Replace ZC fireplace with free-standing, wood-burning stove

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ATX_stove_wanter

New Member
Apr 26, 2021
2
Austin, TX
Hello all! Long-time lurker, first time poster.

I've been browsing this forum for a while for ideas and education while this project idea has been turning in my head. I've been blown away by the community on this forum and everyone's willingness to share their knowledge and experiences in order to help people achieve beautiful and most importantly, safe results.

I live in Central Texas, so our winters are fairly mild with few truly cold days. But this past February's winter storm, along with the new IRS tax credit, has given me a little motivation to finally move forward on this project above and beyond just loving the ambiance that a fire gives, and the aesthetic of a free-standing wood-burning stove.

Present State
  • 1984 construction on concrete slab, approx. 1470 square feet
  • Living room features a builder-grade TrueHeat TH-36 Zero-Clearance fireplace that I believe must be original to the house.
    • I have attached the PDF installation manual for this unit to this message
    • The fireplace has a natural gas attachment (you can see the key behind the guitar in the interior picture)
    • It appears that there is a vent on the side of the chase, perhaps for external venting per the install manual?
    • Per the install manual: "Never use fireplace inserts or retrofit your Trueheat* fireplace with a wood stove and/or stove pipe." so this avenue is closed to me.
  • The fireplace is flush to the wall, and sits in an external masonry-faced bump-out/chase (see pictures) on the slab.
    • This chase has the following external dimensions:
    • 66.5” Wide
    • 24.5” Deep
    • 11” and 10.5” from the outside of chase to the left and right-hand windows, respectively
    • The ceiling height throughout the house is 105"
  • Given the above figures, my suspicion is (without having opened the walls) that with the ~3” depth of the brick, another ~3.5” for the framing 2x4, plus .5” on each side for interior cement board, the interior size of the alcove would be (max, with slightly greater distance-to-combustibles) :
    • ~52” wide
    • ~22” deep
  • As you can see, the exterior chase itself is quite tall. I’m not sure how this impacts the install or what additional work would be necessary to accommodate this.
  • Since the external bump-out/chase is masonry, I do not have reasonable access to the back of it (I have read this is necessary for newer ZC fireplaces, but I am not sure why)
Photos

IMG_1135.jpg IMG_1136.jpg IMG_1138.jpg
Desired Future State/Goals
  • A free-standing wood stove installed in the alcove described above
  • A stove that can heat the front of the house (~15x20 living room, and the 10x20 dining room behind it (they are connected with a pony wall between).
    • My expectations are not that the entire house be heated.
  • The stove is eligible for the new IRS tax rebate
  • I am completely OK with the alcove being full ceiling-height (I do not care about a mantlepiece/hanging pictures etc)
  • A raised hearth would be nice though certainly not necessary
What I have done
  • Visited what seems to be the lone fireplace/stove retailer in my area. I described my issue and showed pictures. They said that without the measurements of the chase, they were unable to recommend a route forward. Understandable!
  • Educated myself on the basics such as clearance, distance to combustibles
  • Put together a library of threads from this forum featuring similar projects, etc. Some are close, but I do seem to have some unique particulars.
Questions
  • What are some suitable next steps for my situation?
  • What aspects of the purchase/install does the IRS tax rebate cover? I assume not the demolition and removal of the old stove/alcove.
  • Is there a short list of recommended stoves that meet the requirements of the alcove size and that satisfy the requirements of the new tax rebate?
  • What, if any, additional complications will the long chimney length introduce to the project? One thread featuring a similar project (albeit with a multi-story house) indicated some difficulties with chimney installation, and the same individual encountered issues with condensationas well.
    • For demolition?
    • For construction?
  • How will the gas line running to the current stove complicate demolition and construction?
  • Would installing a new EPA-compliant ZC fireplace be a superior route in my situation, or would it require external access through the back of the chase (not practicable, obviously!)
  • What additional important questions have I not asked?
Thank you for any help or guidance anyone can offer for this project. As you can imagine, for anything dealing with fire, safety is my first and most important consideration.
 

