Overnight Burn setting for Jotul F400 or any other stove?

[bigealta]

I’m trying to dial in the overnight burns in the Jotul f400 castine. Working to get the maximum burn time while producing minimum creosote. Let me know what you think of this setting in the 22 second video clip Thanks!

Draft set to a bit more than 3/4 Closed.
Single Wall stove pipe at a bit over 300F at 10" above the top of the f400 outlet collar. (that's as high as i can get it and still see it).
Exterior Temp 20F.

 

[firefighterjake]

Not sure about single wall . . . but I like to have my double wall Condar thermo between 350 and 700 degrees F. My wood is good . . . very good. I typically can load it up and "close" the air all the way and still get a nice secondary action.

Can you close down the air a little more and still get a nice burn? Maybe it's me, but I'm not seeing a whole lot of secondary flames.

 

[bigealta]

Not sure about single wall . . . but I like to have my double wall Condar thermo between 350 and 700 degrees F. My wood is good . . . very good. I typically can load it up and "close" the air all the way and still get a nice secondary action.

Can you close down the air a little more and still get a nice burn? Maybe it's me, but I'm not seeing a whole lot of secondary flames.

Yeah when i close it down any more, the flames and secondares will start to snuff out, with a little more draft i get both more secondares and primary flames. I very rarely get the only secondary flame action without a good amount of primary flames.

 

[Trevor Tahclep]

That is not bad but personally want it a bit higher, note many factors come in to consideration to overnight burn rate, species of wood, humidity content, size of splits, chimney draw, wind, etc. , etc., etc., what works at home here for me may not work for you, experimenting for your setup is the best solution.

 

[bigealta]

That is not bad but personally want it a bit higher, note many factors come in to consideration to overnight burn rate, species of wood, humidity content, size of splits, chimney draw, wind, etc. , etc., etc., what works at home here for me may not work for you, experimenting for your setup is the best solution.

So i guess the real question would be is 300F on the single wall be enough to safely run it without creosote build up? To me it also seems a bit to cool. During the day i'm running at between 350-400F on the single wall with quite a bit stronger burn.

 

[Trevor Tahclep]

Personally 350° +

 

[bigealta]

Personally 350° +

Yeah that's where i like it on this stove, but it does pound thru the splits, even big fat oak. The longest burn time i can get is maybe 3 hours but really more like 2-2 1/2hrs. with good wood. I hear guys claiming longer burns but that's not really happening here. The upside is my house is pretty warm even in this cold snap 19f with 22 mph winds.(warm breeze for u guys up north.)

 

[Todd]

I think 300 external flue temp is fine, anything below 250 is getting a little cool. With my stove I don’t see any smoke out the chimney at anything over 400 internal flue temps Which is roughly 200 external. You may want to experiment at lower temps to see where it starts to smoke, it may give you a longer burn.

 

[bigealta]

I think 300 external flue temp is fine, anything below 250 is getting a little cool. With my stove I don’t see any smoke out the chimney at anything over 400 internal flue temps Which is roughly 200 external. You may want to experiment at lower temps to see where it starts to smoke, it may give you a longer burn.

so i just let it drop to 250f and it started to put some smoke out the top of the flue. I think 300 is probably min temp for this set up.

 

[EbS-P]

This is what I do. Get a good deep coal bed. Open the air all the way for 15 min. Get the coals good and hot. Stuff it tight with a piece of kindling right in the coals and anther right in front of a set of secondary baffle holes. I pack it full. Almost touching the baffle sometimes touching.

Things should light off fast. The kindling catches and keeps the secondaries going While the stove heats up. As soon as possible turn down the as much as you can. I go full closed on big load of pine and just a crack open on most other wood. I run full secondary flames. It gets hot. Now this might be a slow but makes a firebox full of charcoal that with very little air can get easy 6 hours between reloads. 8 is possible.

I don’t have any oak yet. The fast off gassing of pine keeps the secondary combustion fully engaged with minimal primary air. Coldest day of winter here. Loaded at 9:30 pm -430 am. One small split at 630. Full load at 9am. Two uglies at 530. Need to burn down some coals before I can load full again.

Wish I could chime in with pipe temps. With a full insulated liner I’m not really too concerned with flue temps. I just run by sight. I have a Auber at200 to help remind me when I walk away but I don’t run the stove by it.

