Stove top temp is not always the best start up guide

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begreen

Mooderator
Staff member
Nov 18, 2005
104,423
South Puget Sound, WA
I've said this before, but this morning I got a classic case where watching just the stove top temp is not a good guide for when to start shutting down the air. We had a mild evening yesterday and I was busy. We let the stove die out overnight. This morning was a cold start. I loaded the stove with a couple decent sized fir splits with kindling in between ala tunnel of love style. The fire slowly built up enough so that I could place another big split in the center over the tol and two splits on either side of it. Went in to answer my email. Came back to a serious blaze; the flue was past 1000F and climbing (probe). I shut it down quickly to 1/8 air and that tamed the fire. Stove top was only 275. Lord knows what temp the flue would have been had I waited to 400F as many like to do. Moral of the story: There are times when you need to trust your eyes more than instruments.

epilog: 7 minutes later and the flue is down to 500F with a 475F stove top. I expect when I head out the door that the stove top will be hitting 650F and the flue around 450F.
 
I've said this before, but this morning I got a classic case where watching just the stove top temp is not a good guide for when to start shutting down the air. We had a mild evening yesterday and I was busy. We let the stove die out overnight. This morning was a cold start. I loaded the stove with a couple decent sized fir splits with kindling in between ala tunnel of love style. The fire slowly built up enough so that I could place another big split in the center over the tol and two splits on either side of it. Went in to answer my email. Came back to a serious blaze; the flue was past 1000F and climbing (probe). I shut it down quickly to 1/8 air and that tamed the fire. Stove top was only 275. Lord knows what temp the flue would have been had I waited to 400F as many like to do. There are times when you need to trust your eyes more than instruments.

7 minutes later and the flue is down to 500F with a 475F stove top. I expect when I head out the door that the stove top will be hitting 650F and the flue around 450F.
Indeed, it is an intrique balancing act. There are no hard rules, just a lot of variable rules. Bottom line = play it by ear.
 
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I disagree topoftheriver. There is a hard rule. It is very easy to overfire your flue with a cold stove. If you have no gauge and are not monitoring for this situation then you have failed to properly operate your stove correctly.

Playing it by ear just means you don't know what you're doing. BG has the proper instrumentation, saw the gauge exceed the normal range, and reacted appropriately.
 
If you didnt have the thermometer's, would you have known that you needed to slow down the burn? Of course I believe you would have due to a few years of wood burning under your belt, but if you were a newb,, do you think it would have been obvious?


Glad you caught it!
 
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I disagree topoftheriver. There is a hard rule. It is very easy to overfire your flue with a cold stove. If you have no gauge and are not monitoring for this situation then you have failed to properly operate your stove correctly.

Playing it by ear just means you don't know what you're doing. BG has the proper instrumentation, saw the gauge exceed the normal range, and reacted appropriately.
I have three thermometer. I am not saying not to watch it, you should always exercise caution. When I am building a new fire, of course I keep an eye on it until it reaches operational temperature or other desired temp. The termometers go without saying. Anyone would be foolish not to have at least two, one for the stove and one for the stack. I have two on the stove. I've been burning 45 years with a variety of stoves throughout the years. There is no room for being haphazzard. When I say "play it by ear", I mean keeping and eye on the situation as stated.
 
Did something similar last night, but a hot coal reload after the stove got to about 400 (needed more heat in this cold weather).
Single wall was about 450 external, but stove was only about 500 after just a few minutes.
Killed the air and flue temp came down within just a few minutes, and stove temp went up to about 550 and settled there for a while.
 
When I say "play it by ear", I mean keeping and eye on the situation as stated.

I'm with you now. One thing about safe wood heat is that things must happen in a controllable manner, be predictable, and relatively simple. This is a fire in our homes after all and the operation of the device must be predictable.
 
