Stove wants to over fire every night

[Revturbo977]

im new to burning with a jotul f400. Almost every night this thing wants to take off . I'm not sure what I'm doing wrong. I'll have a good bed of coals with the stove top at 350. I fill the box and let it get going for about 20 min. Then I back of the damper till it's closed . Hour later the stove is trying to push past 700 like crazy. I can't control this thing . Help

 

[claydogg84]

It is touching 700 with the air completely off?

 

[JTRock]

Yea that seems odd that it would take off with the air choked off

 

[Revturbo977]

Yes sir. From what I understand the air is never completely off even with the damper all the way down. It just did this again 5 minutes ago. Thankfully it burned most of the gasses in the wood out before it went past 700 and is starting to back down

 

[bholler]

how high is your stack what wood are you using how big are your splits ect?

 

[begreen]

Let the coal bed burn down a bit further for 20-30 minutes by raking forward toward the door then opening up the air 50%. After refilling, turn down the air sooner. 10 minutes should work with dry wood.

Also, what size are your splits?

 

[claydogg84]

You must have an incredible draft? I'm uncertain as to what else to blame unless you have a ton of bad gaskets feeding the stove air. Have you done a gasket check with it running?

 

[Revturbo977]

I'll fill it just below the baffles . My splits are medium I suppose. Maybe 3-4 inches at their thickest

 

[Revturbo977]

I rake them forward the best I can but this stove being kind of small, I still end up with wood on the coals .

 

[bholler]

How tall is your chimney and have you checked for leaks?

 

[Revturbo977]

Everything is brand new. From the stove to the thimble it's around 6 feet. Then 11 feet up from the t

 

[bholler]

So are you saying it is 6'up and then 11' more or 6' horizontal to a thimble and then 11' up? Either way it should not be overdrafting. I would try everything begreen said in addition to checking for leaks just because its new doesn't mean there could not be a loose door latch or something

 

[Thislilfishy]

My stove is desperate to do this as well (different stove). I have very dry wood and a tall straight chimney with tons of draft. A flue damper would help control this, but for the time being I've put a magnet over the secondary intake, making it about 3/8" smaller. I still see high flue temps but it's far less peaky. I'm waiting on a stovetop thermometer to verify that this is working and will likely get a flue damper to control it better. Of note, I tend to put one wet split with a load of my regular dry wood, this also does a very good job of keeping the temps down, but it doesn't seem to burn as completely.

Ian

 

[begreen]

I'll fill it just below the baffles . My splits are medium I suppose. Maybe 3-4 inches at their thickest

Some wood on the coals is ok. You just don't want 2+ inches of coals under the wood. The F400 works well with splits in the 6" thick range. 3" is a small split. Thinner splits will burn more quickly, but you can slow them down by packing them tighter as you reload the stove. But be sure to burn the coal bed down a bit more and close the air off sooner. And don't panic. 700-750F is a little exciting, but it's not going to harm the stove.

PS: Be sure the ash pan door is closed tightly. Ash can build up behind the ash pan and push it forward, preventing the ap door from closing correctly. Clean out behind the ap regularly to prevent this.

 

[MountainStoveGuy]

The f400 is pretty well known around here to be draft sensitive. It takes a pretty good chimney to run the darn thing (at least 16 feet at altitude). Like begreen said, make sure that ask pan is tight and also check that the primary air control didn't come loose in shipping. In the front of the stove there is a " dog house" with two bolts. Behind that is a slide that diverts the air. It should be connected to the lever in the front of the stove.

 

[Cory S]

700-750* means the incoming air is shutdown enough to keep more heat in the firebox, but yet still getting a little too much air from somewhere. Also, use another thermometer/thermocouple/IR reading to compare. Like mentioned 700-750* isn't detrimental, but if you are going above an honest 900* for extended periods of time, things could warp, etc. I constantly hit stovetop temps around 700* during mid burn. Best heat ever when heating two floors and 1900sq ft total living area.

