# How hot is your woostove/stovepipe??



## Beeman (Dec 29, 2002)

A post a while back about wrapping a stovepipe with copper tubing to heat water got me thinking. I have a Raytek non contact infrared thermometer and my stove is burning. it's in the 30's outside and in the 80's in here so I've got it's air cut back. 
stove top griddle is 350*
stove sides are 275-300*
stove back is 200*
single wall stove pipe goes from 200 to 150* in the first 2'
150-130* in the next 2' and from 130 to 120* in the last section.


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## big rockpile (Feb 24, 2003)

How hot is my Stove Pipe? Like my DM always said,"Don't touch it,it will burn you".  

big rockpile


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## TNHermit (Jul 14, 2005)

I run mine at about 300-400 on my two stoves. That is what they say is best operating temp and produces least amount of creosote. The thermometers are about 3' up the pipe as it comes out the stove. I don't know what the walls of the stove are as it is wrapped in steel and has a blower on it.. The earth stove runs a about what yours is.


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## WolfWalksSoftly (Aug 13, 2004)

I have one of those magnet stove thermometers, but not sure where to put it for an accurate reading. Should it be on the pipe or on the top of the stove?. I just have single wall pipe.


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## ET1 SS (Oct 22, 2005)

Beeman -

If your stove's hottest is 350*, and by the time that the gases get up to the 
highest sections of stove pipe th etemps are down to 130 to 120* it soudns to me like most of the heat has been radiated into the room.

Well done.


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## TNHermit (Jul 14, 2005)

WolfWalksSoftly said:


> I have one of those magnet stove thermometers, but not sure where to put it for an accurate reading. Should it be on the pipe or on the top of the stove?. I just have single wall pipe.


THey recommend 5ft from the stove if you can do it. Mine is only about 3 cause it goes in to the chimney. Watch you don't put it on a seam  it will hang up and give a false reading. DAMHIKT


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## Ross (May 9, 2002)

You do want a high enough temp to properly vent the smoke. Anything under 300 is going to need a pretty short chimney or you'll get creasote and condensation/chimney damage and or downdrafting.


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## Quint (Nov 12, 2004)

Hotter than the surface of the sun. I have to surround mine with a magnetic field in order to contain the heat and pressure. If I inject Lithium 6-Deuteride into the magnetic field I can actually initiate a thermonuclear reaction.


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## Cabin Fever (May 10, 2002)

Theoretically, you want the inside of your stovepipe, and all the way up into your chimney, to be above the temperature of boiling water (212ÂºF). If the temp drops below 212Âº, steam will condense on the inside of the stovepipe or chimney pipe. This moisture is what starts creosote to form. The LAST thing you want to do is extract heat from your stovepipe and have a cool chimney! 

The best place to measure flue gas temps is at the very top of the chimney (which unrealistic). The gases leaving the chimney should be above 212ÂºF. Since this is not possible to measure, the temp of your stovepipe should always be 300ÂºF or above. At this temp, most woodburning set-ups should have sufficient heat in the stovepipe/chimney to keep moisture from condensing.


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## Ross (May 9, 2002)

That's a good way to explain why you need a higher temp to vent the smoke! I have tables for oil burners that size chimney diameter and height and the required temperature to properly vent. The higher or bigger the chimney the higher the temp you need. If it's over 25 feet tall get that temp over 400 degrees F


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## Beeman (Dec 29, 2002)

Cabin Fever said:


> Theoretically, you want the inside of your stovepipe, and all the way up into your chimney, to be above the temperature of boiling water (212ÂºF). If the temp drops below 212Âº, steam will condense on the inside of the stovepipe or chimney pipe. This moisture is what starts creosote to form. The LAST thing you want to do is extract heat from your stovepipe and have a cool chimney!
> 
> The best place to measure flue gas temps is at the very top of the chimney (which unrealistic). The gases leaving the chimney should be above 212ÂºF. Since this is not possible to measure, the temp of your stovepipe should always be 300ÂºF or above. At this temp, most woodburning set-ups should have sufficient heat in the stovepipe/chimney to keep moisture from condensing.


