Wood burning 101

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Pascale

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Sep 27, 2012
39
Hello,

I'd like to know how high you run your wood stove ? The guy who installed it said that we could go to 1100F when we start a fire and that the "cruise temperature" could be between 400 and 800F.

Is that enough? Should I run it higher than 800 so the viewing glass stays cleaner?

When should I begin to worry that it's too high?

One last thing: I'm not sure if I should use my thermometer to decide if I should open or close the damper or look at the fire instead: if it looks like it's not burning enough, I open it and vice versa.

My main concern is efficiency since I don't have that much wood (the stove is just an add-on to electric heating)

Thanks and sorry if those questions are really basic!
 
The 1100F he is mentioning is not a stove-top temperature you can measure. What he was referring to is the commonly-quoted temperature required inside the stove for the secondary re-burn to go active. More typical stove-top temperatures are 300F to 600F, although occasional stints up to 800F (or even 900F) is allowable for many stoves.

As measured on top of the stove, I typically run 300F overnight or in warmer weather and up to 600F when I'm trying to heat up the room, although many run hotter. No one is running an 1100F stove-top temperature.

You may want to call that installer and explain your confusion with his explanation, such that he can avoid leaving others (who won't question it) with the same impression. Trying to get your stove top up to 1100F will prove fatal for many stoves.
 
Well, I hate to say it this way, but - What does your stove manual state?

Each stove has it's own specifications.

Also - burn by temperature reading - not by 'sight'. :)
 
I try for a flue temperature in the neighborhood of 400F at 18 inches above the stove top. My flue thermometer is colored coded, which lets me know at a glance if the temperature is in the proper zone.
 
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Welcome.

I think he was telling you what a probe would read in the flue pipe.

Stove top temps range from 400 to 700 or look in your manual.

On a side note i would like add use common sense also cause sometimes stove thermometers can give wrong readings.
 
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Efficiency means getting a full secondary burn of the gases and smoke, which means a hot fire. I would load up at least half of the firebox full of wood (or more, depending how long you want the fire to last) and get the fire going quickly by giving it air either through a cracked open door or leaving the air setting fully open. As the fire engulfs most of the wood, start to turn down the air but allow enough so that good secondary burn keeps going and you aren't belching smoke out the chimney. This will take about half an hour after starting the fire, more or less. you should be able to have almost no visible smoke or vapors coming out the chimney most of the time, which indicates you are burning up everything that can be burned and thus burning efficiently. From that point adjust the air so that a good strong secondary burn keeps going, but there will be some leeway between a roaring blaze and a more controlled burn that still have secondary flames at the top of the firebox. Adjust according to your need for heat in the house. My stovetop thermometer (which i suspect is screwed up) reads around 500 to 750 or so during a normal fire.

Also, get more wood for next year!
 
I can hopefully help by answering this specific to the stove as we have the same stove and as I also after reading through the manuals and not actually finding answers with specific temps stated talked to the tech team at Regency and asked about this. They definitely presented disclaimers that it definitely depends on type of draft, type of fuel, etc. but they did give some great specific answers about temps.

For anyone else reading this post please note that on this stove the "stove top temps" are typically about two hundred degrees less than the temp that one would measure with an IR thermometer pointed to the top of the firebox. This is due to the "free-floating stove-top" design of the CS1200 where the stove-top is cast steel that sits above an air space of ~ .75 inches above the plate steel of the firebox.

So, specific to this stove, with a typical magnetic stove top thermometer I would not regularly run the stove above 600 degrees. This means the firebox is at around 800 degrees plus or minus "x". It is true that the firebox can go to 1000 degrees and then that would mean with a typical magnetic stove top thermometer it would read 800 or so. But that is truly pushing pretty hard and in reality it really would probably push you out of the room too; anything above 600 or so on our stove top thermometer and we automatically put the fan on high to dissipate the heat and then await cooler temps because that basically roasts us out of the area altogether!

