Is this normal when you dial the stove down

[lillyrat]

I am working at loading the stove with about a half load, 1 round and 4 splits, and dialing it down to see how it burns so that eventually I can load it full and back it down for an overnight burn. What I found was that I need to back my air all the way off to get the flue temp (magnetic thermometer) to stay below 400.
I loaded the wood on a nice coal bed and with full air and flue temp at 300. I turned air down to half when the flue hit 400 in about 4 minutes. Flue temp continued up to 500 in about 4-5 minutes. Turned air to L which is below 1/4 of the way open. Flue temp slowly came down to 400 but then after a while began to creep back up. Got back up to about 450 on the flue so I shut the air all the way down and the flue dropped to 375 or so and the stovetop was up to about 475 with the fan on.
My main concern was the flue temp was creeping up above 400 with the air about 1/4 open. and still had lots of flames going on. I want the flue temp to come down and stay down. This may have been a function of the EBT opening and letting more air in. The stove is responsive to air adjustment but I am thinking my flue temps are hotter than they should be, outside temp was 39. Stove has 20' of 6 inch liner. Will flue temps remain high on EPA stoves even when the air is down?
Thanks for any input.

 

[begreen]

The flue temps will rise a bit at the beginning of secondary burning, then will settle down for the long haul.

 

[lillyrat]

Should I have to shut the air all the way down? I am trying something different tonight. I am loading the stove and trying to shut the air down alot sooner before things get to wild in there.

 

[oldspark]

When I reduce the air on my summit the flue responds fairly quickly, you must have a stronger draft, it does sound like you can back the air off sooner, I do run my stove with the air down below a 1/4 after the fire has settled in.

 

[Backwoods Savage]

Lillyrat, everyone has to do a little experimenting with their stove and installation. A good example is on our stove, we want to allow the flue temperature to get to 500. Then when we turn the cat on and drop the draft, the flue temperature does drop. But I would not call 400 degrees flue temperature anything to be concerned with.

 

[Chettt]

Sounds like you have a good stove and draft set up. High temperatures are what you want. 500 on your stove face thermometer and 6 to 700 on the flue. The whole thing to remember with wood heat is that if you double your stove temperature, the heat produced isn't doubled, it grows exponentially. It's not cold yet but when winter really hits you want to get those temps up.

 

[oldspark]

Sounds like you have a good stove and draft set up. High temperatures are what you want. 500 on your stove face thermometer and 6 to 700 on the flue. The whole thing to remember with wood heat is that if you double your stove temperature, the heat produced isn't doubled, it grows exponentially. It's not cold yet but when winter really hits you want to get those temps up.

6 to 700 degrees on a magnetic flue thermometer (thats what OP has) is cooking, are you talking about a probe type?

 

[Chettt]

Sorry old spark, I have a single wall flue so my temperatures are probably a bit high. 500 on the stove front though is a good temperature to shoot for and 400 is certainly nothing to fret over if the stove is properly installed.

 

[oldspark]

Sorry old spark, I have a single wall flue so my temperatures are probably a bit high. 500 on the stove front though is a good temperature to shoot for and 400 is certainly nothing to fret over if the stove is properly installed.

I am confused (again) 6 to 700 on a magnetic single wall stove pipe is too hot IMHO, the flue temp should be lower than the stove top except for reload and start up.

 

[Todd]

Sorry old spark, I have a single wall flue so my temperatures are probably a bit high. 500 on the stove front though is a good temperature to shoot for and 400 is certainly nothing to fret over if the stove is properly installed.

I am confused (again) 6 to 700 on a magnetic single wall stove pipe is too hot IMHO, the flue temp should be lower than the stove top except for reload and start up.

I agree, too hot, there might be an overdraft situation and a need for a pipe damper, too much wasted heat up the flue at 600-700.

 

[Funnyfarm]

I have a Summit with 24' of straight up chimney. Lots of draft. Here's what works for me. I get the flue to almost 500 (magnetic on single wall) and start backing the air down, trying to keep it right around 500. Once I get the air all the way down (about 30 minutes), the flue temp will start dropping and always settles at about 350. Stove top climbes to 625-650. I almost always run with the air turned all the way down and I've never had it get too hot on me and the chimney stays super clean.

 

[lillyrat]

Thanks everyone, that was really good information. I just get really nervous with the flue at 500 for too long I have yet to get even the least bit concerned about stove top temps because the highest I have had them was about 575. I found out last night that it also depends on the load of wood, I have read it on here plenty of times but until you experience it, it doesn't make sense. I had some 1 year old oak in there last night with some really dry poplar and hickory and I had to run with more air or I would lose the secondary burn. My wife kept asking me why I was going outside and I had to explain to here that I was checking the chimney for smoke. It was really pretty neat, I had flame in the box but no secondary so I thought I would go out and see if there was smoke and there was. Went in and gave it some more air got secondaries going again, went out and there was no smoke. I was having fun seeing just how much air I could take away and keep secondaries going. I am going to have to stop posting each time I have a burn question like this because each load can be different especially when you change a variable like moisture content of the wood. Thanks for all the input.