 Interesting and it makes sense. I can possibly measure the temp exiting the chimney with a digital multimeter and a temp probe. For the stove pipe to get that hot I don't know if I could stand being in the house! I do notice liquid looking creosote that seems to condense when it hits the chimney cap and drips off of it. The wood I'm burning is very seasoned mixed hardwoods.
It's 30* outside now and 77* in here. On catalytic burn, the original was without the stove flipped to catalyst, The stove top is 500* the pipe is 330* and drops to 230* in the first 2',down to 190* in the next 2' and 160* at the chimney.


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## Ross (May 9, 2002)

I am talking base chimney temp, where stove pipe changes to chimney, but that is measured in mid stream of the flue gas not pipe surface temp. There will be a big difference between surface temp and flue gas temp.


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## WisJim (Jan 14, 2004)

I have both a Chimguard magnetic thermometer on the surface of the stove pipe, and a probe type that senses temp about 4 inches inside the pipe. They are both within the last foot before the chimney, and I try to get the temp up to 300 to 400 degrees at least after adding wood, for a half hour or so, to help prevent creosote build up. So far it has worked well--since around 1980. Had a problem with creosote build up one year in the late 1970s or so, due to low temps and not quite dry enough wood, but using a thermometer to monitor stovepipe temps has helped a lot since then. I show little difference between the 2 thermometers that I am using, probably because neither one is calibrated down to the degree, just 10 degrees or so. Oh, I am talking degrees Fahrenheit, too.


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## ET1 SS (Oct 22, 2005)

Cabin Fever- you bring up a good point.

So really then an ideal temperature for our upper chimney is 220F.


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## MelissaW (Jun 18, 2003)

The thermometer on the outside of my wood furnace front usually reads around 400 degrees, and the one on the pipe is usually around 350 degrees. That is the "green zone" recommended on the gauge. My husband always says we'll get creosote if it runs too cool.


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## canadiangirl (Jul 25, 2004)

We had one of the magnetic types but had the probe kind installed this year by our cleaner/inspector. He said they were much more accurate to use than measuring the surface temp of the pipe. Using this probe type, we were to told to burn in the range 400 - 800 degrees and it's marked. It's Farenheit.


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## NYSaanen (Jul 20, 2006)

Ours is an older stove (20 or so years) and we installed an aftermarket catalyst when we got it. The catalyst is mounted on the stovepipe immediately upon exiting the stove. The magnetic probe thermometer is mounted only four or so inches above that, (per manufacturers instructions)with a damper about a foot above that. 

The thermometer is marked off with the following values:
100-600*F Soot and Creosote
600-1000*F Catalyst Active
1000-1500*F Self Cleaning
1500+ Overheat

We have not used the catalyst in a long time...not sure why, don't even know if it would work still. However, When I start up the stove, or reload it, the temp rises to about 1200* and slowly drops from there. When it drops to about 400*, I know its time to reload.


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## homebirtha (Feb 19, 2004)

The magnetic ones won't work on some stove pipes. 

We have a double-wall pipe, so the temperature won't be accurate. Make sure your pipe is only single-wall if you're counting on the magnetic thermometers.


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## ET1 SS (Oct 22, 2005)

I guess that I am fortunate then as we do not have any double-walled stove pipe.


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## greg273 (Aug 5, 2003)

I try to let the chimney temp 3 ft above the stove get up to about 900-1000 before I close the main ash door and the damper. And let it ride there for about 15 minutes, in an attempt to clean out the chimney somewhat. As far as 'normal burn', I would say 350-400 is a pretty good range... yeah, you might get some creosote in the upper reaches of your chimney, but thats what the initial 'hot fire' is for...


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## highlands (Jul 18, 2004)

Base of the pipe at the wood stove is hot as balled spit. (Spit there and it balls up and bounces). Probably about 400 degrees.

22 feet away at the exit of the house it is warm to the touch with a bare hand.

