Sparks & smoke suddenly came out from air intake

[Kominar]

Help! Without any warning, sparks came out from the (air intake?) gap that's between the vertical wall above the door and the flat mantle, and very noticeable smell of smoke filled the living room!
This happened after I had shuffled the logs and closed the door - luckily I was there to make sure nothing worse happened. Once I turned off the fan, the sparks stopped. The insert (Pacific Energy Super LE) burning fine* the whole week (but see below) - What do I need to do??

*of course, need to add some background on the likely culprit:
I cleaned the chimney from the top recently (with SootEater), and even replaced the gasket on the baffle. During a chimney clean a couple of years ago I had made the mistake of not plugging the air intake tube with a rag (https://www.hearth.com/talk/threads/flue-hygiene-airflow-newbie.191795/post-2577085) but luckily vacuumed out the soot from the tube afterwards, per advice by @begreen. This time I didn't forget the rag, but enough of it stuck out of the tube and got caught by the rotating brush and pulled out - which I didn't find out until I was done with the cleaning. So, tube filled with soot again.
Again, I used the same method of vacuuming it out (stiff piece of garden hose ductaped to vaccum). While the initial performance of the insert definitely seemed a bit impaired (reluctant secondary flames, etc.), after a few days things returned to normal - until now!

I'm assuming there's some more stuff caught in the EBT that I could not reach with my vacuum ...and maybe it finally shifted somewhere else to start causing problems? Is my only (or best) solution to pull out the EBT? (is there a good instruction thread on that?) Is there any other explanation, e.g. something to do with the baffle/gasket?
Thanks for all your advice!!

 

[EatenByLimestone]

Since this is an insert, is the liner attached?

 

[Kominar]

Hmmm... I'm assuming so. The insert was installed by the local distributor/service company and I'm pretty sure they took care of the liner. Was your question because that would be another possible issue? (but wouldn't that come up much earlier?)

 

[begreen]

This is a first for my ears. Your theory may be correct or perhaps some creosote fell into the convective jacket. That gap is the top part of an outer metal that forms a duct around the stove body from the blower outlet to that opening.

 

[Kominar]

Thanks for your thoughts, begreen.
I have to digest that second explanation! (and try to visualize that space). Didn't think that was even a possibility, but I don't have a clear sense of how the air moves between the intake tube and other areas. I'm definitely worried to see what happens if I turn on the blower again. The chimney sweep produced only very fluffy deposit - I felt quite confident I could vacuum it out but maybe that's also why it travelled into all kinds of spaces once it entered the intake tube.
Is taking the whole thing apart quite a process?

 

[Kominar]

Well, I was more curious than worried... so I turned on the blower! (at this point the fire isn't burning but there are still lots of glowing coals). No problem this time, nothing came out of that gap, not even the faintest smell of smoke.
But for whatever reason (related or not), the fan on the right side is quite loud now, like it's slightly obstructed by something.

 

[EatenByLimestone]

Hmmm... I'm assuming so. The insert was installed by the local distributor/service company and I'm pretty sure they took care of the liner. Was your question because that would be another possible issue? (but wouldn't that come up much earlier?)

Im assuming that the sparks flew out outside the stove. Maybe I misunderstood.

 

[Kominar]

They did fly out, right at me after I closed the door.
The liner is definitely attached; I remember now watching them do it.

 

[EatenByLimestone]

Top or bottom of the stove?

 

[Kominar]

Top, through the blower gap that's 2-3" above the door

 

[EatenByLimestone]

Ok, that’s what I read it as. On the freestanding super, all air inlets are on the bottom.

So if the sparks came out the top. They either blew their way completely around the stove from the bottom, which is possible with the blower on, or came out the top, where the liner attaches. I’d pull the surround and make sure it’s attached.

 

[Kominar]

Ok, thank you for the explanation, EatenByLimestone - I will do that as soon as the insert cools down today. I can't see how the liner would have become detached but I suppose there's some chance of that with the chimney sweep?

 

[EatenByLimestone]

Its possible that they didn’t secure it correctly on the install or it could have knocked itself lose on a sweeping. That’s why I’d check it to make sure.

 

[Kominar]

UPDATE:
Ok... so i haven't looked into the detached liner hypothesis, or done any more vacuuming of the air intake tube to see if something that had remained there shifted and can be sucked out. Instead, when I got ready to do the above I think I may have discovered the culprit behind the sparks and smoke:

The right blower, which directs the air into the gap from where smoke and sparks flew out (arrow in photo 1), shows obvious signs of some scorching of the fan blades (photo 2).
Most blades are intact (the photo shows the worst one), just slightly discoloured, and a few have tiny sections missing. The fan turns fine, without a wobble. So at this point I'm not too worried about the fan.

Now the question: how did an ember(?) get into the fan in the first place??
I don't recall seeing anything fly out of the fire when I was moving the logs around with the door open... and I can't see an easy route for that ember to make it into the fan blades in the first place. Or...?
Any other explanation? It doesn't seem likely that fine soot from my botched chimney sweep would have made such a burn mark, unless it ignited a clump of ash/dust etc. (and how would it have ignited, from the fan motor?).

I'm still pretty confused about the whole incident... though I'm feeling a bit more confident that this issue was independent of the potential soot remnants in the air intake system (or was it?? - are the blower system and air intake physically directly connected?)

Thoughts? - Thanks!

 

[bholler]

Yup an ember fell out and got sucjed into the stove. I see it 3 or 4 times a year honestly. Turn the blower off on inserts when the door is open guys

 

[Kominar]

Oh wow, interesting! Didn't think that was possible - what's the actual path of it, just through the gaps in the surround?
Must be a rare enough of an event (I must open the door easily 2000 times per burning season) but I can see that your solution would prevent it from happening!

 

[bholler]

Oh wow, interesting! Didn't think that was possible - what's the actual path of it, just through the gaps in the surround?
Must be a rare enough of an event (I must open the door easily 2000 times per burning season) but I can see that your solution would prevent it from happening!

Yeah there is an open path the blower sucks air in and pushes it out the top