Stove top temps

[fatrabbit]

After reading some older posts on Jotul stove temps I feel somewhat better, but still have some questions .I start the stove up, get it ripping and back down the air halfway when it hits 475 or so on my Rutland stovetop thermometer . At this point it takes off and even with the air backed all the way down it still burns at 375- 400 . Is it normal for the stove to burn that high with the air all the way to the left ? I have heard some say they regularly burn at 600-650. Is this a good temp for the Jotul 600 ? Dont want to overfire but also dont want to waste wood.

Any answers from other f 600 owners.

 

[begreen]

What you are seeing is secondary combustion. It is normal. The stove is burning off the wood gasses. Depending on the amount of fuel, this can go on for 30-60 minutes. Don't worry about a stove top temp of 600-650. It can handle those temps.

 

[My Oslo heats my home]

I agree with Green, it's normal. The Jotul stoves are workhorses and the secondary burns are incredible. Enjoy

 

[pen]

sounds like you've got the trifecta: 1. a good stove 2. good dry wood 3. a good draft.

congratulations and enjoy.

pen

 

[fatrabbit]

Thanks guys, that secondary really is cool to watch.

 

[firefighterjake]

After reading some older posts on Jotul stove temps I feel somewhat better, but still have some questions .I start the stove up, get it ripping and back down the air halfway when it hits 475 or so on my Rutland stovetop thermometer . At this point it takes off and even with the air backed all the way down it still burns at 375- 400 . Is it normal for the stove to burn that high with the air all the way to the left ? I have heard some say they regularly burn at 600-650. Is this a good temp for the Jotul 600 ? Dont want to overfire but also dont want to waste wood.

Any answers from other f 600 owners.

Not a F600 owner, but I have its brother the F500.

Yes . . . I find that 450-650 degrees F are some good temps for the stove.

I am a bit surprised to not see your stovetop thermometer actually increase when you start backing down the air . . . the reason being less air is going up the flue and the description of the fire taking off sounds like secondary combustion . . . which often results in the temp on the stove top increasing a bit.

Don't worry too much about the temps . . . I mean you still should keep an eye on your stove top temp and flue temp . . . but at 400 degrees F you've got a long way to go before you approach the over fire temp.

Sounds like you're actually doing everything right . . . and you have good wood.

 

[fatrabbit]

F.F.J.: The thing is when I back it down it does go up, I then get paranoid and back it down all the way. With the air all the way closed it still goes at about 375-400. From what I have read here though It sounds as if that is normal. Im burning two year old ash and red oak. I guess I was just paranoid about overfiring.

 

[begreen]

A more common problem with new burners is burning too cool. You will see this in frequent darkening of the glass. Take her up another 100 degrees and be happy.

 

[firefighterjake]

F.F.J.: The thing is when I back it down it does go up, I then get paranoid and back it down all the way. With the air all the way closed it still goes at about 375-400. From what I have read here though It sounds as if that is normal. Im burning two year old ash and red oak. I guess I was just paranoid about overfiring.

Oh that's good . . . that's the way it should work . . . as you turn down the air the stove top temp usually will increase . . . but be aware that as you close it down further (which is a good thing for longer burns) you may see the temp increase even more since you are effectively reducing the draft and the flow of air in the stove and up the flue.

This is counter-intuitive to newbies and old veterans of pre-EPA stoves. Folks who are new figure that if you're closing off the air this would be like reducing the amount of gas you would give a car . . . and pre-EPA stove vets grew up or learned that to get a long burn on their pre-EPA stoves you dampered down and the resulting smoldering fire would reduce its heat load and have a long burn . . . the negative being that the fire smoldered, there was incomplete combustion and many a chimney got full of creosote.

If you're closing down the air most of the way to all of the way and things are good in terms of temps and enough air for combustion you should hopefully see a continued secondary combustion and the stove top temp should say around the same or increase a bit more . . . if you close off the air too much and the fire either starts to die off and the temps start to decrease then either your stove isn't quite hot enough, your wood isn't quite seasoned enough or you simply cannot shut down your air control all the way.

In my first year of burning the best I could do with semi-seasoned wood was to reduce the air control to the quarter mark . . . at that point I would have a sustained secondary burn . . . if I reduced the air more the fire would start to go out, the glass would blacken up and the stove top temp would drop. In my second year with better wood and a better understanding I was able to reduce the air control to "nothing" (technically it is at least always partially open) . . . and the result with longer burns and more heat.

 

[oldspark]

I would just go by the flue temp, If I back down the primary air the flue temp goes down, would this not work and be more in tune with what you want to see.

