Still having problems with Jotul Oslo

[firefighterjake]

I should mention that when I start up from a cold stove the first fire generally doesn't seem to really pump out the heat or get going quite so quickly . . . where I tend to notice the heat more is when I reload the stove after getting it going . . . for some reason (maybe because there is more room for wood vs. kindling) the reload seems hotter and seems to take off quicker.

That is because the stove top heats up faster than the rest of the stove body Jake. By the time you reload the stove body temp has come up to close or the same as the top so you have more iron radiating heat. And the firebox temp has stabilized so the new wood takes off faster.

This makes sense . . . glad to know it wasn't all in my head and me just imagining things . . . now if you could explain away why those pesky leprechauns are stealing my firewood every night and whether I should listen to the voices in my head it would be much appreciated.

 

[Battenkiller]

I think the white enamel gives it extra magic powers, doubling the BTUs with half the wood

Ha, ha! Yup, there's always a logical reason. ;-)

BTW, the glass has about the same emissivity (.95) as the rest of the stove, so it shouldn't be able to radiate any more heat than the cast iron can. Wish I had it in my stove, though. Makes me sad to see all these beautiful pics of nice fires and all I ever get to see is a black box.

 

[CarbonNeutral]

I think FFJ's problem is the lack of enamel..

I understand your point about the glass, but the area in front of the stove feels much warmer. Now of course I don't tend to sit behind my stove, and the sides are smaller, but is there something we're missing apart from just that value?

 

[Battenkiller]

Well, go sit behind your stove to compare. LOL

The total area of a radiating surface has to be considered. Since the front is the largest surface facing the room, it will be putting out more sensible heat. That's why bigger stoves need more clearance from combustible surfaces at the same surface temps. Plus, the front just may be hotter than the rest, particularly once the fire is well underway. I know mine can, and often does. Like I said, 1047ºF once (and who knows how high when I wasn't spying). I've had it go over 900º on many occasions, although I never saw the top get much over 800º. It really depends on where the air is flowing inside the box. I only have a rudimentary understanding of how the air flows in an Oslo, but where there is the most air and the most fuel, there will be the hottest parts of the fire.

 

[grommal]

The ideal heat range for the Oslo is 400-600 so I would say you are right where you should be. Any higher than 650 I believe is considered 'over fire' for the Oslo.

Shari

600 on the stovetop (not the griddle top) is considered the max of the normal range for the VC Defiant Encore, too. It's not just the Oslo. If the OP is comparing the temperature on the VC griddle top to the recommended corner position on the Oslo, I'd expect a big difference, since the cast iron is much thinner on the griddle.

 

[mikepinto65]

Hearthstone soapstone stoves have a lower temp limit than cast or steel stoves. The recommended operating range for the Oslo is 400-600, but it can run at 700 if you need it to without worry of overfire.

I remember having this problem when I first ran the Castine and thought something was wrong with the stove. Then temps dropped, draft and my techniques improved and hitting 650 became pretty easy. There's a learning curve with every stove. They don't drive like grandpa's Ford truck. It takes awhile to get the most out of it.

What would you say is true overfire zone for the Oslo? I have had mine to 750 once by accident with no problems/glowing. It was actually only 750 on one corner, the other corner was only at 600 (set up two thermos just to watch differences for a while).

 

[begreen]

I'd put overfire at somewhere above 850 stove top. Our old 602 ran at 750-850 on a regular basis and is still in (moderate) use. The enamel on it looks great, no sign of cracking or peeling.

 

[Nonprophet]

I'd put overfire at somewhere above 850 stove top. Our old 602 ran at 750-850 on a regular basis and is still in (moderate) use. The enamel on it looks great, no sign of cracking or peeling.

Well, I couldn't get my Oslo up to 800 if I stuffed it full of KD lumber I fear.........

I wasn't expecting a Ferrari, but I wasn't expecting a '65 VW Bug either. My Oslo stove just seems sluggish. I had another fire last night, this time trying a top-down fire. Two 4" splits of bone dry cedar (6-8% moisture content) on the bottom oriented NS for best air flow, a pile of KD 2x4 kindling (1/4"x1.5"x6") and a nice handful of shavings/kindling from bone dry cedar shakes, with 5 newspaper "bow-ties" on top. It started just fine and burned down to the cedar splits, and then just kind of fizzled--if I hadn't cracked the side door I'm sure it would have gone out........32 degree temps last night, and very dry wood, and still I had to keep fussing with it for over 2 hours (cracking the door, closing the door, adding more kindling, etc.) before I finally got a decent fire going with a good bed of coals. I realize each stove has it's little "tricks," but with a 19' stack and super dry wood and by no means being a newbie to building fires, I just can't figure out the sluggish performance of this stove. Because I bought the stove used, I'm beginning to wonder if maybe it doesn't have some kind of factory flaw that inhibits air flow--maybe that's the real reason the people sold it. I don't know, but right now this stove is feeling like it's more trouble than it's worth.............


