Hello everyone and thanks in advance for your help.
I have an existing chimney that I believe was wood at one point. The reason I think it was wood is that the chimney above the ceiling is 8" triple wall. I have a label and found a match. in an old wood stove installation catalog from 1983. At some point, the stove was converted to gas at which point they dropped 6" double wall class B venting down the entire length of the chimney which is about 35'. I want to convert back to wood as I just found a nice Jotul F CB 3 and I installed a gas furnace for my primary heat source. I had originally assumed that the class b vent only went from the gas stove to the ceiling box and that I would only need to replace that class B section. However, I now know that I need to get rid of the entire length of class b all the way to the rain cap.
This is where my questions comes in;
1) I can't figure out how the class b is supported. I can twist it and it just spins including the rain cap. I had thought that it was locked into the ceiling support box but it doesn't seem to be. I also can't lift it up. Is the rain cap supporting it? I haven't been able to access the top yet because I'm waiting for a friend with ropes and harnesses. The roof is a 45 degree pitch.....
2) Is the ceiling box correct for the 8" triple wall? I can't tell if it's locked into the ceiling box or if it is just resting on the box. If I can figure out how to remove the class B, I need to transition from the 8" triple wall to 6" double wall all the way to the stove (I can't do single because of stove to wall clearance) and I don't know how to do this.
Thanks everyone!
![IMG_4851.jpeg IMG_4851.jpeg](https://www.hearth.com/talk/data/attachments/284/284683-85e6875e098376c74edf31f567366397.jpg)
![IMG_4852.jpeg IMG_4852.jpeg](https://www.hearth.com/talk/data/attachments/284/284682-f99afecdab31be603717ff8c2790448d.jpg)
![IMG_4853.jpeg IMG_4853.jpeg](https://www.hearth.com/talk/data/attachments/284/284681-10010c058fa061c933797ce88eea82bf.jpg)
![IMG_4854.jpeg IMG_4854.jpeg](https://www.hearth.com/talk/data/attachments/284/284680-c0e2673d78533fe51c3ef42a97bc001b.jpg)
![IMG_4856.jpeg IMG_4856.jpeg](https://www.hearth.com/talk/data/attachments/284/284679-d098692ee19418ca0ec73a6bd1599104.jpg)
![Chimney conversion from gas to wood Chimney conversion from gas to wood](https://www.hearth.com/talk/data/attachments/284/284687-0bba7d5992fd3a4a4c5e56bb4f3aec30.jpg)
I have an existing chimney that I believe was wood at one point. The reason I think it was wood is that the chimney above the ceiling is 8" triple wall. I have a label and found a match. in an old wood stove installation catalog from 1983. At some point, the stove was converted to gas at which point they dropped 6" double wall class B venting down the entire length of the chimney which is about 35'. I want to convert back to wood as I just found a nice Jotul F CB 3 and I installed a gas furnace for my primary heat source. I had originally assumed that the class b vent only went from the gas stove to the ceiling box and that I would only need to replace that class B section. However, I now know that I need to get rid of the entire length of class b all the way to the rain cap.
This is where my questions comes in;
1) I can't figure out how the class b is supported. I can twist it and it just spins including the rain cap. I had thought that it was locked into the ceiling support box but it doesn't seem to be. I also can't lift it up. Is the rain cap supporting it? I haven't been able to access the top yet because I'm waiting for a friend with ropes and harnesses. The roof is a 45 degree pitch.....
2) Is the ceiling box correct for the 8" triple wall? I can't tell if it's locked into the ceiling box or if it is just resting on the box. If I can figure out how to remove the class B, I need to transition from the 8" triple wall to 6" double wall all the way to the stove (I can't do single because of stove to wall clearance) and I don't know how to do this.
Thanks everyone!
![IMG_4851.jpeg IMG_4851.jpeg](https://www.hearth.com/talk/data/attachments/284/284683-85e6875e098376c74edf31f567366397.jpg)
![IMG_4852.jpeg IMG_4852.jpeg](https://www.hearth.com/talk/data/attachments/284/284682-f99afecdab31be603717ff8c2790448d.jpg)
![IMG_4853.jpeg IMG_4853.jpeg](https://www.hearth.com/talk/data/attachments/284/284681-10010c058fa061c933797ce88eea82bf.jpg)
![IMG_4854.jpeg IMG_4854.jpeg](https://www.hearth.com/talk/data/attachments/284/284680-c0e2673d78533fe51c3ef42a97bc001b.jpg)
![IMG_4856.jpeg IMG_4856.jpeg](https://www.hearth.com/talk/data/attachments/284/284679-d098692ee19418ca0ec73a6bd1599104.jpg)
![IMG_4858.jpeg IMG_4858.jpeg](https://www.hearth.com/talk/data/attachments/284/284678-ff8fdfa0053045119b12164e983481f3.jpg)
![IMG_4860.jpeg IMG_4860.jpeg](https://www.hearth.com/talk/data/attachments/284/284684-d1af3a0f36362fd250c70a67eceaabff.jpg)
![IMG_4859.jpeg IMG_4859.jpeg](https://www.hearth.com/talk/data/attachments/284/284685-ec587b36eb494d5d24925747e6093fde.jpg)
![Chimney conversion from gas to wood Chimney conversion from gas to wood](https://www.hearth.com/talk/data/attachments/284/284687-0bba7d5992fd3a4a4c5e56bb4f3aec30.jpg)
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