Downdraft after lining

[eujamfh]

I am hoping you guys can help explain why my wife is getting a downdraft after we lined the chimney. We have a Buck 91, and my wife has been running it on weekend. (Too hard to keep twp going with me being deployed during the work week.) Anyways, last year we had it as a slam in and it drafted with no problem. This year, she has had two occasions where she had a downdraft which pushed smoke into the room. First time she reports it was bad since she just put a bunch of wood, some paper and a firestarter in there and like last year assumed it would be fine. She was wrong and had some smoke back up. Anyways today she started it, and was more careful to get small fire going...she is an educated user, but said she still had a bit of a problem reversing the draft.

We put in a 8" fully lined SS liner that runs from the stove to the top of the 30ft external chimney. When I was home on leave a month ago, I ran it and was actually concerned that the new liner was causing too much draft. I had to completely close the air and only opened them when things were really settled and even a tiny bit at that. Stove has a new gasket and is not leaking as best I can tell and since i was able to get proper temps an a lazy roll...I just chalked it up to the new liner and a strong draft.

but now with her report of a downdraft until she gets it going....I am confused. She did claim that once the draft started, it was strong and worked as it did when I was home.

Thoughts?

Matt

 

[Shari]

Well..... is the chimney cap partially clogged? Has anyone checked the chimney since install? Is the wood well seasoned?

 

[EatenByLimestone]

Was it windy? It only takes one odd gust...

Matt

 

[branchburner]

Just sounds like a cold flue, unless it's a negative pressure problem with a basement install. Maybe if she first builds a really small paper and kindling fire to warm the flue, letting it burn out, then a normal fire after that?

 

[JotulOwner]

I can't explain why, but, on occasion, I get a strong down draft when the stove is cold (I don't burn 24/7). I can tell right away when I open the stove door (cold air blowing at me) and I know it will be a challenge to reverse it without getting smoke in the house. I open a window on the side the wind is coming from before trying to light a fire. I find that downdrafts also occur when there is no strong wind or breeze. Downdrafts also occurred more often in past years when I had a Metalbestos cap on the chimney. Since I bought a larger screened cap, it has only happened once (recently).

 

[eujamfh]

Wood is definitely dry. Liner is clean, brand new cap with only two fires since it was done and it drafted fine when I was home a month ago so no obstructions. Was not particularly windy from what she stated. She did a small fire the last time and had much less of a problem. Since I am not there hard to really tell. Hoping its just a cold flue and she did not use a small enough one to get things going. She did say once it was reversed, no problems at all...just thought it interesting since never had an issue when it was a slam install.

 

[Renovation]

These things can be mysterious, because there are so many possible causes/things that might have changed.

It's disappointing that an insulated/lined chimney that tall would backdraft. But it is masonry, and could be cold. Could there be anything in the house blowing out air--bathroom/stove vent, etc? Has she tried cracking a window nearby while she starts it?

HTH, and good luck!

 

[WES999]

You might try preheating the flue, I use a propane torch the warm up the flue in my basement stove (outside chimney), a heat gun would probably work well too. Works well for me.

 

[Northeaster1]

I 2nd the advice to just start with a paper fire, to warm up the flue. A dozen or so separately balled up newspaper pages. When that goes out, or is near out it should be updrafting, and she can put in some more paper and kindling.

 

[VCBurner]

Try reverse starting the fire with the bigger splits on the bottom up to kindling on top of a firestarter, then a few balls of newspaper to top it off. Is the stove in a fireplace or throught the wall? You never had a downdraft before installing the liner. How long did you have the stove running without the liner? Is there a different cap on it also?

 

[CHIMENEA]

I have the same problem with my insulated liner since I dont burn 24/7, sometimes the downdraft is pretty steady. Through the process of it happening and airing out the smoke with a box fan at a nearby sliding door I've found opening the patio door gives the startup fire/supercedar the air it needs to get up the chimney.

If I were to try and heat the flue up with newspaper burns with the sliding door closed the downdraft will snuff the flames and smoke the room even with the insert door open. I doubt a propane touch would fair much better when I get a good down draft.

I was just glad that I found a solution that worked. Other than that initial draft the insert performs great at all other times.