Flue hygiene & airflow (newbie)

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Kominar

New Member
Dec 8, 2020
19
New Brunswick
Still learning, as we've only had our PE Super LE since last March - so less than a full season of burning. I'm wondering if we're (over)due for a chimney sweep or if there's another issue that needs to be addressed in the insert itself. Apologies for the extra detail below, perhaps another newbie like me will find it useful:

Lately I've been noticing that starting the fire is getting harder, esp. if the firebox & flue are still warm (but not hot). Even with the door open an inch, there's more smoke the first minute or two than I recall before, and occasionally I need a 2nd or even 3rd attempt, with some extra birch bark or paper. Once it gets going, it all seems normal and easy after that.
I climbed on the roof and took a look down the chimney. Some build-up (<1/8"?) of very soft soot, fairly consistent along the length of the flue, dark grey or almost black - but nothing creosote-like.

We don't burn 24/7 - we find it gets too hot on most winter days - but we only do colder starts maybe 1-2 a week (if that), after emptying the slightly-glowing ashes, so even then the flue is not truly cold. The rest of the time I restart the fire on a hot bed of coals in the mornings, and maybe again in late afternoon - and in those cases it is easy with a few thicker pieces of kindling, and the fire burns well after that. But it makes me wonder whether 1) these daily re-starts contribute to more soot and poor airflow, or 2) if it's my tendency to burn at a lower intensity (smaller loads, with secondary flames but not very vigorous), or 3) both.

We have an external chimney, and burn a mix of well seasoned and some decently seasoned hardwood (maple, birch, beech, ash) - I'd say about 2/3 of that not optimally dry yet, though I don't know moisture content. We've gone through about 3-4 cords of wood since the insert was installed... perhaps going a full season is too long between sweeps?
 

kennyp2339

Minister of Fire
Feb 16, 2014
6,545
07462
Check your cap, make sure it isnt plugged or gummed up, pull your baffle and make sure chimney crust hasnt fallen and creating a restriction, other then that, buy a moisture meter and test your supply. I know for myself I need 2-3 years for my splits to dry out to 15-18% moisture content.
 

stoveliker

Minister of Fire
Nov 17, 2019
4,525
Long Island NY
You say "more smoke". Is that more smoke *in the room* or in the firebox and out the chimney?

The former could be a restriction, the latter too wet wood. (Of course wet wood leads quicker to restrictions, so both may be the case here.)

Yes, I'd sweep more often until you know what to expect. Get a soot eater, so you can do it yourself. (And if your insurance wants to see a sweeping bill, have the end of season cleaning done by a pro.)
 

Kominar

New Member
Dec 8, 2020
19
New Brunswick
Thanks for the quick responses!

Chimney cap totally fine. Haven't checked the baffle... I guess I'll wait for a warm day later this week so everything can cool; will have to look up how to do this with our insert.
By "more smoke" I mean just in the firebox, nothing alarming, just enough to douse the starting flames. Cool idea with the dual sweeping approach, thanks.

I do suspect my wood isn't nearly as dry as desirable, and even in the shed there's a bit of dripping from the leaky roof here and there. I always have some drying in the house too, but only enough for a couple days supply on cold days.
 

NewGuy132

Member
Jan 22, 2021
98
Central MA
I got a mid season sweep and I am glad that I did. Its my first year burning and I was using some marginal-bad wood. Turns out I had a small chimney fire at some point and I was about 30% clogged up.
 

Kominar

New Member
Dec 8, 2020
19
New Brunswick
A quick update (and another question/problem):

So I got the SootEater, waited for a warm day, let the insert go completely cold, and did the cleaning from the bottom up. Went fairly well (but see below :rolleyes:), following some useful forum advice on how to remove a PE Super LE baffle.
The one minor glitch I encountered while feeding the rods up the flue is that 3 sharp screws stick out a good half inch into the flex liner connector, and they ended up really scratching the rods. Is this normal?? Next time I may have to look into cutting them off, unless there's a better solution? Or just sweep from top down, which may be easier anyway.
The sweep yielded about 2-3 cups of soft dark soot, so nothing too dramatic...(?)

However, I forgot to stuff a rag into the secondary air supply tube before the sweeping. !!! (in my defense, I was also dealing with a flooded garage thanks to all the rain & thaw).
I assume some of the soot got in - because after replacing the baffle and starting the fire, I am noticing no secondary flames at all (and it also seemed like it took a long time to a vigorous flame). Of course, everything is too hot now so my plan is to revisit this tomorrow. What do I need to do to try to clear this tube? The firebox seems too tight to fit any common vacuum accessory over the tube, and I definitely don't want to be taking the whole insert apart!
Thanks!!
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,756
South Puget Sound, WA
Oh oh, can you point me to the forum posting on removal of the baffle? It definitely should have a warning about stuffing a rag in the secondary tube. If not, I will add this.

Now there is a lot of soot down in the EBT. The most thorough method would be to remove the EBT and clean it out. In lieu of that you might be able to ductape a 2' length garden hose to the end of a shopvac hose to suck out as much as possible from the secondary tube.
 

Kominar

New Member
Dec 8, 2020
19
New Brunswick
Oh oh, can you point me to the forum posting on removal of the baffle? It definitely should have a warning about stuffing a rag in the secondary tube. If not, I will add this.