Attachments

  • th36.pdf
    2.4 MB · Views: 71
Last edited:

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,670
central pa
Hello all! Long-time lurker, first time poster.

I've been browsing this forum for a while for ideas and education while this project idea has been turning in my head. I've been blown away by the community on this forum and everyone's willingness to share their knowledge and experiences in order to help people achieve beautiful and most importantly, safe results.

I live in Central Texas, so our winters are fairly mild with few truly cold days. But this past February's winter storm, along with the new IRS tax credit, has given me a little motivation to finally move forward on this project above and beyond just loving the ambiance that a fire gives, and the aesthetic of a free-standing wood-burning stove.

Present State
  • 1984 construction on concrete slab, approx. 1470 square feet
  • Living room features a builder-grade TrueHeat TH-36 Zero-Clearance fireplace that I believe must be original to the house.
    • I have attached the PDF installation manual for this unit to this message
    • The fireplace has a natural gas attachment (you can see the key behind the guitar in the interior picture)
    • It appears that there is a vent on the side of the chase, perhaps for external venting per the install manual?
    • Per the install manual: "Never use fireplace inserts or retrofit your Trueheat* fireplace with a wood stove and/or stove pipe." so this avenue is closed to me.
  • The fireplace is flush to the wall, and sits in an external masonry-faced bump-out/chase (see pictures) on the slab.
    • This chase has the following external dimensions:
    • 66.5” Wide
    • 24.5” Deep
    • 11” and 10.5” from the outside of chase to the left and right-hand windows, respectively
    • The ceiling height throughout the house is 105"
  • Given the above figures, my suspicion is (without having opened the walls) that with the ~3” depth of the brick, another ~3.5” for the framing 2x4, plus .5” on each side for interior cement board, the interior size of the alcove would be (max, with slightly greater distance-to-combustibles) :
    • ~52” wide
    • ~22” deep
  • As you can see, the exterior chase itself is quite tall. I’m not sure how this impacts the install or what additional work would be necessary to accommodate this.
  • Since the external bump-out/chase is masonry, I do not have reasonable access to the back of it (I have read this is necessary for newer ZC fireplaces, but I am not sure why)
Photos
View attachment 278187


View attachment 278188
View attachment 278189
Desired Future State/Goals
  • A free-standing wood stove installed in the alcove described above
  • A stove that can heat the front of the house (~15x20 living room, and the 10x20 dining room behind it (they are connected with a pony wall between).
    • My expectations are not that the entire house be heated.
  • The stove is eligible for the new IRS tax rebate
  • I am completely OK with the alcove being full ceiling-height (I do not care about a mantlepiece/hanging pictures etc)
  • A raised hearth would be nice though certainly not necessary
What I have done
  • Visited what seems to be the lone fireplace/stove retailer in my area. I described my issue and showed pictures. They said that without the measurements of the chase, they were unable to recommend a route forward. Understandable!
  • Educated myself on the basics such as clearance, distance to combustibles
  • Put together a library of threads from this forum featuring similar projects, etc. Some are close, but I do seem to have some unique particulars.
Questions
  • What are some suitable next steps for my situation?
  • What aspects of the purchase/install does the IRS tax rebate cover? I assume not the demolition and removal of the old stove/alcove.
  • Is there a short list of recommended stoves that meet the requirements of the alcove size and that satisfy the requirements of the new tax rebate?
  • What, if any, additional complications will the long chimney length introduce to the project? One thread featuring a similar project (albeit with a multi-story house) indicated some difficulties with chimney installation, and the same individual encountered issues with condensationas well.
    • For demolition?
    • For construction?
  • How will the gas line running to the current stove complicate demolition and construction?
  • Would installing a new EPA-compliant ZC fireplace be a superior route in my situation, or would it require external access through the back of the chase (not practicable, obviously!)
  • What additional important questions have I not asked?
Thank you for any help or guidance anyone can offer for this project. As you can imagine, for anything dealing with fire, safety is my first and most important consideration.
Do you have a picture of the top of the chase? If the top is covered by a metal chase cover that would be the easiest way to get internal measurements of that chase. Just pull the top off and you should be able to see what you have. It is possible that is just a masonry structure with no framing inside. I have seen it done both ways here. Not sure how they are typically done in your area.

