A few years ago I installed a stainless liner in my chimney for my wood burning insert. I rarely use it because it doesnt allways work great. It's actually very frustrating. Sometimes the stove will run great and draft very well. Other times it doesnt draft at all. Somtimes the stove will be running for a few hours and be very hot. I will then open it to put in some more wood and it will blow smoke in my face. At that point I stop using it for the day. My chimney is at the east end of my house and the wind is normally coming out of the south west. My liner is insulated. So I've come to the assumption I need to extend my flue taller. I have picked up 6 feet of double wall pipe and a cap. My plan is to get a coupler to connect the flexible liner to the double wall pipe at the top of the chimney. I cant seem to find one. Has anyone seen one of these or is this somthing I will have to custom build?
Help extending chimney flue.
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Basically I'm looking for somthing like this that will connect to the flexible liner that is in the chimney.
Or will a flexible liner attach to this as is?
![[Hearth.com] Help extending chimney flue.](https://www.hearth.com/talk/data/attachments/315/315974-e80184b75ed12d1b6bca0b73a09268cb.jpg?hash=ho0zqRtP0V "[Hearth.com] Help extending chimney flue.")
Or will a flexible liner attach to this as is?
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You need class a chimney to extend your chimney. They sell things to go from liner to class a, but you need to buy the brand of the liner. Here's an example https://www.rockfordchimneysupply.com/products/rock-vent-transition-plate
Im pretty sure the supervent pipe I picked up is class a. The pic I posted above is the only thing I can find made by supervent that I think makes sense. No sites including supervent that sell it show a pic of the bottom or describe it as being useful with a flexible liner.
How tall is your chimney? Which insert are you running? When was the last time your chimney was cleaned? What is the moisture content of your wood?
My chimney is prolly 14 to 16 feet tall. The stove is a Russo. The liner has never been cleaned as it hasnt been used more then 20 times. Looking with my inspection camera it looks allmost like new and obstruction free. I couldn't tell you what the moisture content of the wood I was burning 2 years ago was. I'm betting it was very dry.
I would rule out the moisture content of the wood being you issue first. Get a mositure meter , which are cheap on amazon around $20. Confirm you wood is less than 20.
I cant imagine that was ever the issue. That also doesnt explain a fire burning hot for hours and then when I open the door to add more wood it would backdraft real bad. This happens with the stove at 350 to 400 degrees with a nice bed of hot coal at the bottom. My issue is definitely not the wood I was burning. Also this is not my first wood burning stove or insert.
Ok, well, that is a marginal height on a newer stove. It could very well be the chimney.
We’re just trying to rule other causes out before you start modifying things. It sounds like the setup worked before you added the liner or with old stoves?
Since it was a couple years ago you probably don’t remember if you opened the primary up before, and then opened the door slowly to allow the draft to pick back up. Did you notice whether the weather changed the system performance? If it’s colder, even a marginal chimney can draft fine.
We’re just trying to rule other causes out before you start modifying things. It sounds like the setup worked before you added the liner or with old stoves?
Since it was a couple years ago you probably don’t remember if you opened the primary up before, and then opened the door slowly to allow the draft to pick back up. Did you notice whether the weather changed the system performance? If it’s colder, even a marginal chimney can draft fine.
not sure if it's a timberwolf insert, but that manual says the minimum chimney height is 15 ft. so there's a very high chance that chimney height was an issue especially depending on the outside temperature. Easiest things to check/fix:
- let the fire box stabilize. 5 minutes before you want to reload by-pass the cat and fully open the air intake, crack the door, wait 10 second, crack 1-2 inches, wait 10 seconds, slowly open all of the way
- negative pressure in the house (basement install, exhaust fans (dryer, oven range hood, etc) running or had been running, leaky attic/upstairs windows). so crack a window near the stove 2 inches 5 minutes before you want to reload
- temperature outside when burning and chimney height may have meant you didn't have enough draft
The stove did run good without a liner. Wich I didnt realize it was just sitting in there till I took the front top part off and realized it was just dumping into an open chimney. Wich I felt was very dangerous, so i installed the liner. This was back when I purchased the house. Also yes I would open the primary to let it get flowing good before opening the door and it didnt make a difference. the strange thing is I would even open a window that is about 5 feet from the stove before opening and that didnt seem to help either (very strange). I really think it has somthing to do with the west wind and speed of the wind. I think it's coming over the peak of my second story and cramming air down the chimney. Il post a pic from my backyard. The left side of the picture is west. I read up that the flue has to be 2 feet above a second story that is within 10 feet of it. That is not that case as it is about 20 feet away. I'm just at my witts end and want to use my wood burner. I'm thinking if I add 6 feet to my chimney my issues will be over. But at this point nothing surprises me ahhah. I appreciate all the help and advice as I love this stove on the days it runs good. It's kind of hard to see but all the way to the right you can see my chimney. Excuse the mess I'm getting ready for winter.
![[Hearth.com] Help extending chimney flue.](https://www.hearth.com/talk/data/attachments/315/315999-3cc736ee4022300f21e8ca7d5844dca4.jpg?hash=kBz5sHuurl "[Hearth.com] Help extending chimney flue.")
When I bought thos house there wasnt an exhaust fan in the upstairs bathroom. I did install one and when the wind blows you can hear the tin backdraft plate in the fan bouncing around. So I'm sure that is causing some negative pressure. But still it is very hard to believe that a hot stove is having trouble drafting even with that. I've had a few differnt houses with stoves and inserts and have never had any frustration like this before. But hey I'm all ears. The stove is made by Russo and I'm not sure if russo has any affiliation with timberwolf or not. This stove does not have a cat.
How are you going to support that extra 6' of flue?? Just attaching it to a plate like you referenced will not support it, you need something else.
The outlet on the stove is 6" as is the liner. The sove does exhaust out of the back vs the top. Dont know if that plays a big role.
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How close is that tree to the chimney? Large trees can have similar affects to chimneys being too short in reference to the roof they're near (10-3-2 rule). Large branches near or above can create down drafts into the chimney.
It's about 30 feet to the south. It's not as close as it looks. None of the tree is over the flue but It is a good size tree. I never thought of that tree being an issue but that one went way over my head. The fact that sometimes the stove will run great for days and somtimes it wont allways puzzled me. But it allways ran great before the liner. I feel if the tree was the issue wouldn't it be even more exaggerated without the liner or no?
oh that's much further away than it looks. probably not the tree.
If you're not confident that your chimney is at the minimum required height for your particular stove then I would start there. Adding 6 ft with a straight chimney should have a large impact on draft. If it works some days and others it doesn't then chances are you don't need to add 6 ft to resolve the problems (assuming height is the only problem). An additional 3ft will make a noticeable difference.
Also, timberwolf is somehow associated with Russo. So I don't know what model you have but the 15 ft minimum chimney height requirement I saw is for moel#: EPI22.
It's not cold yet in ny so it's kind if difficult to test this. Come winter I'd rather be ready then messing with this thing. If you feel like 3 feet will be plenty is there any detrimental effects of 6 foot even if I dont necessarily need it?
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