The techs at Regency all reassured me that the type of steel, design and construction mean that the firebox can run all day at 800 - 900 but that doesn't then mean the stove top thermometer is reading 800 - 900 or you would be working towards overfire. So I typically run the stove with the stove top thermometer reading at around 400 - 600 degrees depending on conditions outside. By the way, none of this address the "flue temps" where you would have a temperature probe poking into the interior of the flue. Hope this helps.
 
By the way, none of this address the "flue temps" where you would have a temperature probe poking into the interior of the flue. Hope this helps.

Let's go back to the beginning of this thread. :ZZZ

In fact my thermometer is exactly that: a probe that goes through the double insulated flue, 18 inches above the stove.

So what would be the temperatures on that probe that I'm looking for to burn high (to avoid creosote I think? even though my wood is really dry) but not too high that it would be dangerous?

Thanks and sorry for the confusion about the thermometer. By the way, at my cabin, the thermometer is magnetic and is 18 inches above the stove. The flue is also double insulation and the tech told me that it's dangerous to rely on the readings because since the flue is doubled the thermometer doesn't read the "real" temp. Was he right?
 
Let's go back to the beginning of this thread. :ZZZ

In fact my thermometer is exactly that: a probe that goes through the double insulated flue, 18 inches above the stove.

So what would be the temperatures on that probe that I'm looking for to burn high (to avoid creosote I think? even though my wood is really dry) but not too high that it would be dangerous?

Thanks and sorry for the confusion about the thermometer. By the way, at my cabin, the thermometer is magnetic and is 18 inches above the stove. The flue is also double insulation and the tech told me that it's dangerous to rely on the readings because since the flue is doubled the thermometer doesn't read the "real" temp. Was he right?

Yes, he's right.

Magnetic thermometers for single wall flue only, probe type required for double wall, but should be OK on single wall, too. Flue temperatures at 18 inches will be somewhat lower than firebox temperature. 400F@ 18 inches works for me as a target temperature . I would be concerned if it was under 300F or much over 450F @ 18 inches at the height of the burn.

Works for me. I verified my magnetic flue thermometer with an IR heat gun.
 
If double wall pipe, probe type is the only way to get useable readings, would consider a magnetic stove top thermometer also. I run the stove at the lowest setting that I can maintain good secondary burn during off gassing. My stove top temps usual run 400-600 over burn cycle, 500-600 when strong secondary burn is going. I am just installing probe sensor this year, have operated with stove top only with this stove.
Post the type of stove you have and someone here may be able to give an idea of what they are seeing for temps, but user manual should give reference for stove top temps.
 
We normally hit temps of 1400°F inside our stove. The steel and firebrick will glow during most burns.
The stovepipe thermometer reads ~350°F. The living room is usually in the 90's in the winter.
 

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Wow, I don't like the mid-90s in the summer. In the winter those temps would have me suffocated.
 
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We open a window if it gets too warm. Sure is nice when you come in from -30° and feel like an ice cube!

I hear ya on that one. If I came in from -30F I doubt I would be going out again.
 
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. I would be concerned if it was under 300F or much over 450F @ 18 inches at the height of the burn.

Then why does the thermometer has the normal range between 400 and 900F? Under 400 it says too cold and above 900 too hot.

I'm really confused about what I read here.

When the flue temp at 18 inches is 600F, the fire and stove both look perfectly normal and the fire looks well under control. I went to read many threads about the basics of burning (thanks I hadn't noticed them) and read that when the temps are too high it's useless and burn wood too fast. I'm glad I read that, especially since my wood stack is on the small side.
 
Then why does the thermometer has the normal range between 400 and 900F? Under 400 it says too cold and above 900 too hot.

I'm really confused about what I read here.

When the flue temp at 18 inches is 600F, the fire and stove both look perfectly normal and the fire looks well under control. I went to read many threads about the basics of burning (thanks I hadn't noticed them) and read that when the temps are too high it's useless and burn wood too fast. I'm glad I read that, especially since my wood stack is on the small side.