Other wise you really seem to have done your homework and have a good grasp on what is involved. And you should be able to heat that size house with a single stove fairly easily
 

EbS-P

Minister of Fire
Jan 19, 2019
1,258
SE North Carolina
As a big picture person I’m just going to ask if you considered another location for the stove? Next steps are to make a list of possible stoves. Start finding contractors.

With the higher ceilings the alcove clearance height should be attainable.
Don’t rush you have time. Manufacturers are going to try and get more products certified for with 80% HHV tax credit. Seems like the zero clearance market has the least competition and a good product could really dominate sales, if there isn’t one out yet.
My recommendations for stoves would be, and Vermont castings Aspen C3, or Morso 2b. They are a bit on the small size (ok quite small) but they are on the tax credit list and don’t have a catalytic converter. My preference there. Could go bigger, but I’m out of recommendation there as my personal research for my install it is cheaper to go without the tax credit and go for a Drolet insert. My feelings are that Texas is going to have a tight electric supply for a while (months). Then changes will? (should) be made that will make the likelihood of a similar event less probable than before. Or don’t build a single system for the 1% chance it’s just not cost effective.

Evan
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
25,670
central pa
As a big picture person I’m just going to ask if you considered another location for the stove? Next steps are to make a list of possible stoves. Start finding contractors.

With the higher ceilings the alcove clearance height should be attainable.
Don’t rush you have time. Manufacturers are going to try and get more products certified for with 80% HHV tax credit. Seems like the zero clearance market has the least competition and a good product could really dominate sales, if there isn’t one out yet.
My recommendations for stoves would be, and Vermont castings Aspen C3, or Morso 2b. They are a bit on the small size (ok quite small) but they are on the tax credit list and don’t have a catalytic converter. My preference there. Could go bigger, but I’m out of recommendation there as my personal research for my install it is cheaper to go without the tax credit and go for a Drolet insert. My feelings are that Texas is going to have a tight electric supply for a while (months). Then changes will? (should) be made that will make the likelihood of a similar event less probable than before. Or don’t build a single system for the 1% chance it’s just not cost effective.

Evan
They can't use an insert. I honestly would recommend a cat stove because they will probably get more use in such a mild climate
 

DuaeGuttae

Minister of Fire
Oct 26, 2016
991
Texas
I’m impressed with what you understand already going into your first post. Good job on doing your research.

The gas line should not pose a problem. The lighter should be removed and the line capped.

Often it is easier to install a new ZC fireplace from the back if the facade is hard to work with. Our ZC is stucco outside but huge river rock inside. Your situation is the opposite, so you could choose a ZC if you‘re willing to demo the inside, which you’re obviously willing to do for a free stander. My preference would be the alcove with freestander, though.

Georgetown Fireplace and Patio is (or was a couple of years ago when I talked extensively with them) an authorized Blaze King Dealer. Blaze King makes cat stoves that can burn low and slow and meet the requirements for the tax credit. They also have some close clearances for alcoves, and it is spelled out clearly what dimensions are needed in manuals you can get online. You should be able to have a raised hearth if your alcove is full ceiling height, and it sure is nice to have the stove up a little higher when loading it.

The space you‘re talking about heating could easily be overheated by a woodstove. Even if it isn’t your goal to heat the whole house, how open is that area to the other parts of the house? Could the heat travel there so as not to overheat the front of the house?

I can’t see the details of your pictures well (my screen, not your photos). What flooring do you have in the area where the stove will be? We have ceramic tile over concrete slab. It has the advantage of being non-combustible and easy to clean, but it does absorb a lot of the heat. If you’re on an uninsulated slab without insulated flooring, that will mitigate some of the overheating concerns (but not all of them.)