Now there is a lot of soot down in the EBT. The most thorough method would be to remove the EBT and clean it out. In lieu of that you might be able to ductape a 2' length garden hose to the end of a shopvac hose to suck out as much as possible from the secondary tube.
Yup, the posting definitely included a warning - in fact by you, begree. I was just too damn distracted by the flooded garage, and didn't go back to the forum posting once I resumed the sweeping prep.
I'll try the garden hose method first, since it sure sounds like the other option will be a lot more complicated! <><><>
Unlikely to be something else, right? (like the baffle not replaced correctly?)

(note: after an hour or so, I did see a few secondary flames, here and there - and began thinking perhaps the soot would reignite and eventually pass through.. doesn't seem to be the case)
 

Kominar

New Member
Dec 8, 2020
19
New Brunswick
Oh oh, can you point me to the forum posting on removal of the baffle? It definitely should have a warning about stuffing a rag in the secondary tube. If not, I will add this.

Now there is a lot of soot down in the EBT. The most thorough method would be to remove the EBT and clean it out. In lieu of that you might be able to ductape a 2' length garden hose to the end of a shopvac hose to suck out as much as possible from the secondary tube.
Begreen: I did not notice any gasket between the tube and baffle; can't tell if it was missing, or if it may have disintegrated(?). Seems it'd be hard for it to stay in place when returning the heavy baffle to its position, no?
The side insulation also isn't very tight against the side rails at all - is that something that routinely needs replacement? (we've only had the insert for a year).
Still waiting for things to cool down so I haven't tried vacumming the air supply tube yet, but presumably all of the above issues could also be contributing to not seeing those secondary flames?
Apologies for all the rookie questions...
 

Kominar

New Member
Dec 8, 2020
19
New Brunswick
Update:
So I removed the baffle again today... and yes, did find remnants of that gasket (a few disintegrating pieces - so I may need to revisit). Per Begreen's advice, I attempted to clean out the secondary air supply tube with a piece of a garden hose ductaped to a vacuum hose. I
was actually able to get almost all the way to the bottom of the vertical section, by flattening the hose to fit the tube's narrow rectangular profile. Hard to tell what I managed to suck out of there... but the result: the secondary flames are back!!** :cool:

(To be honest, I wasn't too hopeful at first - the fire started quite different than it used to before the sweep - the firebox seemed much darker, with no signs of life from the baffle - and it took an hour before those secondary flames appeared. Even now they seem to be more on one side of the baffle for some reason... otherwise the fire looks great and feels hotter than before the sweep.)

**But I also see something I had not observed before: from the back corner of the baffle, occasionally a thin laminar flame runs along the underside of the baffle towards the front. Could that be the incomplete gasket issue, creating a bit more of an air leak? _g
 

bigealta

Minister of Fire
May 22, 2010
774
Utah, NJ
Update:
So I removed the baffle again today... and yes, did find remnants of that gasket (a few disintegrating pieces - so I may need to revisit). Per Begreen's advice, I attempted to clean out the secondary air supply tube with a piece of a garden hose ductaped to a vacuum hose. I
was actually able to get almost all the way to the bottom of the vertical section, by flattening the hose to fit the tube's narrow rectangular profile. Hard to tell what I managed to suck out of there... but the result: the secondary flames are back!!** :cool:

(To be honest, I wasn't too hopeful at first - the fire started quite different than it used to before the sweep - the firebox seemed much darker, with no signs of life from the baffle - and it took an hour before those secondary flames appeared. Even now they seem to be more on one side of the baffle for some reason... otherwise the fire looks great and feels hotter than before the sweep.)

**But I also see something I had not observed before: from the back corner of the baffle, occasionally a thin laminar flame runs along the underside of the baffle towards the front. Could that be the incomplete gasket issue, creating a bit more of an air leak? _g
can you post a short video or at least some pics?

And starting Top Down fires creates way less smoke and gets the secondaries firing very quickly. Here's a video of how to do it if you don't yet know.

 

Kominar

New Member
Dec 8, 2020
19
New Brunswick
can you post a short video or at least some pics?

And starting Top Down fires creates way less smoke and gets the secondaries firing very quickly. Here's a video of how to do it if you don't yet know.


Thanks, bigealta. I didn't take any pics while I was doing it, but can do so when I replace the gasket in the near future.
Or did you mean that laminar back-flame?

I hadn't seen that video before (thanks!), but typically I do start my fires top down, though perhaps not as multi-level as in this video.
 

bigealta

Minister of Fire
May 22, 2010
774
Utah, NJ
Thanks, bigealta. I didn't take any pics while I was doing it, but can do so when I replace the gasket in the near future.
Or did you mean that laminar back-flame?

I hadn't seen that video before (thanks!), but typically I do start my fires top down, though perhaps not as multi-level as in this video.
Both if u can. You would be amazed at what guys here can see in good quality pics.

If you are doing the top down right u should be getting good secondary flames in 5-6 minutes. Possibly even earlier.
 
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Both if u can. You would be amazed at what guys here can see in good quality pics.

If you are doing the top down right u should be getting good secondary flames in 5-6 minutes. Possibly even earlier.
Good quick secondaries from a good top down fire are awesome, very rewarding to see. However, with marginal or subpar firewood, one must come to appreciate the art of delayed gratification... 🙄 You'll get there eventually, after building up a supply of 2 - 3 year dried, split & stacked FW, and then it's like, ahhhh, this is so awesome! 😊
 
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