I have been "flying without a parachute" so to speak for the last three years of burning. In other words, I have not had a flue thermometer installed. I always monitored the temp with an infrared thermometer checking the pipe. The stove pipe is double wall, so I understand this reading does not mean a lot. Anyway, I installed a Condar probe flue thermometer. It shows 400-900 being ideal burn temps. Upon firing my stove up this last week, I am noticing that the "normal" fires I have been building for the last several years are producing flue temps in the 1100 degree range. Have I just been fortunate to not have a problem or is the thermometer marked excessively cautious. My stove manufacturer does not specify a temp. I've never had excessive creasote, though I suppose at high temps I wouldn't. I disassembled the stove pipe entirely for a visual inspection which did not show any signs of damage. I've used this stove to heat my entire house for the last three years. However, if I am in fact overfiring, I may not be able to produce the necessary btu's to heat the house. What do you all run your stoves at?
Flue temp- how high is really too high
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Gunner
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I would think the stove would show signs of degridation before the pipe if infact you have been "overfiring" for the last 3 yrs.
What are the stovetop temps when the probe in the doublewall is 1100.
When I'm charring a new load it is common for the probe thermo in the doublewall to reach 1000 deg. This however does not last more than a few minutes... it falls when I lower the air to the desired setting and usually cuises at 400-600 for the duration of the fire.
What are the stovetop temps when the probe in the doublewall is 1100.
When I'm charring a new load it is common for the probe thermo in the doublewall to reach 1000 deg. This however does not last more than a few minutes... it falls when I lower the air to the desired setting and usually cuises at 400-600 for the duration of the fire.
The probe is mounted about 20 inches above the stove and 2 inches below a 45 degree elbow. Could this affect the reading?
That seems way high temp for 20" from the stove. It's getting into the 'deep red glowing' range and I would think you need to have flame 'licking' the probe to get that hot.
Is this probe a thermocouple ? If so are there any set-up options - like 'type K' or 'type J' thermocouple? Does it read OK at room temp - or does it even go that low? My first thought would be something wrong with the probe to have a reading like that.
Corey
Is this probe a thermocouple ? If so are there any set-up options - like 'type K' or 'type J' thermocouple? Does it read OK at room temp - or does it even go that low? My first thought would be something wrong with the probe to have a reading like that.
Corey
Bjorn, I aim for no more than 900 on startup or a fresh load. Then let it coast back down to the 350-600 range for long term fires. 1100 does seem a little high. Does this temp maintain itself at 1100 through most of the fire or does it also settle down after you get it going?
Most newer stoves are designed so that once the secondary burn is kickin', the primary air is to be lowered so that you "don't" get that kind of stack temp. It prolongs burn times, as well as gives the stove a chance to burn up all the particulate matter that would go up the pipe. Also, if your stack temp STAYS at 1100, consider how much of your wood heat is going up the stack instead of heating your home. Is this an EPA stove? It may just be how it is being operated, and not getting your full "bang for your buck" on the reburn technology.
Most newer stoves are designed so that once the secondary burn is kickin', the primary air is to be lowered so that you "don't" get that kind of stack temp. It prolongs burn times, as well as gives the stove a chance to burn up all the particulate matter that would go up the pipe. Also, if your stack temp STAYS at 1100, consider how much of your wood heat is going up the stack instead of heating your home. Is this an EPA stove? It may just be how it is being operated, and not getting your full "bang for your buck" on the reburn technology.
It's possible it is operator error. When the thermometer reads below 900 degrees , there is not much of a fire going. It does not seem to matter whether I just started the fire or it's been burning for awhile. It climbs to around 1100 and stays there unless I dampen the stove back. It's a Century FW30009 I believe. I realize this is a cheap stove, but it is supposed to be EPA certified. I did kill the first baffle in three years. CFM denied the warranty claim due to "overfiring". This is my first stove, so I have nothing to compare to. Seems to me that a stove should be able to contain a healthy fire safely. I'm burning air dried wood... mostly cherry and oak. The thermometer is a magnetic mount probe brand new from Condar and does not have any means of adjustment. It starts at 100 degrees, so I don't know how accurate it is at lower temps. I guess I could crank my oven and see how accurate it is in there. But I don't know how real the reading would be heating the entire unit instead of just the probe. Perhaps I need to relearn how to burn in this stove. It just seems like at 900 there isn't much fire in there.
tradergordo
Minister of Fire
bjorn773 said:
Possibilities:
1) defective thermometer (try another one?)
2) Air leak in your stove.
a) Check ALL door gaskets, every couple inches, by closing each door on a dollar bill and pulling - if the bill slips out easily, you need to replace your gasket.
b) There is a bigger problem - a leak that isn't a simple door gasket. Get it checked out by your stove shop or a representative that your manufacturer recommends in your area.
1100 internal flue temp is not that unusual, short periods at those temps are unlikely to damage the stove or flue, but it IS unusual to SUSTAIN that temp or higher for long periods (more than 1/2 hour). I would expect you are getting short burn times if your thermometer is working.
jqgs214
Minister of Fire
So you have been burning this stove wide open all the timew and never dampening back?? If thats the case then you DID overfire and continue to do so. I googled that stove model and came up with nothing. Is it a catalyic stove? When you say air dried you mean cord wood correct? not dried lumber? Give us some more info and well get you using the stove properly.