NP

 

[begreen]

Pull the doghouse and remove the slider and vacuum out the air passage. Take an unbent coat hanger and fish around to be sure there is no debris in there. Then replace the slider and inspect the slide air control to make sure that it is seated properly and functional and has the full slider range.

 

[WOODBUTCHER]

I'd put overfire at somewhere above 850 stove top. Our old 602 ran at 750-850 on a regular basis and is still in (moderate) use. The enamel on it looks great, no sign of cracking or peeling.

Well, I couldn't get my Oslo up to 800 if I stuffed it full of KD lumber I fear.........

I wasn't expecting a Ferrari, but I wasn't expecting a '65 VW Bug either. My Oslo stove just seems sluggish. I had another fire last night, this time trying a top-down fire. Two 4" splits of bone dry cedar (6-8% moisture content) on the bottom oriented NS for best air flow, a pile of KD 2x4 kindling (1/4"x1.5"x6") and a nice handful of shavings/kindling from bone dry cedar shakes, with 5 newspaper "bow-ties" on top. It started just fine and burned down to the cedar splits, and then just kind of fizzled--if I hadn't cracked the side door I'm sure it would have gone out........32 degree temps last night, and very dry wood, and still I had to keep fussing with it for over 2 hours (cracking the door, closing the door, adding more kindling, etc.) before I finally got a decent fire going with a good bed of coals. I realize each stove has it's little "tricks," but with a 19' stack and super dry wood and by no means being a newbie to building fires, I just can't figure out the sluggish performance of this stove. Because I bought the stove used, I'm beginning to wonder if maybe it doesn't have some kind of factory flaw that inhibits air flow--maybe that's the real reason the people sold it. I don't know, but right now this stove is feeling like it's more trouble than it's worth.............


NP

NP,
Here is what I'd do as last resort. You stated in a later post that you have a decent ambient draft correct?

Make sure the insulation blanket is laid flat.
Make sure the Flue collar area is clean and has a good gasket.
Clean out stove, hook shopvac hose up to bottom rear air inlet and try to purge the stove out.

This might be a repeat but here is some info on the 2 Oslo's in the family.

Usually cruise nicely with air lever closed 75% (between 1/2 and 3/4 full of wood)
Both stoves will over fire quite easily if the air lever is left wide open (especially fully loaded on a good bed of coals)
I get short burn times and really hot fast fires loading shorties North to South.
Just the other night (was about 45 outside) I got distracted and she hit 675 3/4 full of dry Ash pretty quickly.
On a good bed of coals in the morning I get her ripping above 500 within 15-20 min.
On a cold start it takes about 30-40 min to get her ripping above 500.

I hope you can figure your Oslo out!

WoodButcher

 

[begreen]

Good tips, especially for the insulation blanket. Just for yuks, after checking all the above, leave the door to the yurt or a window flap slightly open when firing it up.

 

[grommal]

Pull the doghouse and remove the slider and vacuum out the air passage. Take an unbent coat hanger and fish around to be sure there is no debris in there. Then replace the slider and inspect the slide air control to make sure that it is seated properly and functional and has the full slider range.

+1

If the OP has strong draft and truly dry wood, yet can't get the stove going without leaving the door ajar, there's something wrong. With our Oslo and dry wood, it takes off just fine with all the doors closed. The only thing I need the door open for is to touch the match to the paper or SuperCedar, and then I can close it right away. Once warmed up, it cruises at 500-550 with the primary air control fully closed, and can be run hotter by opening the air up.

 

[Rob From Wisconsin]

I'd put overfire at somewhere above 850 stove top. Our old 602 ran at 750-850 on a regular basis and is still in (moderate) use. The enamel on it looks great, no sign of cracking or peeling.

Well, I couldn't get my Oslo up to 800 if I stuffed it full of KD lumber I fear.........