 

[lillyrat]

Oldspark, I see your frustration with the mention of 6-700 flue temps. I think that it is obvious to you that 600 flue temps are to high for a magnetic thermometer and I agree with you 100%. I will not let my flue temps get above 550 on purpose no matter what I read on here. I am sure it will happen due to distraction at some point but my main concern is getting a good hot stovetop burn and keeping that flue in the lower half of the burn zone on the thermometer. If I had to choose one thermometer to have it would be without a doubt the flue thermometer for safety reasons. I read the same posts you do and have the same concerns that some people may get wrong information from some posts such as ones that don't convey wether their flue temps are magnetic or probe. I think it is good that you always chime in with regard to making sure people understand the difference, may keep someone with a dirty chimney from lighting the thing up which is another topic. Thanks

 

[oldspark]

Yes I do not mind bumping 550 to 600 on start up and reload and brain fade but I sure do not want to live there as if nothing else it is a waste of heat.

 

[nate379]

Do any of you guys just burn and not worry about temps??

I have been burning wood off and on most of my life and the Blaze King is the first stove I've had that even has a T Stat. I look at it to check that it's in "active" when I engage the CAT and that's it.

 

[oldspark]

Do any of you guys just burn and not worry about temps??

I have been burning wood off and on most of my life and the Blaze King is the first stove I've had that even has a T Stat. I look at it to check that it's in "active" when I engage the CAT and that's it.

Not comfortable doing that, once you see how hot some of this stuff can get it will make a believer out of you, its nice to see the high temps coming and its great for the wife to help her out. I could do it by feel but I like to keep a head of it.

 

[Troutchaser]

We have diff. stoves, but flue temp. is flue temp. and I can tell you that I run 800*+ probe temp and stay there for some time before things start heading south. It's not unusual to peak for a minute or so at 1000*-1100*.

I don't think you're too hot at 500* (750* internal) temp. Our stove shop ran had a Liberty burning at 575* external flue temp. just the other day.

 

[lillyrat]

I agree that 500 is no problem for external temp but like Oldspark said I don't want to live there during an overnite burn. I can't imagine not have the thermometer on there but ya, it definitely makes me a little antsy at times watching the temps hover around overfire on the flue.

 

[astrodon]

.... I loaded the wood on a nice coal bed and with full air and flue temp at 300. .....

In my experience, that is quite a hot flue temp to be reloading. I usually reload when the stove top is 100 to 300. The only time I might reload with the flue at 300 is after a cold startup with a paper bag full of sticks and twigs.

 

[Troutchaser]

I agree that 500 is no problem for external temp but like Oldspark said I don't want to live there during an overnite burn. I can't imagine not have the thermometer on there but ya, it definitely makes me a little antsy at times watching the temps hover around overfire on the flue.

I respect your concerns, but you can't live in that zone for long because your fuel charge is burning down. And hitting 900* isn't the end of the world. You would have to have some serious issues to maintain a flue temp over 900* for any length of time with the bypass and air shut down.
Like I said, touching 1000*-1100* (probe)isn't a big deal for me. It's like a bucket of hot water. Once you get used to it, it aint so hot.
;-)

 

[oldspark]

500 surface is 1000 probe so we are talking about the same thing.

 

[lillyrat]

There is an art to this wood burning though. Just because you take the flue up to 500 and back it down doesn't mean it will stay below 500. I believe with experience you can probably read the fire and have an idea as to how it will burn. I see some people just set it and forget it which I would love to do but I don't know if I will ever get there, may just be my personality, but I would love to be a set it and forget it burner. With that said, I wouldn't actually forget it because I certainly enjoy watching the fire.

 

[Troutchaser]

lillyrat, I understand what you are saying. I am certainly not one who walks away from a fresh burning charge. But once you get the wood charred, close the bypass and minimize the air, the flue should stabilize.

Oldspark, unless I am mistaken, internal flue temp. is 1.5X external. Can anyone help us to clear that up?

 

[oldspark]

lillyrat, I understand what you are saying. I am certainly not one who walks away from a fresh burning charge. But once you get the wood charred, close the bypass and minimize the air, the flue should stabilize.

Oldspark, unless I am mistaken, internal flue temp. is 1.5X external. Can anyone help us to clear that up?

Some members of this forum have tested this and found it to be double.

 

[Troutchaser]

Ya, I've re-read some stuff and seen that.
I was sure thinking we had this discussion last burning season though.