With a long chimney height, a key damper in the stovepipe is an easy way to deal with an overdraft. With our mild temperatures, though, that’s not as likely as someplace with much more winter, and I’m not certain that your chase is tall enough to put you in danger of that. Do you know how many feet high it is?

Do you have wood already cut (split if necessary) and stacked? If not, it’s a good time to start. Texas summers are so hot in my experience that it could be ready by winter. If you have to buy wood, go ahead and get it now when demand is low, and get it stacked and seasoning.

We use our stove all winter, not all day every day, but I would say quite regularly for about four months of the year. We’re nearer to San Antonio but in Hill Country. It heats the part of the house where we spend most of our time during the day, and we love it. We were especially glad to have it during the winter storm, though we were blessed not to lose power for long because of being close to a fire station. We kept the stove cranking hard the whole week so that we didn’t need to use gas heat for that part of the house, and the kids even slept by the stove so that we wouldn’t have to heat their bedrooms. (Heat from the stove doesn’t reach my husband’s office. It was in the 40’s, so he worked for the week in our bedroom which gets heat that flows up the stairs.)

Good luck on your research. You’ve definitely come to the right place to ask questions and get expert advice from people like Begreen and bholler.
 
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begreen

Mooderator
Staff member
Nov 18, 2005
89,791
South Puget Sound, WA
If demolition is imminent then cutting an inspection hole above the mantel will reveal the inner dimensions of the chase.
 

ATX_stove_wanter

New Member
Apr 26, 2021
2
Austin, TX
I'm blown away by all the replies I have received over just the past day since I posted this!

In an effort to give back, I went through the current EPA list of wood stoves and sorted them by efficiency, then filtering on non-catalytic stoves. I did this because the limited research I did on the topic indicate that catalytic and hybrid stoves are more maintenance-heavy than non-catalytic stoves (although I see that I have gotten a recommendation above to consider a catalytic model!)

To my surprise, there were only several non-catalytic stoves that would meet or exceed the 75% efficiency requirement.

I created a spreadsheet to list these stoves, their dimensions, whether they are alcove-approved or not, and if so, the distance-to-combustibles requirements. When correct alcove measurements are input into the spreadsheet, I will soon add a calculation that will tell if a given alcove can admit a given stove.

Additionally, I have included a link to the manufacturer's page, and MSRP if I could find it (or a guess based off of other sources).

Spreadsheet here

It's very rough and I did it over my lunch break, so I have not added the calculations or improved the layout yet. Perhaps it will be of use to others!

Current Line of research based off of current feedback:
  • Size of stove that will not overwhelm my space
  • Catalytic vs. non, inspired by above comment
Thank you so much for the replies so far; I will read them and reply in more depth after work!
 
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EbS-P

Minister of Fire
Jan 19, 2019
1,258
SE North Carolina
I'm blown away by all the replies I have received over just the past day since I posted this!

In an effort to give back, I went through the current EPA list of wood stoves and sorted them by efficiency, then filtering on non-catalytic stoves. I did this because the limited research I did on the topic indicate that catalytic and hybrid stoves are more maintenance-heavy than non-catalytic stoves (although I see that I have gotten a recommendation above to consider a catalytic model!)

To my surprise, there were only several non-catalytic stoves that would meet or exceed the 75% efficiency requirement.

I created a spreadsheet to list these stoves, their dimensions, whether they are alcove-approved or not, and if so, the distance-to-combustibles requirements. When correct alcove measurements are input into the spreadsheet, I will soon add a calculation that will tell if a given alcove can admit a given stove.

Additionally, I have included a link to the manufacturer's page, and MSRP if I could find it (or a guess based off of other sources).

Spreadsheet here

It's very rough and I did it over my lunch break, so I have not added the calculations or improved the layout yet. Perhaps it will be of use to others!

Current Line of research based off of current feedback:
  • Size of stove that will not overwhelm my space
  • Catalytic vs. non, inspired by above comment
Thank you so much for the replies so far; I will read them and reply in more depth after work!
I like the spreadsheet!
 

gthomas785

Minister of Fire
Feb 8, 2020
505
Central MA
I'm blown away by all the replies I have received over just the past day since I posted this!

