Jotul Olso , how hot is too hot , quickly?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

Sootfoot

New Member
Mar 16, 2015
40
Ontario, Canada
When starting a fire, I use the top down method. From a cold stove, I can get a top temperature of around 450F in less then 10 minutes. Corners read 80-100F. This is with all doors closed and air control wide. Is this too hot too quick? How does the jotul take to high stove top temps quickly? Is this stove easy to crack? I know cast wants to heat up evenly, but wondering as I'm getting better at starting fires and getting quick heat. Thanks

Ps...... When I read a stove top temp of let's say 850-900F .... Very high..... And the corners read around 625-700F..... Is this too hot to run my jotul. Last question, the stove top temp must be inaccurate because of the dual burn tubes just a glowing red pumping out 1000F +?

Thanks again


Sootfoot
 
That sounds very hot. My vc doesn't get over 500 but once in a blue moon and that already cooking us out of the room.
 
When I start up my cold Mansfield, I'll let it heat slowly until about 300F .Takes about a half hr. The soapstone can crack if heated too fast. Controlled heating and expansion will give longevity to the stove.
 
Do the five dollar bill test to make sure your door is sealing properly.are you burning softwood or hard.
 
Do the five dollar bill test to make sure your door is sealing properly.are you burning softwood or hard.

Soft & hard. But for starting fires always soft. I split up some 2x4 & 2x6 to wafers tapered down to 2x2 size as sleepers. Once this gets to coals I'll either throw more soft in and keep an eye on temperature or throw some hard in depends on how cold it is.
 
Try with just a load of hard wood and see how it goes.it might just be your door is not sealing properly
 
I have a jotul f400. Optimal temp is between 400-600 and if anything is glowing you run the risk of a house fire. I never let my stove get above 600. Use the air control to get the temps under control. Like Brad said, do the dollar bill test to make sure your door seal is ok, and if anything glows red shut the air control totally.
 
  • Like
Reactions: CentralVAWoodHeat
Try with just a load of hard wood and see how it goes.it might just be your door is not sealing properly

Well to be honest, that's not really what I'm concerned about. I can easily slow down the burn with the air control, I have no issues with not being able to control my temps. I'm just wondering if reaching my temps that quick is possibly damaging the stove, or reducing it's life.
 
I have a jotul f400. Optimal temp is between 400-600 and if anything is glowing you run the risk of a house fire. I never let my stove get above 600. Use the air control to get the temps under control. Like Brad said, do the dollar bill test to make sure your door seal is ok, and if anything glows red shut the air control totally.

Well the secondary burn tubes will glow red easily, the stove itself hasn't ever.
 
Well to be honest, that's not really what I'm concerned about. I can easily slow down the burn with the air control, I have no issues with not being able to control my temps. I'm just wondering if reaching my temps that quick is possibly damaging the stove, or reducing it's life.
Yes it will reduce the life of the stove............
 
My secondary burners have never glowed red. As far as heating up too fast, I can't speak to that but I figure our stoves can deal with this way better then a soapstone stove.
 
  • Like
Reactions: CentralVAWoodHeat
If it's not out of control then make sure you turn your air down quicker,stoves can handle the heat once in a while but if it's everytime you start your going to damage stove.
 
If it's not out of control then make sure you turn your air down quicker,stoves can handle the heat once in a while but if it's everytime you start your going to damage stove.

Ok thanks. Will definitely keep an eye on starting temps. I do think I have drafty side door, gasket probably needs to be replaced
 
My secondary burners have never glowed red. As far as heating up too fast, I can't speak to that but I figure our stoves can deal with this way better then a soapstone stove.
I also run a Jotul F400 and have never got glowing burn tubes even during periods of slight over firing.
 
Have you read your manual as far as 1. what temp range you should be burning at, 2. where you should be measuring your temp and 3. how & when to shut down your air?

The answers to the above questions are in your manual. Other stove owners with different make/models of stoves will have different manufacturers recommendations - follow your manufacturer recommendations.

(In my 5th year of burning my Oslo 500.)
 
I can get a top temperature of around 450F in less then 10 minutes. Corners read 80-100F. This is with all doors closed and air control wide. Is this too hot too quick?

I don't think that's really a problem, but running it at 900f center and 700f corners probably is, if done regularly for extended periods. Warping could be a problem for parts of some stoves... the cast baffles on the F600, for example, are prone to warping.

Damage to cast iron more generally comes from thermal shock, but ten minutes is not really a shock. If I put my cast iron skillet on the gas stove and had to wait ten minutes to get it to 450f for fear of cracking it, I doubt I'd ever cook with cast iron.
 
I've heard folks who have had red glowing secondary tubes . . . but I cannot recall anyone that has had this with a Jotul . . . including myself.
 
