Jotul F400/Castine: air wash messed up?

[Sparky31]

I had my Jotul F400/Castine professionally cleaned a few days ago by the same licensed/insured sweep service that installed the stove. But this time the "sweep" was a 20-something who didn't seem familiar with the stove. Last time it was cleaned, it was by the very experienced owner of the company.

Tonight I made a fire for the first time since the recent cleaning. For the first time ever in 6 years of running the stove, the front glass get sooted up heavily. You can barely see the flames inside. This has never happened in literally hundreds of prior burns. Wood is the same 2+ year seasoned red oak I've been running for a long time; no change there.

Per the manual, the F400 has an air-wash feature that runs warm air across the inside surface of the glass. In the past the only soot buildup was in the lower left and lower right corners of the window. I could always see the flames & coals very clearly. Could the young technician have reinstalled the jet assembly (don't know the correct name) in some way that has disturbed the air-wash system? During the cleaning I stayed in the room and closely watched everything he did. He did get that 4"x8" plate (don't know the name of the part) reinstalled on top of the jet assembly, and I didn't see any other loose parts.

But the glass is getting sooted up like crazy, and that never happened before this cleaning.

ETA: the sooting effect is the worse with the front air lever turned down low. During the initial burn with lots of flames, it's not too bad (though worse than ever in the past). But once the jets are going and I turn down the air (over time), the sooting gets a lot worse.

Here is a pic showing the soot in the center of the window. This has never happened before.

 

[bigealta]

Hmm.. I burn my f400 everyday during heating season. Never seen a soot pattern like that on mine.

Your glass is mounted differently than mine. I don't have those type of clips and my longer clips are in different locations.

 

[bigealta]

What's that in the bottom corner of the glass? Hard to see in the pick but it looks like the corner is broken? Or maybe it's just soot? Strange that it's a different color than the soot in the rest of the glass?

 

[bigealta]

How many fires have you had since the cleaning?
If it's just 1 maybe you just pulled some wet pieces. Certainly possible with 2 year oak.

 

[EatenByLimestone]

Was the wood too close to the glass?

 

[Sparky31]

Thanks for the responses, I appreciate it a lot.

>How many fires have you had since the cleaning?
>If it's just 1 maybe you just pulled some wet pieces. Certainly possible with 2 year oak.

Tonight is the first fire since the cleaning. But the wood came from the rack I keep in the living room with the stove, so no exposure to the outside weather. The wood is super dry red oak and the relative humidity in the room is 35%. So no variance in the fuel.

>Was the wood too close to the glass?

I'd say no, I used my standard fire lay. Plus, I put less wood in than normal because just before this week's cleaning I had a puffing/dragon event for the first time. I had cut the air down too low and too fast on very dry wood, which I realized after looking up those symptoms at this Hearth.com FAQ. So my fire tonight was very conservative.

I've just never seen sooting like this before on this stove.

 

[stoveliker]

The back puff and the soot could be consistent with a vein of wetter wood - on the inside.

How do you store the wood outside before you bring it in?

 

[bigealta]

Try another few fires. look for any hissing or smoke coming from the ends of the splits.

 

[Sparky31]

>How do you store the wood outside before you bring it in?

I keep my wood in racks off the ground, in sunlight, and with top covers. The wood that I used for both the back puff event and tonight's fire has been stored in my living room for about 3 weeks, as we have not burned much lately.

>Try another few fires.

Yeah, I noticed as the evening has gone on that the rate of sooting has gone down a fair amount, even with variances in the air setting as I've added wood. I will run through the burn cycles for a few more nights and report back to the forum.

 

[stoveliker]

Top cover with a tarp?
Did you put a pallet on first and then the tarp?

Condensation at the inside of the tarp can leak on a single split (and stream down).

 

[EbS-P]

How is the stove vented? The sweep take the cap off a clean out T? The air wash comes up the side burn plates (I think ). I don’t see how that could get blocked unless he plugged the air intake and forgot to unplug it.

 

[begreen]

It sounds like this stove has been burning right for several years. Is that correct? If so, I'm going to assume you know how to run it and have good dry wood. The F400 usually keeps a nice clean window, so it's definitely not right. There is an air deflector in front, above the door. Is that properly in place?
I think there is a baffle plate that stands upright in the middle of the secondary air chamber. Wondering if that is in the correct position?

