Evening everyone. I started in on the cleaning and inspection today, now that the days are getting shorter and all... I'm running about 15' of smooth wall flex liner, down a terra cotta flue, through an old heatilator and into a PE Super insert. When I went up to inspect the cap and liner connection before sweeping, I found the liner to be about 6" below where I had left it last year! I mean, the liner was no longer attached to the hose clamp on the top plate, but was in the terra cotta flue, as if it had shrunk. It had previously had about 2" of clearance above the hose clamp on the top plate when I tightened it up last Fall. Has this ever happened to anyone else? Something similar happened a couple of years ago and I tugged the liner back up to the top plate and tightened it on. I have sinced replaced that liner with the double/smooth wall flex liner referenced above. I know these liners are supposed to expand and contract but this seems extreme! I am thinking of just attaching one of these and adding the difference in leftover liner I still have. Any thoughts? Thanks in advance.
What size terra cotta flue do you have? All I can think of is if the flue is a bit larger than the liner, it may be dropping down with all the space inside the flue. Doesn't explain why the liner is slipping out of the cap.
You need to have the liner secured with screws at both ends. A stainless steel strap clamp is woefully insufficient. The corrugated liner will compress to some degree under it's own weight and slump to a lower height. Over a long run, even a little compression will result in a short fall
Stainless Liners will not compress or expand, especially the 2 ply smooth-wall liner. If you have 15' you cannot stretch it or compress it. Normally the Top Plate Band Clamp is all you need to hold the liner place, but you could run a couple of stainless screws, to help hold it. 15' can't be that heavy, and if it is attached to your insert, I'm not sure how it could move?????
Mine is about 16 feet... and I am always mindful of it slumping when I remove the cap. I have a section of it in my backyard leftover from the install. It doesn't compress much, but inside of a larger clay flue it can certainly slump. I noticed that installing it.
I installed my own and IIRC I certainly didn’t pull up (increase tension) on the liner prior to securing it at the top. So I essentially let it slump prior to clamping it at the top. Is it possible that the liner was pulled prior to being secured? Is it a straight shot or are there any bends? I agree with a couple stainless screws at the top once pulled back up. Mine is 25’.
Thanks for the responses. It seems that the terracotta flue being somewhat wider than the liner was probably the culprit and it slumped down. Rather than wrenching on it to get it back up to height, I just used some leftover pipe I had left from install and purchased this adapter to connect the two sections. Seems to work.