Well, my example numbers came from my single wall flue temps at 18 inches. Your double wall numbers would be higher because of the insulation provided by the dead air space between the walls. Did your thermometer come with instructions that specified a height above the stove top for the installation? If 18 inches is correct for that thermometer, I would go by those numbers.
 
I don't have your exact stove but the 400-900 range should be an ok range. On my probe on double wall pipe I usually see up to 600-800 on start up sometimes and cruse temperature is 450-600 during the main part of the burn and then coasting down. On the flue temps anything above 450 burns clean and I get no smoke out of the chimney and no soot on the glass. My stove top temp tracks pretty much the same to 100* hotter then the flue temp until going into the coaling stage. I would try to keep it no more than 600-700 for normal burning. When you start getting up that high you are sending a ton of wasted heat up the flue and heading toward really short burn times. For example a load running 500-600 on the probe in my stove would be an 8-10 hour burn but 700-800 would burn it up in 4-5 hours. If you are running 500-600 and getting soot on the glass or smoke out of your chimney either your stove has a problem or most likely you are burning wet wood. Running my stove for any length of time between 600-800 will completely clean any haze or soot off my glass and definitely not create any. Anyone responding please keep in mind he is using a probe flue thermometer. I have run both on my setup and the magnetic on single wall truly read nothing in relation to what the probe on double wall reads. If you have a probe type thermometer do not pay any attention to the magnetic single wall numbers. Mine on verified accurate +/- 25* the single wall magnetic would read 300-450 when the same range on my probe would be 400-900.
 
If I ran my Oslo up to 900 stove top measured degrees that would an overfire.

My Oslo is recommended to run in the 400-600 stove top measured range.

Your mileage may vary = means each individual stove's temp range specifications vary.

Repeating what I stated earlier in this thread: Everyone must read their manufacturers recommendations and abide by those recommendations.
 
Repeating what I stated earlier in this thread: Everyone must read their manufacturers recommendations and abide by those recommendations.

Unfortunately, sometimes those manufacturers do a lousy job of communicating their recommendations.

For example, the instructions that came with my Napoleon did not mention what the stove top temperature should be in the operation section of the manual, only the stove pipe, but neglected to say how far up the pipe to place the thermometer. The thermometer itself did not come with any height instructions. Later in the manual, Napoleon talks about loading the stove and mentions optimal burn is when the stove temperature is between 500 - 600 F "beneath the trivet." What trivet? My stove doesn't have one. Measuring the stove temperature with an IR thermometer shows a wide variance across the top, so I have no way to pin point the magic 500 - 600F spot. So my manual, which covers several models, is pretty hopeless. Hopefully, the OP's is a lot better.

One thing my stove's manual does mention that the OP's might not is the fact that it takes several hours of fires to drive all the moisture out of the firebricks. Until that is done, the stove won't perform optimally.

I determined the optimum temperature/height combination for my thermometer by trial and error, watching the burn, observing the top of the flue, and reading lots and lots of threads on this forum. I would have rather had better instructions from the manufacturer, but you do what you have to.
 
I'm really confused about what I read here.

At first glance, it appears to be conflicting information you're receiving, but not really so. The trouble is, you never quoted exactly where the temperature is being measured, and some other folks are not really quoting the specifics of their setup. For example, as WhitePine suggested, he's measuring single-wall flue, and you have double-wall, although I am surprised by such a difference between the two myself.

It's best to concentrate on one factor, eg. stove top temperature. Going back to my original post, I quoted 300 - 600F for my cast iron stove, and stated the occasional foray higher is not of huge concern. The soapstone guys may think running higher than 600F is insanity, and the steel stove guys likely see their stove peak out above 600F on every new load.

Likewise, the 1100F - 1300F numbers quoted are internal temperatures, not typically what you're watching when burning a stove.

Flue temps are a whole other matter, and add another layer of confusion. It may be best to focus solely on stove-top temp's first.
 
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