I wasn't expecting a Ferrari, but I wasn't expecting a '65 VW Bug either. My Oslo stove just seems sluggish. I had another fire last night, this time trying a top-down fire. Two 4" splits of bone dry cedar (6-8% moisture content) on the bottom oriented NS for best air flow, a pile of KD 2x4 kindling (1/4"x1.5"x6") and a nice handful of shavings/kindling from bone dry cedar shakes, with 5 newspaper "bow-ties" on top. It started just fine and burned down to the cedar splits, and then just kind of fizzled--if I hadn't cracked the side door I'm sure it would have gone out........32 degree temps last night, and very dry wood, and still I had to keep fussing with it for over 2 hours (cracking the door, closing the door, adding more kindling, etc.) before I finally got a decent fire going with a good bed of coals. I realize each stove has it's little "tricks," but with a 19' stack and super dry wood and by no means being a newbie to building fires, I just can't figure out the sluggish performance of this stove. Because I bought the stove used, I'm beginning to wonder if maybe it doesn't have some kind of factory flaw that inhibits air flow--maybe that's the real reason the people sold it. I don't know, but right now this stove is feeling like it's more trouble than it's worth.............


NP

What year is your Oslo??

 

[ansehnlich1]

I never build a top down fire in my stove, it just plain doesn't work.

I throw in 8 or 10 rolled pieces of newspaper, then 2x4 split kindling, then smaller splits, then larger splits on top. I roll 2 pieces of newspaper and put that on top of everything, light them first, then light the newspaper below.

I suggest you do the same, leave the side door cracked open, let the stove reach 300 degrees on the stovetop thermometer placed in the right/left rear corner, then close the side door, and report back to me what happens.

OR, if you already have a bed of coals, load the stove, leave the side door cracked open, let the stove reach 300 degrees on the stovetop thermometer placed in the right/left rear corner, then close the side door, and report back to me what happens.

I am convinced the Oslo is draft sensitive.....the stove operates best with a 6 inch pipe running 20+ feet straight up off the stove within the home's envelope then straight out through the roof.

Shorter length chimneys, elbows, exterior chimneys with 8x8 clay flue tiles, 8 inch piping, all have a dramatic effect on the operation of the stove.

Climate also plays a role, as warmer temps, along with heavier air masses, also affect the Oslo's operation.

Of course wood must be dry.

My Oslo is hooked into a 22ft. exterior brick chimney, 6 inch flex liner, vermiculite insulation, double wall about 2 feet up then one 90 degree elbow off the stove into the thimble. I haven't burned any oil this winter, so that tells me the old Jotul is doin' fine. I think from my time spent here on this site there are several Oslo's that may get up to temp a bit quicker than my setup, but I believe mine operates just as it was intended.

 

[grommal]

I never build a top down fire in my stove, it just plain doesn't work.

I throw in 8 or 10 rolled pieces of newspaper, then 2x4 split kindling, then smaller splits, then larger splits on top. I roll 2 pieces of newspaper and put that on top of everything, light them first, then light the newspaper below.

I suggest you do the same, leave the side door cracked open, let the stove reach 300 degrees on the stovetop thermometer placed in the right/left rear corner, then close the side door, and report back to me what happens.

OR, if you already have a bed of coals, load the stove, leave the side door cracked open, let the stove reach 300 degrees on the stovetop thermometer placed in the right/left rear corner, then close the side door, and report back to me what happens.

I am convinced the Oslo is draft sensitive.....the stove operates best with a 6 inch pipe running 20+ feet straight up off the stove within the home's envelope then straight out through the roof.

Shorter length chimneys, elbows, exterior chimneys with 8x8 clay flue tiles, 8 inch piping, all have a dramatic effect on the operation of the stove.

Climate also plays a role, as warmer temps, along with heavier air masses, also affect the Oslo's operation.

Of course wood must be dry.

My Oslo is hooked into a 22ft. exterior brick chimney, 6 inch flex liner, vermiculite insulation, double wall about 2 feet up then one 90 degree elbow off the stove into the thimble. I haven't burned any oil this winter, so that tells me the old Jotul is doin' fine. I think from my time spent here on this site there are several Oslo's that may get up to temp a bit quicker than my setup, but I believe mine operates just as it was intended.

Still seems like it must be differences in the stoves. I have two elbows, 2ft of horizontal run, and less than 15' of stack height from the thimble to the top of a clay-lined uninsulated exterior masonry chimney that has no other interior liner. Yet, top-down fires start wonderfully and I never need to even crack the door open, as long as the wood is truly dry. Makes it sound like a totally different animal from yours. What else in the system could be so different to cause this?

 

[Shari]

I never build a top down fire in my stove, it just plain doesn't work.

I throw in 8 or 10 rolled pieces of newspaper, then 2x4 split kindling, then smaller splits, then larger splits on top. I roll 2 pieces of newspaper and put that on top of everything, light them first, then light the newspaper below.

I suggest you do the same, leave the side door cracked open, let the stove reach 300 degrees on the stovetop thermometer placed in the right/left rear corner, then close the side door, and report back to me what happens.

OR, if you already have a bed of coals, load the stove, leave the side door cracked open, let the stove reach 300 degrees on the stovetop thermometer placed in the right/left rear corner, then close the side door, and report back to me what happens.

