Not Seeing Secondary Combustion - Osburn Inspire Stove

[Heatman]

I've been using my newly installed Osburn Inspire 2000 freestanding stove (with a new insulated SS liner) for a couple of months now, getting to know the stove and learning how to burn properly since I'm new to the game.

My stove works well and puts off decent heat, but I almost never see secondary combustion, even when using decent seasoned wood and filling the firebox up, with flue temps reaching about 600F and firebox temps reaching ~850F. Only a few times have I noticed secondary combustion taking place.

Is it normal for secondary combustion to be relatively rare, or does secondary combustion kick in in ways that are invisible.... or is there something I should be doing differently or troubleshooting?

Thanks for the help!

 

[begreen]

The fire looks good. If there is no smoke then there is secondary combustion. It is not always dramatically visible. Look up under the deflector to the back of the stove.

 

[EbS-P]

How tall is the chimney?

 

[Heatman]

How tall is the chimney?

About ~22 feet I believe

 

[EbS-P]

About ~22 feet I believe

It might need a pipe damper.

Edit.. try lighting a top down fire with lots of kindling. You should see the flames wrapping around the air stream from the secondary air holes in the beginning. If it looks like the air is trying to blow the flames out in the beginning you might have to much draft.

 

[bigealta]

It might need a pipe damper.

Edit.. try lighting a top down fire with lots of kindling. You should see the flames wrapping around the air stream from the secondary air holes in the beginning. If it looks like the air is trying to blow the flames out in the beginning you might have to much draft.

Yes Good Top down fires will get secondary air flow and then flames in just minutes. Different woods create more or less secondary flames. Pine makes Blow torch like secondary jets. Oak can be much more testy on producing secondaries depending on how you burn it and set your draft.

 

[bigealta]

"Decent Seasoned Wood" would be my 1st choice in why your secondaries are elusive. The lower the Moisture content the more secondary flames you will get has been my experience with my jotul f400.

I'm talking about 16-17% for oak and that's not even producing crazy secondary jet flames if not draft controlled correctly with my shorter chimney set up.

 

[Heatman]

Thanks for the replies all.

So I've been doing some experimenting, and tried splitting my firewood into smaller pieces and entirely packing the firebox. When I do this, the flue and firebox temps go really high (above the threshold of my thermo gun which is 750F), but I don't see any evidence of overfiring.

I do see some secondary burning in the back of the stove during this scenario, and it also looks like chimney drafts pretty strong as well, even with the primary damper all the way closed. This makes me think that a pipe damper would be helpful in some circumstances, but the problem is, my stove is installed in a weird fireplace (pic below), so operating and installing the damper would be a pain in the ass.

One thing also is that my wood isn't ideal.... some of it is around 20% while some of it is closer to 23%, and it's mostly fir. I haven't seen anyone locally in the PNW (greater Seattle area) that sells oak, except for some businesses that sell it for about $950/cord, which is sort of nuts.

 

[EbS-P]

Thanks for the replies all.

So I've been doing some experimenting, and tried splitting my firewood into smaller pieces and entirely packing the firebox. When I do this, the flue and firebox temps go really high (above the threshold of my thermo gun which is 750F), but I don't see any evidence of overfiring.

I do see some secondary burning in the back of the stove during this scenario, and it also looks like chimney drafts pretty strong as well, even with the primary damper all the way closed. This makes me think that a pipe damper would be helpful in some circumstances, but the problem is, my stove is installed in a weird fireplace (pic below), so operating and installing the damper would be a pain in the ass.

One thing also is that my wood isn't ideal.... some of it is around 20% while some of it is closer to 23%, and it's mostly fir. I haven't seen anyone locally in the PNW (greater Seattle area) that sells oak, except for some businesses that sell it for about $950/cord, which is sort of nuts.

Firebox temps should be really high to get secondary combustion. It’s not useful to measure them. Stove top temps in the same spot or flue gas temps are the best ways to measure temperature.

 

[begreen]

Thanks for the replies all.

So I've been doing some experimenting, and tried splitting my firewood into smaller pieces and entirely packing the firebox. When I do this, the flue and firebox temps go really high (above the threshold of my thermo gun which is 750F), but I don't see any evidence of overfiring.

I do see some secondary burning in the back of the stove during this scenario, and it also looks like chimney drafts pretty strong as well, even with the primary damper all the way closed. This makes me think that a pipe damper would be helpful in some circumstances, but the problem is, my stove is installed in a weird fireplace (pic below), so operating and installing the damper would be a pain in the ass.

One thing also is that my wood isn't ideal.... some of it is around 20% while some of it is closer to 23%, and it's mostly fir. I haven't seen anyone locally in the PNW (greater Seattle area) that sells oak, except for some businesses that sell it for about $950/cord, which is sort of nuts.

Seems high. Where are these temperatures being read?

If you have room to store it, there often is apple and cherry wood for sale in the area from eastern WA orchards.

 

[Heatman]

Seems high. Where are these temperatures being read?

If you have room to store it, there often is apple and cherry wood for sale in the area from eastern WA orchards.

Temps are read via thermo gun pointed at the firebox.