Jotul Oslo V3 getting too hot during break in. How worried should I be?

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Pat Wiggim

New Member
Dec 29, 2020
3
Halifax NS
I'm on my sixth "break in" fire, but 3 out 6 of them have gotten hotter than they were supposed to. I'm shooting for 500 on this one, but after taking a looong time to climb to 500, next thing I know it's shot right up to 600, so I'm letting it die down. This has happened on my attempts for 200 and 400 although I eventually had success at those. I barely know if there's any point to me trying to maintain 500 since the temperature has already exceeded that several times. I'm hoping I haven't F'd the stove up, but it seems to be doing fine.... The temperatures sneaking up that high may have something to do with my 40 ft chimney and me getting distracted for 10 minutes right when it decides to take off!
 
The issue is the 40 ft chimney. Be careful opening the stove door. The draft might suck your pants off.
Sounds like you will need a key damper, maybe two, on the stove pipe.

The stove is likely fine and definitely broken in by now. Get a damper or two in the stovepipe and it should settle down. Set a timer so that you don't forget the stove at a critical time. That can do damage if left unattended for too long.
 
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That 40' chimney could definitely put a hurting on that stove. Begreen offers solid advice.
 
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As mentioned the issue may very well be the chimney length . . . and equally as important the need to pay close attention to the temps. When you start burning you may want to start shutting the air control sooner rather than later . . . at least this was the case with the second generation Oslo which did not have a cat.

That said . . . I suspect these stoves are still being built like previous generations . . . namely like Abrams tank and would not worry too much about going a little over the temp . . . especially since folks (and by folks I mean myself as well) have had these stoves well over 600 degrees while doing a regular burn.
 
The temp you can hit and run at is based on the amount of wood in the stove, as much as the draft. A little late now but that's how you do those break in fires. Your ready to burn, but I'm suggesting continue testing to get control of the burn. Just in case that 40' chimney creates a run away stove.
 
Thank you for the quick replies! Setting a timer is s great idea @begreen. I think I need to damp it down sooner as well.

I did a full burn yesterday and followed the advice about stacking it full of wood after it gets up to temperature. The great news is that with the draft I have no trouble getting it up to temperature and getting a secondary burn. I was able to have it steady at 800 for most of the day and woke up to some coals in the morning so my fears about tearing through my wood supply is allayed. In the evening when I loaded it and shut it down all the way, I was worried I wouldn't be able to maintain the secondary burn, but sure enough, after a while it kicked in.

I do think a flu damper would be helpful, but my stove back vents and most of what is exposed of the flu is the taper from 8" to 6" so I'm not sure what I'll be able to do without pulling the stove forward. In the meantime, I'm going to try and find the right time to start closing the damper and keep the temperature from running away. At one point early in the burn it did get up to 1200. It seems to climb very slowly and then it can start soaring in a matter of minutes.

p.s. I think I may have been exaggerating about the flue length. It's probably closer to 35'.
 
How are you measuring this 800, 1200? If it's possible, the stove won't like it.
 
Even 35' is a tall flue. Agreed that 800 df for the stove top is a bit hot, even for a flue temperature that's fairly hot as well. 1200 is verging on chimney fire temperatures and certainly a significant amount of heat drawn up the flue.
 
How are you measuring this 800, 1200? If it's possible, the stove won't like it.
It's measuring inside the stove... it's a thermometer that came with the stove that you insert in the upper right corner. The manual says that the secondary burner is engaged between 600-1200 so I should hope that's ok! It also says the most efficient burn is 600-800.
 
It's measuring inside the stove... it's a thermometer that came with the stove that you insert in the upper right corner. The manual says that the secondary burner is engaged between 600-1200 so I should hope that's ok! It also says the most efficient burn is 600-800.
Oh, that's right, this stove has a catalyst now. 1200 is not out of the ordinary for a new catalyst, so you should be fine. Definitely keep an eye on it when the temperatures really get low and the draft picks up even more.