Looking at your video if it was my set up I would trying for more secondary combustion. Hotter coals more wood? Run hotter before you turn it down. I probably don’t turn down soon enough but I hardly ever have smoke coming out. Neighbors never have complained.

 

[bigealta]

This is what I do. Get a good deep coal bed. Open the air all the way for 15 min. Get the coals good and hot. Stuff it tight with a piece of kindling right in the coals and anther right in front of a set of secondary baffle holes. I pack it full. Almost touching the baffle sometimes touching.

Things should light off fast. The kindling catches and keeps the secondaries going While the stove heats up. As soon as possible turn down the as much as you can. I go full closed on big load of pine and just a crack open on most other wood. I run full secondary flames. It gets hot. Now this might be a slow but makes a firebox full of charcoal that with very little air can get easy 6 hours between reloads. 8 is possible.

I don’t have any oak yet. The fast off gassing of pine keeps the secondary combustion fully engaged with minimal primary air. Coldest day of winter here. Loaded at 9:30 pm -430 am. One small split at 630. Full load at 9am. Two uglies at 530. Need to burn down some coals before I can load full again.

Wish I could chime in with pipe temps. With a full insulated liner I’m not really too concerned with flue temps. I just run by sight. I have a Auber at200 to help remind me when I walk away but I don’t run the stove by it.

Looking at your video if it was my set up I would trying for more secondary combustion. Hotter coals more wood? Run hotter before you turn it down. I probably don’t turn down soon enough but I hardly ever have smoke coming out. Neighbors never have complained.

So i'll try it this way. Thanks

What i've been doing is putting on fairly large size oak splits on decent coals, but not pre fired for any time. Usually only 3 large splits which takes up a large amount of space in the firebox. These tend to smother the coals and i get smoke and slow starting.

Then i also try some smaller splits on the coals and that works better, but the jenga game gets sketchy as the big oak goes on top.

The best results are when i put 2 E/W sleepers on the bottom, then some decent size splits, then another set of sleepers and a second row of splits creating nice airflow gaps. This works the best for me but it just becomes a regular burn that only lasts 2-3 hours max even with the draft closed as far as i can while keeping secondaries going strong.

With starting and burning so many top down fires that create excellent starts and full clean burns, the reloading and overnight loading has usually been disappointing as they mostly seem to make way too much smoke, with limited staying power.

Thanks for posting your set up. Look forward to getting this dialed in.

 

[bigealta]

Do you Jotul burners put splits over the dog house or just up to it? I try not to go on top of the dog house and get to close to the ceramic glass on the door, but maybe that is too cautious?

 

[bholler]

So i guess the real question would be is 300F on the single wall be enough to safely run it without creosote build up? To me it also seems a bit to cool. During the day i'm running at between 350-400F on the single wall with quite a bit stronger burn.

Yes 300 is plenty if the liner is insulated

 

[EbS-P]

So i'll try it this way. Thanks

What i've been doing is putting on fairly large size oak splits on decent coals, but not pre fired for any time. Usually only 3 large splits which takes up a large amount of space in the firebox. These tend to smother the coals and i get smoke and slow starting.

Then i also try some smaller splits on the coals and that works better, but the jenga game gets sketchy as the big oak goes on top.

The best results are when i put 2 E/W sleepers on the bottom, then some decent size splits, then another set of sleepers and a second row of splits creating nice airflow gaps. This works the best for me but it just becomes a regular burn that only lasts 2-3 hours max even with the draft closed as far as i can while keeping secondaries going strong.

With starting and burning so many top down fires that create excellent starts and full clean burns, the reloading and overnight loading has usually been disappointing as they mostly seem to make way too much smoke, with limited staying power.

Thanks for posting your set up. Look forward to getting this dialed in.

I think clean burning gets more heat into to the room than letting smoke go up the stack even if it’s a bit shorter burn time. I try not to stack on dog house but sometimes it happens. It’s an odd shape fire box. I looked in once and realized I only was able to get two splits in. Odd shape makes great secondary burning flames.

 

[bigealta]

The best results are when i put 2 E/W sleepers on the bottom.

Sorry meant North /South sleepers not E/W.

 

[firefighterjake]

Do you Jotul burners put splits over the dog house or just up to it? I try not to go on top of the dog house and get to close to the ceramic glass on the door, but maybe that is too cautious?

