stove from the thimble.
My question is the would you feel comfortable running this stove when the pipe going through the clay lining to the tee connection is that narrow of a hole? Its single wall pipe going through to the tee. I do not know what is behind this brick wall and I also do not know how much heat will be generated on the other side of the clay lining? Does the clay lining absorb a lot of the heat or will it transfer through? Not knowing if there is any combustibles on the other side of the wall made me start thinking. Thanks

1.jpg 2.jpg 3.jpg IMG_5656.jpg IMG_5668.jpg
 

john26

Minister of Fire
Oct 27, 2008
764
Wildwood MO
I would not be happy with this setup. You should have an insulated liner running the length of the chimney. On the subject of the back to back 90's I would consider elevating the stove and run the chimney strait out the back or maybe to 45's?
 

velocity1

New Member
Dec 5, 2021
47
Connecticut
Thanks! The 20 feet of liner going up the chimney is all double lined, the only thing not double lined is the 2 feet of horizontal pipe connecting from the tee to the thimble. I was thinking of raising the stove, what do people usually use, just another piece of brick?
 

john26

Minister of Fire
Oct 27, 2008
764
Wildwood MO
I would use brick or a decorative concrete blocks to raise it.
he only thing not double lined is the 2 feet of horizontal pipe connecting
A longer t snout could fix that
 

velocity1

New Member
Dec 5, 2021
47
Connecticut
Good deal. As for the tightness of the hole through the wall, having the pipe so close to the clay liner is that concerning at all with how much heat is generated off the pipe?
 

john26

Minister of Fire
Oct 27, 2008
764
Wildwood MO
I would want it to be insulated especially in case of chimney fire the horizontal is where creosote will collect. Maybe one of the experts like Bholler will chime in.
 

velocity1

New Member
Dec 5, 2021
47
Connecticut
Ok thanks. Yeah was curious if that is also a concern with build up. Hopefully they chime in
 

tabner

Feeling the Heat
Jan 17, 2019
277
Eastern CT
i think it depends what is on the other side of / around the clay thimble. If that is a solid brick wall then you are fine. If it is framing around there, then it is not.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
29,102
central pa
Good deal. As for the tightness of the hole through the wall, having the pipe so close to the clay liner is that concerning at all with how much heat is generated off the pipe?
You need 12" of solid masonry all the way around that clay crock to make it safe. And the stainless needs to extend into the room. What you have probably isn't safe but it's hard to tell without being onsite
 

velocity1

New Member
Dec 5, 2021
47
Connecticut
Thanks All. The brick you see is a single layer of brick that is mortared to some type of wood backing. Behind that wood back im assuming probably insulation in the wall cavity but all guesses. I think it seems best thing to do is call the chimney company to come back and see if they have ideas on how to re-engineer the setup. I almost think they need to raise the thimble and make a bigger hole to get a double wall pipe through?
 

tabner

Feeling the Heat
Jan 17, 2019
277
Eastern CT
Thanks All. The brick you see is a single layer of brick that is mortared to some type of wood backing. Behind that wood back im assuming probably insulation in the wall cavity but all guesses. I think it seems best thing to do is call the chimney company to come back and see if they have ideas on how to re-engineer the setup. I almost think they need to raise the thimble and make a bigger hole to get a double wall pipe through?
That would be better. Bholler is the expert. But if the wall has wood studs in it, i think you actually need an insulated wall thimble, designed specifically for wall pass-throughs. Double wall wouldn't technically cut it.
 
  • Like
Reactions: velocity1

begreen

Mooderator
Staff member
Nov 18, 2005
94,486
South Puget Sound, WA
It's impossible to tell how safely this thimble was constructed, but the odds are it was not done properly. Also, the hearth is too shallow. There needs to be at least 16" of hearth in front of the stove and the side door locked unless there is also 16" of hearth on that side.

PS: Page 12 of the manual shows how this should be done if all masonry. It also shows alternatives.

Screen Shot 2021-12-22 at 8.54.51 AM.png
 

velocity1

New Member
Dec 5, 2021
47
Connecticut
The picture is a bit deceiving/warped but the side door I have 18" to the wall so i can easily open it with no interference. As for the hearth being too shallow this stove is in a mud room addition that is on a concrete slab. Basically its concrete and then the floor you see is actually tile so since the floor is non combustible would the shallowness of the hearth matter?
 
  • Like
Reactions: begreen

begreen

Mooderator
Staff member
Nov 18, 2005
94,486
South Puget Sound, WA
Basically its concrete and then the floor you see is actually tile so since the floor is non combustible would the shallowness of the hearth matter?
If the floor is non-combustible then you're good.
 
  • Like
Reactions: velocity1

velocity1

New Member
Dec 5, 2021
47
Connecticut
Considering how much I've already spent on what has been done I can only imagine the cost to re-engineer the setup. Hopefully its not too bad and luckily I didn't just move forward and run the stove as is, i rather have a house versus not spending a few more grand to prevent a disaster lol.
 

begreen

Mooderator
Staff member
Nov 18, 2005
94,486
South Puget Sound, WA
The clearance looks good. The camera is compressing distance to make it look closer than it actually is.
There are several ways to pass through a wall in a safe manner. The manual goes over several options. Here's an article on this topic:
 

velocity1

New Member
Dec 5, 2021
47
Connecticut
The clearance looks good. The camera is compressing distance to make it look closer than it actually is.
There are several ways to pass through a wall in a safe manner. The manual goes over several options. Here's an article on this topic:
Thank you, that article was very helpful!