Heatilator fireplace double-wall chimney new install problem

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Cedar 25

New Member
May 31, 2023
4
Upper Midwest
After a number of years of following this forum I finally made the plunge and purchased a wood burning fireplace to replace our gas one.

I am completing installation of a new Heatilator accelerator fireplace, and have found a serious problem with the inner chimney. At some point during the chimney assembly the inner wall went past the seat of its seal at the top of the fireplace and now the damper will not fully open. Every additional section of chimney seated fine so I think overall every section is secured. But I am in a panic over this. I searched the forums and the internet to see if others have encountered this problem and came up empty. I am wondering if anyone has seen this before and familiar with the options to handle it.
 
Are you saying that the inner wall of the chimney pipe slipped? It seems unlikely, but if so, that's a defective pipe and must be replaced. Or does the flue collar have a defect that is causing the bind? Can you get a camera up in the pipe with the damper open to see what is binding? It may just be someone used a too-long screw at the flue collar. If so, take wire cutters and snip it flush.
 
Are you saying that the inner wall of the chimney pipe slipped? It seems unlikely, but if so, that's a defective pipe and must be replaced. Or does the flue collar have a defect that is causing the bind? Can you get a camera up in the pipe with the damper open to see what is binding? It may just be someone used a too-long screw at the flue collar. If so, take wire cutters and snip it flush.
Similar to other Home Hearth Technology products the fireplace recommends their SL300 series double wall air cooled chimney. The chimney sections snap and lock into place with the inside chimney wall slipping inside the segment below it and the external chimney wall slipping outside the segment below it. The chimney collar is integrated as part of the top of the fireplace unit. Sticking my head into the firebox, looking up and trying to open the damper I can see it hitting what appears to be the inner chimney wall of the first chimney piece. The damper isn’t opening far enough for me to slip my hand up and feel but that’s what it looks like. There’s a fair amount of light as the inside chimney is brand new and reflecting much sunlight from above. The words slip and lock make the process sound easy but many of the chimney segments rarely assembled easily so there was some pushing down involved.
 
The person that helped me with this project is retired from the home construction industry and his opinion is that the damper is not aligned properly. He doesn’t think it’s possible for the inside chimney wall of the first section to be slid or forced down past the flue collar.
 
The person that helped me with this project is retired from the home construction industry and his opinion is that the damper is not aligned properly. He doesn’t think it’s possible for the inside chimney wall of the first section to be slid or forced down past the flue collar.
That's what I would expect too and why I suggested inspection.
 
A Tech from the fireplace store found that indeed the inner chimney had fallen past the bead/groove that it’s supposed to snap in to. He was able to push a good part of the inner chimney back up and then screwed into place. I checked out his work afterwards and using a thin feeler gauge most of the inner chimney is in its groove now but there is a part that is not seated and the feeler gauge appears to be entering the cooling air space of double wall. My concern now is smoke and co2 escaping through the joints of the outer chimney wall and filling the chase. I’ll share photos with my salesperson to see if he can get a second opinion in their office.