  • Like
Reactions: CentralVAWoodHeat
I've heard folks who have had red glowing secondary tubes . . . but I cannot recall anyone that has had this with a Jotul . . . including myself.
I looked up the manual for the Oslo and it's the same as the castine. Optimal is 400-600. Any part of the stove glows red is bad and never open the ash door during a fire (even though I do for short bursts to get things going occasionally) otherwise you run the risk of cracking the stove.
 
  • Like
Reactions: firefighterjake
I would think a stove top temp of 450 in 10 minutes is too quick as the rest of the stove is probably a lot cooler. And I think if the secondaries are glowing red they are too hot. I know I would be nervous. I've never seen that on my F400.

Those 2x4's go up fast and hot (maybe too fast in a stove), you're probably concentrating a lot of heat on the secondaries. If the stove top is 450 in ten minutes those secondaries have to be a lot (a lot) hotter in the same time.
 
When researching secondary burn tubes, I discovered that most stoves will glow the tubes. They are typically thin wall stainless and can take the heat. My stove won't give continuous secondary burn until the tubes are glowing or close to it....

Hell my thick wall steel tubes and 3/16 baffle glow on a regular basis... Keep in mind secondary combustion air needs to be in the 1200° range to ignite the gasses from what I've researched.

Now I would slow the startup burn down a bit and let it come up to temp slower to prevent warping/cracking.

As far as safe temps... Go with your manual's specs.
 
I looked up the manual for the Oslo and it's the same as the castine. Optimal is 400-600. Any part of the stove glows red is bad and never open the ash door during a fire (even though I do for short bursts to get things going occasionally) otherwise you run the risk of cracking the stove.
I think the biggest danger in opening the ash door to get a fire going is what happens when it breaks or failes at this moment. Ever have an ash door gasket fall off at this critically-bad time? What will you do when your latch breaks, and you have a full load just taking off?

Some might deflect this question by saying the same could happen with your main / loading door, but you can burn most stoves with the doors open wide (screen for ember protection) without damage. You can't say the same for an ash door.
 
I think the biggest danger in opening the ash door to get a fire going is what happens when it breaks or failes at this moment. Ever have an ash door gasket fall off at this critically-bad time? What will you do when your latch breaks, and you have a full load just taking off?

Some might deflect this question by saying the same could happen with your main / loading door, but you can burn most stoves with the doors open wide (screen for ember protection) without damage. You can't say the same for an ash door.
I think the biggest danger in opening the ash door to get a fire going is what happens when it breaks or failes at this moment. Ever have an ash door gasket fall off at this critically-bad time? What will you do when your latch breaks, and you have a full load just taking off?

Some might deflect this question by saying the same could happen with your main / loading door, but you can burn most stoves with the doors open wide (screen for ember protection) without damage. You can't say the same for an ash door.


Never thought about that. I'm sure I would open the main door also to regulate pressureand then figure out what I'm going to do. Hopefully I keep the stove on good enough shape that the seals won't randomly fall off. But anything a possible.
 
If the stove top is 450 in ten minutes those secondaries have to be a lot (a lot) hotter in the same time.

Well, tubes are certainly going to be hotter, as they are inside the firebox... but in startup, I lot of the flame/heat is getting pushed past the baffle and right into the center plate on its way to the flue. So one would expect that spot to get much hotter than the rest of the stove exterior, much quicker.

Consider also how hot the flue itself gets in only several minutes after startup with the air wide open. I would think the tubes actually reach a higher temp a bit later, after the air is partly shut down, when the secondaries really kick in and less heat is pushed up the flue.
 
I think the biggest danger in opening the ash door to get a fire going is what happens when it breaks or failes at this moment. Ever have an ash door gasket fall off at this critically-bad time? What will you do when your latch breaks, and you have a full load just taking off?

Some might deflect this question by saying the same could happen with your main / loading door, but you can burn most stoves with the doors open wide (screen for ember protection) without damage. You can't say the same for an ash door.
The most common problem happens even when nothing appears to go wrong. The forge-like temps under the grate and center of the base cause it to expand rapidly. The surrounding metal, not as rapidly. The result is a very expensive base replacement, not covered under warranty ---

Jotul base crack.jpg Jotul base crack2.jpg Jotul base crack3.jpg
 
The most common problem happens even when nothing appears to go wrong. The forge-like temps under the grate and center of the base cause it to expand rapidly. The surrounding metal, not as rapidly. The result is a very expensive base replacement, not covered under warranty ---

View attachment 168805 View attachment 168806 View attachment 168807


So if a base was to crack like that, when using the stove anyway the cast should expand and almost seal the crack wouldn't it? Or is a hair line crack still enough to suck a dangerous amount of air , potentially causing a house fire? I know my old pacific energy vista had a few small cracks in the front frame around the door , but when using the stove ( before replacing it with my olso) the cracks would contract to the point of near undetectability

Sootfoot
 
Status
Not open for further replies.