 

[fjord]

Non catalytic EPA engineered wood stoves like Jotuls are designed for clean, efficient burns. Unlike our older wood stoves,
primary air cannot be damped far down to shut off the air completely, OR opened fully for uncontrolled burns. Some call them "mommie" controls: you can't open the air fully open,
or shut it down completely. It has a range for clean burns: not too high, not too low. Like mommie says.
IF the primary air (that lever) is as far down as it will go, AND you have a top temp of > 650 F to > 700 F there is an air leak.
Secondary air is regulated at the rear, and is "automatic".

For our cat stoves ( like my Encore ) the stove can over burn with the air fully open, yet not shut down fully closed. It takes somwhat more finesse and fuss. It's why
the non cats were designed because of user complaints and mal- and mis- use.

We use two for 24/7 heating in two similar areas: one cat, one non cat. We prefer the cat for long clean burns with LESS wood. The non cat for ease of use and maintenance.
Your mileage will vary. Enjoy the Jotul.....we do.

 

[begreen]

That depends on the stove and how hot it is. With a full recharge on a full bed of coals, our stove will peak at 650-700 for a good hour or more. No leaks for sure. It just has a big fire box and a lot of outgassing in that circumstance.

 

[fjord]

That depends on the stove and how hot it is. With a full recharge on a full bed of coals, our stove will peak at 650-700 for a good hour or more. No leaks for sure. It just has a big fire box and a lot of outgassing in that circumstance.

Clarifying: " > " is "greater than" . So if the stove top temp is not higher than around 700 F, it's a good safe burn. Most EPA steel and cast non cat wood stoves are designed for top plate temps not much higher than 700 F.
It is difficult to get an Oslo much higher than 700 F with a full load of hardwood, and no other openings other than primary and secondary air. Cracking a door or ash pan door WILL get any beast overheated. Not good practice, except with a hard starting load such as unseasoned, or wet splits. The cat Encore on the other hand ( and pre-EPA stoves such as the famous Jotul 602, Lange, or Tempwoood ) CAN easily get glowing with a fresh load and the air wide open. It is exactly why the non cats were engineered for controlled air.

Never heard tell of outgassing.

 

[fatrabbit]

So which is better, stove top or pipe thermometer ? I have a basic rutland magnetic stove top unit that is positioned on the corner (as per jotul). I have double wall stove pipe though. Should I try and get a probe type unit and drill a hole ? What is a good flu gas temp ?

 

[oldspark]

So which is better, stove top or pipe thermometer ? I have a basic rutland magnetic stove top unit that is positioned on the corner (as per jotul). I have double wall stove pipe though. Should I try and get a probe type unit and drill a hole ? What is a good flu gas temp ?

I think both are very important especially when you are new at it or have a new stove, so one for the stove top and one for the flue and enjoy the safe heat, before long you will be an expert with your stove.

 

[begreen]

Jotul recommends stove top and that is how we ran them for years. Now we also have a flue thermometer. It's another data point, but not critical. I like it because it teaches me more about how I am burning. But if you just have one, it's the stove you're trying to not overfire.

 

[oldspark]

Jotul recommends stove top and that is how we ran them for years. Now we also have a flue thermometer. It's another data point, but not critical. I like it because it teaches me more about how I am burning. But if you just have one, it's the stove you're trying to not overfire.

What about way too high a flue temp, I would think this would be a concern, is it possible to over a stove with a medium flue temp?

 

[oldspark]

Now that I get to thinking about it, if I go by stove top temp only I am going to have surper high flue temps before the stove ever gets to overfire condition, so for me it is very important to keep an eye on the flue temp.

 

[fjord]

Jotul recommends stove top and that is how we ran them for years. Now we also have a flue thermometer. It's another data point, but not critical. I like it because it teaches me more about how I am burning. But if you just have one, it's the stove you're trying to not overfire.

What about way too high a flue temp, I would think this would be a concern, is it possible to over a stove with a medium flue temp?

No need for extra data....unless it's fun. The stoves are engineered for stove TOP temps for use.
Flue temperatures should be much higher than the stove surface for combustion of exhaust gases.
When you're heating with wood, just do it. Or, One can play with all kinds of fun tools that will satisfy the compulsive in you: lasers, temp guns, flue probes, moisture meters, 80cc chainsaws, 50 ton splitters, etc......
Some don't have the time to bother. We harvest, skid, split, stack, burn. Repeat. It's a lifestyle.

 

[oldspark]

Been burning wood for a long time and knowing what the flue temp it for saftey reasons not fun and has been for ever!

 

[fjord]

Been burning wood for a long time and knowing what the flue temp it for saftey reasons not fun and has been for ever!

