F55 Overnight Burns

It's the draft. Bigger temp difference creates stronger draft and burns wood quicker.

jzinckgra said:

Looks like lots of people getting the F55 judging by the posts. We're on our 2nd season with the stove and it's been a good stove, but have a couple questions about burn time. Last night was 0F and I loaded the stove, mostly with oak. Typical layout with large splits is 4 sticks N/S on the bottom, then 3 splits E/W on top of that. Let it rip for 10min or so, then turn down air in increments, ultimately until air is fully closed. There's a nice little burn, sometime with secondary combustion. I go to bed and get up at 130am and see I'm already down to a hot coal bed which yielded 4.5hrs burn. Seems really short. I load in three more pieces and oddly those lasted longer; ~5hrs. Is this typical?

A couple week ago when it was warmer, I loaded 7 splits like above and got close to 8hrs. I assume the colder weather has some affect on burn time? How does the stove know if it's colder out. Seems like it wouldn't matter. Been around woodstoves all my life, mostly my dad's, but have been burning my own stoves last few years and never really think about all the things that factor into running a stove optimally. thanks.

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Jz how big are your splits?
The outside temps as they get colder makes your chimney draw better.
I have a jotul 400 which has a smaller firebox than the f55 and I have no problem with an overnight burn. That means I have coals to relight in the morning. Is your wood dry and seasoned, below 20% moisture?

How tall is your chimney from flue to cap? And how much sticks up past the roof outside?

It's funny, I too experience "random" burn times. Last night, I loaded 3 small/medium splits of oak and 2 med/large splits of pine in my Napoleon 1401 at about 9:45. There was already a couple of mostly-burned logs in the stove and lots of coals. I loaded the stove at a stovetop temp of around 450 degrees. I let it burn at a pretty low drat for 15 minutes and then shut it all the way down at 10:00. At 6:00 this am, the stovetop was 250 degrees and there were a good number of coals; some that retained the shape of the splits. Of course flames were long gone, but with the blower on medium from the night before and 250 degrees, there was still quite a bit of heat.

I typically don't get as good of a burn as that. Usually, the stovetop is at 150 after 8 hours. The following is what I did differently last night;

1) Loaded the stove at a hotter temperature than normal. It's weird, the splits almost instantly ignited and I thought at the time that I was going to get a shorter burn; not a longer burn!

2) Used wood that had been sitting on my hearth for about 24 hours (it was drier than normal)

Just my personal observation... Hope it helps

jzinckgra said:

20' from flue to cap. Outside pipe is 13'.

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Okay, that's a that's a pretty good height. Not overly tall. Overdraft issues due to height shouldn't be in play here. Probably just the temp difference like others have indicated.

jzinckgra said:

Looks like lots of people getting the F55 judging by the posts. We're on our 2nd season with the stove and it's been a good stove, but have a couple questions about burn time. Last night was 0F and I loaded the stove, mostly with oak. Typical layout with large splits is 4 sticks N/S on the bottom, then 3 splits E/W on top of that. Let it rip for 10min or so, then turn down air in increments, ultimately until air is fully closed. There's a nice little burn, sometime with secondary combustion. I go to bed and get up at 130am and see I'm already down to a hot coal bed which yielded 4.5hrs burn. Seems really short. I load in three more pieces and oddly those lasted longer; ~5hrs. Is this typical?

A couple week ago when it was warmer, I loaded 7 splits like above and got close to 8hrs. I assume the colder weather has some affect on burn time? How does the stove know if it's colder out. Seems like it wouldn't matter. Been around woodstoves all my life, mostly my dad's, but have been burning my own stoves last few years and never really think about all the things that factor into running a stove optimally. thanks.

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Same scenario here JZ. I thinking it was my overly dry barkless maple that was yielding only 4-5hr burn times. I was hoping to find and try some seasoned oak, ash.... to see if I could extend the overnight burn. I too have been getting up between 1 and 3 to add more fuel. But after reading your post here, maybe limiting the secondary air that was posted yesterday would help us out.

My F55 will be installed hopefully next week so I could use all the operating tips I can get! this is our first stove and we are looking forward to it. I know there will be a learning curve but we're patient.
Sounds like your stove is doing well just need to "learn" the stove and make tweeks!

jzinckgra said:

I close my secondary all the way down most nights, but not until sticks are charred a bit and there is no chance for smoldering

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I do the same.

I was referring to restricting the secondary air opening under the stove.

See the Jotul F50 post. Should of started a new post.

jzinckgra said:

Oh yeah, was confusing primary secondary

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I knew you were taking about knocking back the primary air. The secondary is non adjustable.

I loaded up last night with 6 splits N/S and 1 split E/W on top. Burned about 6 hours before coaling with the stove top temp of 275. Best run so far.I pulled out my beater chop saw and cut to fit for N/S loading. The back of the stove is stepped. Going to try loading tighter tonight.

cybex said:

Burned about 6 hours before coaling with the stove top temp of 275. Best run so far.

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275 after the 6 hours or during the burn?

Knots said:

275 after the 6 hours or during the burn?

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Thats after loading 6 hours before it had drop down to 275*

cybex said:

Thats after loading 6 hours before it had drop down to 275*

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Nice. What kind of wood are you burning?

Knots said:

Nice. What kind of wood are you burning?

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This batch looks to be mostly maple. 7 splits loaded up for the night.

In my F50, I burned N/S on bottom and E/W all last winter (first year with this stove) and have been exclusively loading N/S on both layers this year... burn times have improved across the board. For what its worth.

cybex said:

This batch looks to be mostly maple. 7 splits loaded up for the night. View attachment 149888

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Just got up to check the stove. 5.5hrs now into the burn with stove temp @350*, blower operating at 75%. Back to bed.

metalsped said:

In my F50, I burned N/S on bottom and E/W all last winter (first year with this stove) and have been exclusively loading N/S on both layers this year... burn times have improved across the board. For what its worth.

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That's interesting... I always thought that N/S burning was supposed to be hotter and faster than E/W? I might give it a try too.. Although my firebox isn't very deep I have noticed there's really big difference between the burn rates of what's stuffed in the back compared to the front.

With regard to overnight burns... I've learned over time how to get them pretty consistently on my wee F3 if I want them.. although I don't do it much - don't need to very often in our winters, so it would be wasting wood. For me the key is having a good deep bed of coals on which to place the final load.... Ties in with one of JackLake's observations above, about what works for him.

Our F55 goes in next week. Our first stove can't wait!

Creekheat said:

Our F55 goes in next week. Our first stove can't wait!

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I can feel your excitement from here! And I remember how it feels.... Enjoy! I hope it all goes like a dream and that in just over a week's time you will be in The Glow. You will love every minute.

Creekheat said:

Our F55 goes in next week. Our first stove can't wait!

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You're gonna love it once you figure out how to run it. That big front glass makes for great viewing. I'm going to put mine up another foot or so on blocks for easier loading and better viewing.