Up to it . . . the "glass" should be fine with something right up against it even, but I like to try to keep it clear . . . keeps the glass a bit cleaner and I figure I don't need that much extra fuel.

 

[bigealta]

Ok here's what i got last night. 17 minutes to setting draft for overnight burn 350 single wall temp. Oak and a piece of cherry.
Load 9:10p, 9:16, 9:21, 9:26, 9:27, 9:33, 9:33.

 

[bigealta]

Here is the burn rate set at 17 minutes after overnight load. Pipe temp is running steady at 350f on single wall 10" above top of jotul outlet collar. Draft set a bit more then 3/4 closed. Oak and a piece of cherry. This seems to be a decent burn rate for long burn. Appreciate any comments opinions on how to dial this in. This burn left about 2 handfuls coals to Reload at 2:30A. Thanks

 

[Todd]

Do you have larger splits? I bet 4 larger splits that just about fill the fire box would burn longer. Rake all the coals forward, pack the largest split in the lower back, the smallest one in front on top of the coals then pack in from there.

 

[bigealta]

Do you have larger splits? I bet 4 larger splits that just about fill the fire box would burn longer. Rake all the coals forward, pack the largest split in the lower back, the smallest one in front on top of the coals then pack in from there.

Yes, when i do that the fire gets smothered and it becomes a smoke machine for far longer than i'de (and my close neighbors) like. That's always been my problem. I just can't seem to get the same low smoke fires that i get with just doing top down starts. I realize that a top down set up is not the same as an overnight load but i'm trying to get it at least closer. I'm thinking i just need to make sure there is good airflow between the splits (which is at odds with a tight long burn pack) and just be happy with a cleaner shorter burn vs. a dirtier longer burn.

 

[EbS-P]

Here is the burn rate set at 17 minutes after overnight load. Pipe temp is running steady at 350f on single wall 10" above top of jotul outlet collar. Draft set a bit more then 3/4 closed. Oak and a piece of cherry. This seems to be a decent burn rate for long burn. Appreciate any comments opinions on how to dial this in. This burn left about 2 handfuls coals to Reload at 2:30A. Thanks

M

Yes, when i do that the fire gets smothered and it becomes a smoke machine for far longer than i'de (and my close neighbors) like. That's always been my problem. I just can't seem to get the same low smoke fires that i get with just doing top down starts. I realize that a top down set up is not the same as an overnight load but i'm trying to get it at least closer. I'm thinking i just need to make sure there is good airflow between the splits (which is at odds with a tight long burn pack) and just be happy with a cleaner shorter burn vs. a dirtier longer burn.

Take two loads worth of wood and stack it near the stove for 24 hours. I found that moisture content effects my burn a lot.

 

[Todd]

Yes, when i do that the fire gets smothered and it becomes a smoke machine for far longer than i'de (and my close neighbors) like. That's always been my problem. I just can't seem to get the same low smoke fires that i get with just doing top down starts. I realize that a top down set up is not the same as an overnight load but i'm trying to get it at least closer. I'm thinking i just need to make sure there is good airflow between the splits (which is at odds with a tight long burn pack) and just be happy with a cleaner shorter burn vs. a dirtier longer burn.

Ok, maybe there’s not enough coals for a quicker take off? When I had an E/W burning stove (Woodstock Keystone) and there were less coals than I’d like for a reload I’d either place a couple pieces of kindling on top of the coals to help catch quicker and help elevate the lager splits or I’d just burn more kindling before adding splits to build up a better coal bed.

 

[bigealta]

Take two loads worth of wood and stack it near the stove for 24 hours. I found that moisture content effects my burn a lot.

Yup i always do that. To be fair to the stove, some of the splits were short maybe 15-16". I'll try a bunch more with different set ups of full length 18+" splits. It could be moisture, but i do get very good burns with air space between splits. It's when they are packed tight and cover the coals like a blanket that i'm no good at setting up. And maybe i'm just to picky about making more smoke than i think should be acceptable.

 

[bigealta]

Evan - thanks again for the "piece of kindling in front on the coals and on top at the baffles". That did work better than my other "pack it tight for overnight" loads.

 

[EbS-P]

I have tried raking a trench in the ash and coals right down the middle all the way to the back. but it doesn’t line up with the air holes to well. I generally leave a lot of ash In the box too. Keeps the heat better.