I am convinced the Oslo is draft sensitive.....the stove operates best with a 6 inch pipe running 20+ feet straight up off the stove within the home's envelope then straight out through the roof.

Shorter length chimneys, elbows, exterior chimneys with 8x8 clay flue tiles, 8 inch piping, all have a dramatic effect on the operation of the stove.

Climate also plays a role, as warmer temps, along with heavier air masses, also affect the Oslo's operation.

Of course wood must be dry.

My Oslo is hooked into a 22ft. exterior brick chimney, 6 inch flex liner, vermiculite insulation, double wall about 2 feet up then one 90 degree elbow off the stove into the thimble. I haven't burned any oil this winter, so that tells me the old Jotul is doin' fine. I think from my time spent here on this site there are several Oslo's that may get up to temp a bit quicker than my setup, but I believe mine operates just as it was intended.

I start my Oslo very different than above. Toss in a handful of noodles (wood noodles), maybe a piece or two of birch bark, and 2 or 3 pieces of kindling. Lite it. Wait about 2-3 minutes for this to catch and then fill it up. Close the door, monitor temp & when up to 400-450 start shutting it down in stages. Chimney is ss, about 13-14 feet, interior, insulated & fed through the old damper area of our fireplace.

Shari

 

[ansehnlich1]

Still seems like it must be differences in the stoves. I have two elbows, 2ft of horizontal run, and less than 15' of stack height from the thimble to the top of a clay-lined uninsulated exterior masonry chimney that has no other interior liner. Yet, top-down fires start wonderfully and I never need to even crack the door open, as long as the wood is truly dry. Makes it sound like a totally different animal from yours. What else in the system could be so different to cause this?

Yep, when I post what I did, and you live right near me (I'm in Gettysburg) and Shari there tells it like it is with her Oslo, theres GOTTA be something hangin' up the draft in Nonprophet's Oslo, AND I think even in mine. I fight mine some times from a cold start up, but once it's up and runnin' it does fine. But it is always air starved on startup.

I know my wood is dry, heck I believe Nonprophet KNOWS his/her wood is dry too. Somethin' ain't right.

 

[Shari]

Still seems like it must be differences in the stoves. I have two elbows, 2ft of horizontal run, and less than 15' of stack height from the thimble to the top of a clay-lined uninsulated exterior masonry chimney that has no other interior liner. Yet, top-down fires start wonderfully and I never need to even crack the door open, as long as the wood is truly dry. Makes it sound like a totally different animal from yours. What else in the system could be so different to cause this?

Yep, when I post what I did, and you live right near me (I'm in Gettysburg) and Shari there tells it like it is with her Oslo, theres GOTTA be something hangin' up the draft in Nonprophet's Oslo, AND I think even in mine. I fight mine some times from a cold start up, but once it's up and runnin' it does fine. But it is always air starved on startup.

I know my wood is dry, heck I believe Nonprophet KNOWS his/her wood is dry too. Somethin' ain't right.

What bothers me about some of the comments is the seemingly long time they keep their door open. Waiting, with the door open until the stove reaches 300 degrees ,could incur a 'distraction' time frame and end up with over heated stove. Also keeping the stove open until 300 degrees means bringing to stove up to a fairly high temp fairly fast - cast has to warm up slow or risk a possibility of stove damage. At least those thoughts would be my interpretation.

Shari

 

[ansehnlich1]

What bothers me about some of the comments is the seemingly long time they keep their door open. Waiting, with the door open until the stove reaches 300 degrees ,could incur a 'distraction' time frame and end up with over heated stove. Also keeping the stove open until 300 degrees means bringing to stove up to a fairly high temp fairly fast - cast has to warm up slow or risk a possibility of stove damage. At least those thoughts would be my interpretation.

Shari

Well, believe it or not, even with the side door open it can take quite a while to reach that 300 degrees.....you see, I think maybe some folks with great runnin' Oslo's and great draft tend to think of other Oslo's in terms of how "theirs" works....

I'm relating very much to Nonprophet as I think his stove runs very much like mine. He spoke of opening the side door, shutting the side door, then opening it again, and closing it, trying to get the fire going. Now it could be some other obstruction but I doubt it. I think it's poor draft, for whatever reason. Could be chimney, could be weather system, but my hunch remains that there is something intrinsic to some of these stoves that keep them from drafting as well as others.

And indeed I agree that wood burning carries with it a responsibility in that one should not walk away from a stove at any time unless his/her stove is set to that point which they are absolutely certain it will not overfire.

I'm about finished with my 3rd year burning the Oslo. It's a fantastic stove, and a great heater. Like I said, I ain't burned a drop of oil this winter