While reloading my Fireview one time,, which had a STT of 200,,, I witnessed my flue probe temps suddenly jump from 400 to 1000 degrees in what seemed like about 2 minutes...scary if you weren't paying attention for sure... I've learned to respect what can happen if one doesn't pay close attention..I can only imagine getting distracted for a phone call or something.. So stove temps can sure fool you..actually Woodstock told me that a flue probe is a much better way to tell what is actually going on inside your stove,,, makes sense..
 
Yep i go by my probe on start up also i stay with the stove till i get things going and cruising.
 
There is always a lag when lighting a cold stove: I do it every 2 days. By the time you get 5/16th steel on the stove top warmed from the hot air passing underneath it, the flu temps are roaring. Especially with a good draft.

Good point to bring to light for the hardcore thermometer followers.

Andrew
 
Paying it by ear means you know exactly what your doing. There isn't a hard and fast rule for everything when running a wood stove, I think we all know that.

Some people feel warm and fuzzy with 15 different guages measuring temp, weight, how many times they scratched their azz. The rest of us can run a stove just fine without any of that.

I disagree topoftheriver. There is a hard rule. It is very easy to overfire your flue with a cold stove. If you have no gauge and are not monitoring for this situation then you have failed to properly operate your stove correctly.

Playing it by ear just means you don't know what you're doing. BG has the proper instrumentation, saw the gauge exceed the normal range, and reacted appropriately.
 
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Paying it by ear means you know exactly what your doing. There isn't a hard and fast rule for everything when running a wood stove, I think we all know that.

Some people feel warm and fuzzy with 15 different guages measuring temp, weight, how many times they scratched their azz. The rest of us can run a stove just fine without any of that.
I would say I mainly like to know my flu temps so that I'm not on the low side creating creosote,, a hot pipe you can hear starting to make noise along with the roar of the fire box,, a cold pipe you never hear....so it is nice to see some temps in that aspect of burning wood..
 
When I hear the term, "play it by ear" I think somebody is going forward without a plan, winging it. This is not how I run a woodstove. I know what to do when something happens, I have a plan. While not everything about running a woodstove is black and white, the important things regarding safety are known.
 
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If you didnt have the thermometer's, would you have known that you needed to slow down the burn? Of course I believe you would have due to a few years of wood burning under your belt, but if you were a newb,, do you think it would have been obvious?

Glad you caught it!

Ironically playing this one by ear would have helped. Besides the temp, you could hear the metal connector pipe expanding with the heat. But that would have only been a guess. Still, if you only have a stove top thermometer, don't be afraid to turn down the air early even if the stove top has not warmed up fully yet. With a large massive stove that can take a while if coming up from room temp.

The point being is that we get a lot of newcomers here asking "how to" questions. To be really helpful they need to understand that the advice given is general and one should realize that almost every fire is unique. You still have to exercise good judgement about the wood, how it's loaded, draft, outside conditions, etc.. and adjust your plan based on the current fire.
 
I have burned for 40 years. Most of that without thermometers. I have them now on my new stove and the front of my old insert. I find the same thing as most of you, and that is the stove top temp is not always a good indicator. I have always gone by the the fire, and what it is doing. In my old insert, I have never known what the pipe temperature was, but now that I have a probe on my new stove, and know what the temps are on it relative to the fire, I have a good idea of what they are in the pipe on my insert. Really, the thermometers have only reinforced what I always thought was going on before I had them. You know when the fire is too hot and thermometers usually bear that out. The new gear is great and helps tremendously, but don't ignore your instincts.
 
I have burned for 40 years. Most of that without thermometers. I have them now on my new stove and the front of my old insert. I find the same thing as most of you, and that is the stove top temp is not always a good indicator. I have always gone by the the fire, and what it is doing. In my old insert, I have never known what the pipe temperature was, but now that I have a probe on my new stove, and know what the temps are on it relative to the fire, I have a good idea of what they are in the pipe on my insert. Really, the thermometers have only reinforced what I always thought was going on before I had them. You know when the fire is too hot and thermometers usually bear that out. The new gear is great and helps tremendously, but don't ignore your instincts.
I'm with you chief, common sence is the order of the day. If we don't trust ourselves, who do we trust. That said, there is good devices available today to assist all of us in the common goal; keep warm, be safe and keep other utility bills as minimal as possible.
 