 

[bigealta]

It sounds like this stove has been burning right for several years. Is that correct? If so, I'm going to assume you know how to run it and have good dry wood. The F400 usually keeps a nice clean window, so it's definitely not right. There is an air deflector in front, above the door. Is that properly in place?
I think there is a baffle plate that stands upright in the middle of the secondary air chamber. Wondering if that is in the correct position?

There is a deflector plate that 's maybe a 3" x 8" piece of metal that sits horizontal on top of the baffle (between the top of the baffle and the top of the stove). It deflects exhaust gasses around it to slow them down before exiting to the stove pipe.

I've accidently run my f400 a few days with it lying flat (i forgot to stand it back up after cleaning) and it did not seem to make much of a difference. But that's just a few days and with my set up, so could be different for others?

I don't know about an air deflector piece above the door?
I always thought my cast baffle/secondary burners (they are 1 piece in my f400) was the air deflector? But i just looked (thru the glass with a hot fire) and see 1 bolt in the front middle of the baffle that looks like it could be securing a deflector on the front top of the baffle?

Edit: After looking at the schematic and parts breakdown i'm confused as to exactly where the air deflector part is attached to? and also i thought my cast baffle and secondary burn plate was 1 piece but now i'm not so sure?

 

[Sparky31]

Followup:

Tonight I cleaned the glass completely then did a burn. Wood from the same rack, using my standard fire lay, everything the same as last night and the years before.

Result: the stove ran perfectly and the glass stayed clear as it has done all these years. The bottom left and bottom right corners of the glass got dirty, but that's always been the case as the air wash doesn't extend to those bottom corners. I got the stove up to about a 600 degree top temp with lazy yellow low flames, and nice secondary jets with some blue flames. The center 75% of the glass stayed completely clear throughout the cycle, and I couldn't ask for a better burn.

Some pics:

Compare this pic of the inside of the glass late in the burn with the one I posted last night. Crystal clear down the middle.

So I just don't know what happened with the sooty glass last night. It's hard to believe it was just a coincidence after the cleaning, but I doubt I'll ever know.

Thanks to everyone who responded, Hearth.com is an amazing resource.

 

[stoveliker]

If I were you, I'd carefully "feel" the weight of your splits; I think you have had a wet one or two in there. They'll be heavier.

It happens to the best folks.

 

[bigealta]

Yeah a couple wet ones must have gotten in. Ones previously seasoned in the bottom of the rack, overly knotty, rain somehow got on them when seasoning? Any way it happened we may never know as you said but i'd bet money that was your problem.

 

[bigealta]

Those "angel wings" showing up like that in 1 burn is telling you your wood has a higher moisture content than you think.
With really dry oak, and those temps you are burning at, angel wings are quite a bit smaller and a lighter color than those black corners, or they are not there at all. (In my experience)

 

[bigealta]

air deflector follow up.

Yes i confirmed the air deflector is attached to the top of the baffle. I assumed it was part of the baffle casting but found it is a separate piece bolted to the top of the baffle.

 

[EbS-P]

air deflector follow up.

Yes i confirmed the air deflector is attached to the top of the baffle. I assumed it was part of the baffle casting but found it is a separate piece bolted to the top of the baffle.

The baffle is two pieces. Cast iron top and SS bottom with the holes. It can be removed out the door after.
The air deflector #38 looks like it bolts to the front cast iron face frame.

https://jotul-static-content.s3.amazonaws.com/usa/Current_Manuals/Wood/F400/139680_R04_Manual_F_400_NA_EPA.pdf

 

[bigealta]

air deflector follow up.

Yes i confirmed the air deflector is attached to the top of the baffle. I assumed it was part of the baffle casting but found it is a separate piece bolted to the top of the baffle.

Ok this is wrong. Sorry my bad.

As EBS says above.... the air deflector is bolted to the front of the stove above the door. (across from the baffle)

And i was also wrong thinking the baffle and secondary jet holes were 1 cast piece.
But again EBS is correct that the baffle and bent plate that has the secondary jet holes is indeed 2 separate pieces that are bolted together.

Thanks for pointing this out as i was always confused when u guys were talking about the SS secondary burner when i thought it was a cast piece.

The exhaust deflector flat plate does stand on top of the baffle as seen in the pic.

 

[bigealta]

Just to make it clear what's what.