In an effort to give back, I went through the current EPA list of wood stoves and sorted them by efficiency, then filtering on non-catalytic stoves. I did this because the limited research I did on the topic indicate that catalytic and hybrid stoves are more maintenance-heavy than non-catalytic stoves (although I see that I have gotten a recommendation above to consider a catalytic model!)

To my surprise, there were only several non-catalytic stoves that would meet or exceed the 75% efficiency requirement.

I created a spreadsheet to list these stoves, their dimensions, whether they are alcove-approved or not, and if so, the distance-to-combustibles requirements. When correct alcove measurements are input into the spreadsheet, I will soon add a calculation that will tell if a given alcove can admit a given stove.

Additionally, I have included a link to the manufacturer's page, and MSRP if I could find it (or a guess based off of other sources).

Spreadsheet here

It's very rough and I did it over my lunch break, so I have not added the calculations or improved the layout yet. Perhaps it will be of use to others!

Current Line of research based off of current feedback:
  • Size of stove that will not overwhelm my space
  • Catalytic vs. non, inspired by above comment
Thank you so much for the replies so far; I will read them and reply in more depth after work!
Welcome to the forum. That's a great spreadsheet. Wish I had something like that when I was picking out my stove.
Just one comment. You puzzled over how the pipe clearance can be less than the stove rear clearance for the Arada - this can happen if you don't assume that the pipe goes straight up. Some people might need to offset back on a 45 or something in order to reach a chimney opening that is closer to the wall, and then the pipe would be closer to the wall than the stove is.

I don't have any other comments on your install other than that it really seems like you're doing your homework. At some point you will have to just rip out the existing fireplace and see what's back there. As long as you have at least a 12" space between combustibles all the way up you can fit a 6" insulated Class A chimney.

It's been mentioned before, but it cannot be overstated. Get started on your wood supply now! The #1 struggle of new wood-burners is improperly seasoned wood. It will take years to build up a proper supply, so you'll thank yourself for getting a head start.
 
Last edited:

begreen

Mooderator
Staff member
Nov 18, 2005
89,791
South Puget Sound, WA
Just because a stove has no alcove specific specs, doesn't mean it can't be installed in an alcove. Testing is expensive and some companies don't test for alcove clearances. The stove may still be installed in the alcove if it meets or exceeds all of the stove clearance requirements.
 

clancey

Minister of Fire
Feb 26, 2021
1,423
Colorado
If it were me I would get a full inspection of that fireplace first and then you will know what you are working with for you see to have a very good grasp of the subject. Austin Texas is more modern and up to date then people might realize and I am sure there are very professional chimney fireplace inspection people around with camera's and stuff. That would be my first step...Since you seem like a up and coming very bright person willing to do the leg work and research check out those stoves for ambiance that will heat very large rooms just for the fun of it..
I have no experience with wood burning stoves and will get mine connected this Wed and someday I hope to light my very first fire. I only have the stove because of wanting to have a back up system in case of a emergency all because of what happened in Texas this past year. Have fun with your research and installation and what a project it is and your just beginning...Mrs Clancey
I
 

clancey

Minister of Fire
Feb 26, 2021
1,423
Colorado
Last edited:

kennyp2339

Minister of Fire
Feb 16, 2014
5,975
07462
Lets not get crazy with stove sizes here, this is Austin Texas @ 1400 sqft, anything greater then 2.5 cu ft will bake someone out, whats the total height of the existing chimney? some stove brands are "tighter" then others and when the company recommends minimum 15ft in chimney height they mean it, other stove brands can get squeaked down a bit with chimney height because there easy breathers, but then again your in a warmer climate and while I dont burn when its 50 out, you might be burning at the same temp.
I think the most serious thing right now is figuring out the class a pipe, certain brands are more narrow then other brands but all still require a clearance from combustibles and with your chase it might be a limiting factor (there might also be supply / demand issues to)