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As a young surveyor I learned that you can't always trust yourself and that sometimes, only your instruments can tell you what is right. Ever flown a plane in the dark or fog? Framed a house without a tape measure?

I have three meters on my stove now. Internal flue, stove top, and cat temp. I really don't need stove top and only put it on there for the fun of it to see what is left after 30 hours. After some experience and trust gained, I can say that the only temperature I need to know is the cat temp.
 
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Thanks for sharing BG.

I wonder how many insert owners go through this ritualistically and have no clue otherwise :( (same goes for stove tops w/ a blower going over the thermometer)

I have 4 thermometers I use on my stove (yea, I'm a nerd) and if I could have just one, it would be my favorite flue thermometer.

pen
 
As a young surveyor I learned that you can't always trust yourself and that sometimes, only your instruments can tell you what is right. Ever flown a plane in the dark or fog? Framed a house without a tape measure?

I have three meters on my stove now. Internal flue, stove top, and cat temp. I really don't need stove top and only put it on there for the fun of it to see what is left after 30 hours. After some experience and trust gained, I can say that the only temperature I need to know is the cat temp.
Highbeam, I am confident you are a learned person of your own talent. Many of us on the forum including myself are also. I can't comment on cat temperatures because I have baffles and reburners. All I know is that it works; and darn good. Each one of us has different methods. But it is really about all of us sharing with each other and be as safe as possible. You have to admit, it is fun. Best to you and yours.
 
After some experience and trust gained, I can say that the only temperature I need to know is the cat temp.
Was that experience and trust generated by what actually went on with the fire and the stove as it related to the thermometer reading? It just seems there has to be some interpretation of the temperature and how that correlates with the fire and the heat coming from the stove. I am not arguing with thermometers at all. But it takes the human brain to interpret them.
 
Thanks for sharing BG.

I wonder how many insert owners go through this ritualistically and have no clue otherwise :( (same goes for stove tops w/ a blower going over the thermometer)

I have 4 thermometers I use on my stove (yea, I'm a nerd) and if I could have just one, it would be my favorite flue thermometer.

pen

I think too many new burners rely verbatim on advice we give them rather than adjusting for their local conditions. There's no way we can perceive all the variables that happen in their homes. At times I think we need a Skype connection to view the poster's steps.
 
I use my eyes and senses. Most often the common one.
Have never had a thermometer on a stove.
Nor a moisture meter, not even for the Coo-chi Snorcher
 
Was that experience and trust generated by what actually went on with the fire and the stove as it related to the thermometer reading? It just seems there has to be some interpretation of the temperature and how that correlates with the fire and the heat coming from the stove. I am not arguing with thermometers at all. But it takes the human brain to interpret them.

Yes, time with the stove's window and all meters working. Using my brain to interpret and to verify with the meters. I still have the gauges installed of course but as we settle into routine there is less and less surprise.

As BG says, your experience may differ and if I walked into somebody else's home with the same stove I would be dang happy to have the gauges in place if I had to run the stove for them.
 
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While the air is wide open the heat is flushed up the flue and not heating the stove and stove top as much. But it is heating the flue pipe which is a much less density of the heavy stove so it heats much faster.
 
I think we are all on the same page. BG's first post illustrated the point. Just because the stove is barely warm doesn't mean you can keep firing it hard. The pipe smells hot at 1000::F, whether you have a thermometer to tell you it is hot or not. Use technology, but trust your instincts as well. That is all I am saying. Unfortunately, I have burned some stoves that had no pipe thermometer, or glass. My senses were the only thing to guide me.
 
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