Your choice.

But, no real need for flue probes. EPA stoves are engineered for users to monitor temps ON the stove: not overheating, not smouldering low. When we finally got a 'real' tech stove in the later 70's, Vermont Castings had plant and dealer programs for customers to burn right and buy. Going to a seriously engineered stove like the Vigilant and Defiant then was an educated joy. Previous stoves: Ashley, Fisher, Morso 2BO, Lange, Jotul 602, Tempwood. Yes, A true compulsive wood stove freak. :bug:

Safety is burning cleanly, efficiently: get the splits combusting first, then damp the air, no matter whch technology you have--pre-EPA, cat, non-cat. Could take some time for the load to gas off for combustion.
Seasoned wood, good practices, once a year brushing gets barely a cup full for each flue.

Many around here who have "been burning wood for a long time..." burn as follows: throw logs in, damp the air fully down, walk away. They say that their flues need cleaning a few times every year because of safety.
Roof ladders are common, usually nailed wood.

 

[firefighterjake]

So which is better, stove top or pipe thermometer ? I have a basic rutland magnetic stove top unit that is positioned on the corner (as per jotul). I have double wall stove pipe though. Should I try and get a probe type unit and drill a hole ? What is a good flu gas temp ?

I have both a stove top thermometer and a probe-style thermometer for my double wall pipe. While I think both are important, I find myself using the probe thermometer more often to run the stove and insure it is burning cleanly and efficiently.

Good temp for internal probe thermometer on a double wall pipe is 400-900 degrees F . . . but in practice I try to keep the needle between 450 and 550 degrees F since you've got to figure these thermometers aren't always known for being spot on accurate in terms of numbers.

 

[begreen]

No need for extra data....unless it's fun. The stoves are engineered for stove TOP temps for use.
Flue temperatures should be much higher than the stove surface for combustion of exhaust gases.

With a modern stove, if it's burning right, the flue temp is often lower than the stove top. If not, it's wasting heat up the flue. Typically, except on startup, we will see flue temps about 100 to 200 degrees under the stove top temp on the T6. It was similar on the Castine.

I would be concerned if when the stove is burning at 650-700, the flue was sitting at 800-900 degrees for an extended period. It could mean that the baffle was being bypassed and the flame was going directly up the back of the stove to the flue.

 

[oldspark]

Been burning wood for a long time and knowing what the flue temp it for saftey reasons not fun and has been for ever!

Your choice.

But, no real need for flue probes. EPA stoves are engineered for users to monitor temps ON the stove: not overheating, not smouldering low. When we finally got a 'real' tech stove in the later 70's, Vermont Castings had plant and dealer programs for customers to burn right and buy. Going to a seriously engineered stove like the Vigilant and Defiant then was an educated joy. Previous stoves: Ashley, Fisher, Morso 2BO, Lange, Jotul 602, Tempwood. Yes, A true compulsive wood stove freak. :bug:

Safety is burning cleanly, efficiently: get the splits combusting first, then damp the air, no matter whch technology you have--pre-EPA, cat, non-cat. Could take some time for the load to gas off for combustion.
Seasoned wood, good practices, once a year brushing gets barely a cup full for each flue.

Many around here who have "been burning wood for a long time..." burn as follows: throw logs in, damp the air fully down, walk away. They say that their flues need cleaning a few times every year because of safety.
Roof ladders are common, usually nailed wood.

On start up my flue temp are going to be really high if I wait for the stove top to get hot so monitoring the flue temp is a reasonable thing to do, very possible to hit well over 1000 degrees on start up if you do not keep an eye on things, not sure why any one would think there is no need to monitor flue temps. I never turned the air all the way down on my old stove, I do not burn wood that way and never have, I do know how to run a stove and letting the flue temp go through the roof is not a good idea.

 

[oldspark]

No need for extra data....unless it's fun. The stoves are engineered for stove TOP temps for use.
Flue temperatures should be much higher than the stove surface for combustion of exhaust gases.

With a modern stove, if it's burning right, the flue temp is often lower than the stove top. If not, it's wasting heat up the flue. Typically, except on startup, we will see flue temps about 100 to 200 degrees under the stove top temp on the T6. It was similar on the Castine.

I would be concerned if when the stove is burning at 650-700, the flue was sitting at 800-900 degrees for an extended period. It could mean that the baffle was being bypassed and the flame was going directly up the back of the stove to the flue.

I am mainly talking about start up and after a new load has been put in, I assume that you understood that, after the fire has settled in I see the stove top temp higher that the flue but that is not the case on a reload or start up. I am not an idiot although I have played one in the past.