No creosote build up or moisture condensation inside the pipe because it is a complete burn. Good wood, proper oxygen, long path and turbulance are all important.

Cheers

-Walter
Sugar Mountain Farm
in the mountains of Vermont
http://SugarMtnFarm.com/blog/
http://HollyGraphicArt.com/
http://NoNAIS.org


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## Cabin Fever (May 10, 2002)

highlands said:


> No creosote build up or moisture condensation inside the pipe because it is a complete burn. Good wood, proper oxygen, long path and turbulance are all important.....


FYI. The process of combustion produces moisture. In other words, your firewood could be completely dry (0% moisture) and there would still be moisture in your flue gases that could potentially condense and promote creosote formation.


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## Sparticle (Nov 1, 2004)

Quint said:


> Hotter than the surface of the sun. I have to surround mine with a magnetic field in order to contain the heat and pressure. If I inject Lithium 6-Deuteride into the magnetic field I can actually initiate a thermonuclear reaction.


 :bow:

Ours runs right around 300. Hotter than that and it's too hot in here.


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## highlands (Jul 18, 2004)

Cabin Fever said:


> FYI. The process of combustion produces moisture. In other words, your firewood could be completely dry (0% moisture) and there would still be moisture in your flue gases that could potentially condense and promote creosote formation.


FYI. The inside of the pipe is completely dry and has no creosote. Reality.


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## raymilosh (Jan 12, 2005)

Let's see. My magnetic temg gage says about 200 degrees F. 
I know it leads to creosote formation. I sweep the chimney as necessary and collect the creosote. It is good for preserving wood (creosote posts are made by dissolving creosote and painting it on wood. It is naturally poisonous, so anytthing that tries to eat the wood dies. It is also a good insecticide. 
Stealing heat from the chimney will lead to creosote formation and will lead to the creation of hot water. Everything is a tradeoff, I spoze. 

Another possibility...I did this in a neighbor's house and it is working fine. I made a water jacket out of 3/4 inch black steel pipe shaped like this:
______________________
______________________|
|_____________________

and installed it in the firebox and drilled holes out the back and hooked it to copper pipes leading up to a water heater tank. I followed all the ideas and cautions from the Lehman's book "Hot Water from Your Woodstove."

That solves the creosote problem and gets the water closer to the fire. The system I built will make 40 gallons of scalding hot water within a few hours of a hot fire and employs no moving parts and has never overheated it to the point the pressure relief valve opened even thoough the woodstove is used for heating the whole house.
If interested to see more, PM me and I'll take some pictures and send them to you.
Ray


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## Cabin Fever (May 10, 2002)

highlands said:


> FYI. The inside of the pipe is completely dry and has no creosote. Reality.


Good for you!

I hope the rest of you keep sweeping your chimneys on a periodic basis especially if you practice damped down burns at night, burn less than seasoned wood, and/or where much of your chimney is out of doors.


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## ET1 SS (Oct 22, 2005)

Last year I dis-assembled our stove-pipe, and cleaned it.

Being a straight vertical run of only four lengths of pipe, it was very easy to do.

It is my intention to continue doing this once each summer, for as long as we use this stove.

We burn just about anything and everything in our stove. And I was pleasantly surprized to find very little build up of any creosote or ash. Most of it was in our upper chamber, I think that some may have formed in the stove-pipe and then fell down into the upper chamber. 

In either case, it was fairly simple to do. and much less of a mess than I had expected.


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## Ross (May 9, 2002)

Cabin is bang on combustion produces water vapour, if you haven't got condensation in a cool chimney then great, you probably have good currential drafting. Lucky you.


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## highlands (Jul 18, 2004)

Ross said:


> Cabin is bang on combustion produces water vapour, if you haven't got condensation in a cool chimney then great, you probably have good currential drafting. Lucky you.


It isn't luck. It's physics. Aim for it. I'm not being facetious. I'm serious. Design it to work. There are reasons why stoves work or don't work. Study them. Understand what makes it work. What makes it fail.

Chance favors the prepared mind. -Louis Pasteur


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