 

[Revturbo977]

Possibly my first problem is my coal bed is too large. I didn't think its that sensitive to it but I'll try burning It down farther before I fill it. Durning the day when I'm home I put a log right on the coals and it's burns 1 every 2 hours and obviously this isn't an issue because there isn't as much fuel in the stove . I'll check for leaks, but I have a feeling I just have insane draft. I love way up on a hill and the wind seems to just pull air through the stove. I can get this thing started by lighting a dry split with one match some days when I'm being lazy with just the damper open.

Thanks everyone

 

[branchburner]

. My splits are medium I suppose. Maybe 3-4 inches at their thickest

Yes, I would also term those "small." If they were super dry, on a full load of those I think many stoves with good draft might push 700f early in the burn... I know mine would. In fact, my rear burn chamber (different than your Jotul) would likely push 800f, but I wouldn't even consider that an overfire unless it was holding that temp for extended periods. While going a bit over 700f may be "burning hot" I think of "overfire" as at least 800f, and only when you push 900f as a point where you are harming the stove.

If the stove hits 700f for only a very short time, but quickly returns to a cruising temp of 500-600f for a good long burn, I wouldn't be worried... I'd be happy.

 

[Revturbo977]

Well the stove hits 700 in the morning then I back it off and it esaly returns to the 550 range. At night it's not controllable . I should be more clear on my splits . They are a mix in size. Some are in the 3-4 and others are 6-7. I try to mix them. I'll try to save the larger splits for the over night runs.

I think my issues are a few things.
First I think my wood isn't seasoned perfectly so I know it has an issue burning well. I tend to load the box with it still fairly hot because I know it won't struggle to light. That said filling it at night , even with the damper backed off , the load will take off at some point. I woke up once with a secondary burn and it was at 750 with the damper closed. I suppose I cought it just in time and don't think it was running there for long . I'm going to need to have to load it in the evening with less coals and just let it smolder more I think.

 

[OhioBurner©]

My Jotul tends to get close overfire as well, but your 700F I wouldnt call overfire. I'd say I hit that everytime with a good full load, I'd say thats pretty normal. I'm not sure how the F400 compares but my C550 I guess the air is till open quite a bit when its all the way in the minimum position. Some have taken a grinder to the control to allow it to go less. In my other wood stove I can easily choke out the fire by cranking it down. Heck I usually cant move the draft control past half way without choking it out. The 550 Rockland no way, at least once it gets much over 400F is the draft control going to slow it down unless I'm burning crappy wood. I do have a duravent chimney around 22' I think.

 

[bholler]

Sounds like an air leak to me but i dont know the stove well. But getting over 700 with air closed all the way and wet wood that would be my first place to look

 

[Revturbo977]

Sounds like an air leak to me but i dont know the stove well. But getting over 700 with air closed all the way and wet wood that would be my first place to look

I looked everything over. I don't think so. It won't do it during the day when temps are warmer. At night when it's cold I thinks it will still pull air in. I believe I'm just loading it too hot. It was mentioned above not to load on 2 inch coals and I have done that, even when they are raked forward

 

[jophysx]

Even if you are loading it a little too hot, you want to feel like you have some control. My insert used to be the same way. It felt like I had very little control with the primary air. The stove seemed to have a mind of its own. I found my door was a little out of adjustment. Fixing that helped a lot. This year I blocked off the auxiliary air port too. Now I can kill the fire completely if I shut the primary completely. Even if it's running at 700F. I like having that level of control.

I think these auxiliary air ports are not a good feature for the wood-burning enthusiast. Maybe you need them for people who just burn casually. But for people on this forum who are burning all the time, and know how to adjust things to get efficient burn, they just make the stove less controllable.

 

[Revturbo977]

The last foot of my chimney pipe is turning rainbow blue. Not sure if this is linked or not. It's very windy where I live

 

[webby3650]

The last foot of my chimney pipe is turning rainbow blue. Not sure if this is linked or not. It's very windy where I live

The pipe turning colors is normal. It seems to be more prevalent with some cap types.
I think what you are experiencing is normal for a non cat, especially a Jotul. They love to run! I've had a bunch of Jotuls, they love to rock out if reloaded while the stove is still hot! I would reload a hot stove right before bed, but I would leave the air turned all the way off. It seemed to behave itself this way. Give it a try.