Gordo, checking for leaks is a good idea, but I doubt if that is the cause. Reason being - if he turns down the primary, his flame decreases with it. My guess is that he is looking for a firebox full of big flame, so he adjusts the air to obtain that. If that is the case, it could easily get to an overfire condition. What kind of stove top temps are you reaching with this thing? Just guessing, you are hitting way over 800 deg. That ain't good.
bjorn773 said:
For the moment, let's assume the Condor is reading correctly. What's important is not amount of flame, but the heat that the stove is producing. You need to get a stove top thermometer, preferably today.
At this point you need more data, but I am guessing that you have been overfiring the stove. Once you have the stove top thermometer, place it on the top, about midway between front and back. The goal should be a stove top temp around 650 degrees, but if the temp is rising rapidly, you might want to start throttling back the air around 600. Let us know what you are getting.
tradergordo
Minister of Fire
Jags said:
Yea, I was thinking in terms of newer stoves where it is virtually impossible to overfire due to air control settings alone (you can pretty much only overfire from a leak, from deliberately opening a door, or from burning excessively dry wood). I guess the air control factor might be the most likely culprit on an older stove though?
tradergordo said:
Caution....I think even EPA stoves can be overfired (at least my quad will) if the primary air is not controlled properly. I use typical 15-20% cord wood and I could easily hit WAY over 800 without trying too hard. The stove and stack are tight as a drum, so it comes down to human control.
Highbeam
Minister of Fire
Yeppers, easy to overfire an EPA stove. No good way to slow them down without control of the secondary air either.
It sounds like you continued overfiring that stove. Noway should you be reading a constant 1100 in the stack 20" above that stove
you must have to feed that stove constantly to maintain that stack temps Couple of suggestions here one A stove does not have to be overfired to produce heat I think you are trying to create instant heat. there is another objective try burning 24/7 at a constant output in a moderate range that stack should not be reading over 700 degrees you should be dampering down and the flames will subside into a controlled longer safe burn. That is a welded plate steel stove so the only gaskets are on the door and glass, possibly the ash door.
If you continue running the stove in the same manner you are testing the limits of safety. I am willing to bet you have seem a glowing red on the stove and stack pipe.
It is also possible that stove is too small for your area. I glad you posted here before a disaster occurred. Think in terms of 24/7 and not fa
Ok, I need to provide a bit more info here. I do burn 24/7, but not at these temps. I have only just started burning in the last couple days so all habits stated are from the last three seasons. I will start a strong fire(wide open damper) in the evening and typically keep it burning that way for a couple hours, then dampen down all the way. A load of wood in the stove will typically last 4 hours when the damper is at its lowest setting. In milder weather I will start another fire in the morning which burns wide open for about an hour. Then I dampen down and burn until the fire goes out. In very cold weather I will reload the firebox in the middle of the night and burn it dampened down once it gets going. I am burning air dried cord wood mostly oak and cherry. I do not have a stove top thermometer, but will get one asap. In the meantime, I will measure with an infrared thermometer. I believe the stove to be free of any air leaks. It has two air intakes in back that feed air tubes at the top of the firebox. The damper controls air fed across the glass door. The only seals are around the glass(clear ceramic of some sort) and the door that contains the glass. They are in good condition. If it is being overfired, it is due to my fault alone. Never having a thermometer before, I always looked for a "firebox full of flame" as Jags stated. Yes, when wide open I do burn quickly. So I have been overfiring for 2-3 hours a day on average. I will report stovetop temps once I get the stove at a steady cruise tonight and take a measurement.
Try this modification of procedure. Start burning as usual, but damper down to 50% after 30 minutes of good fire. (Or stovetop temp of 450-500). Watch the temp over then next hour or two. If it climbs over 650, damper down to 25%. If that still doesn't help regulate the temp, damper down all the way. Let us know how that works.
The ideal flame after the first (~50%) dampering down will be a rolling blue-orange flame at the top of the firebox, under the secondary air manifold - not an orange/yellow blaze on the wood itself. Without knowing the stove and setup, the 50% recommended setting is an approximation. It may be more like 60% or 25 %. You'll have to judge that. For a video of how it looks in my stove here is a link:
http://www.youtube.com/watch?v=lR98Z4zvX8k
The ideal flame after the first (~50%) dampering down will be a rolling blue-orange flame at the top of the firebox, under the secondary air manifold - not an orange/yellow blaze on the wood itself. Without knowing the stove and setup, the 50% recommended setting is an approximation. It may be more like 60% or 25 %. You'll have to judge that. For a video of how it looks in my stove here is a link:
http://www.youtube.com/watch?v=lR98Z4zvX8k
I fired up the stove about an hour ago. When the fire got going the temp climbed to about 850 degree flue temp at which time the hottest reading with my infrared on the stove top was about 750. These readings are with the stove running wide open. The temp then started to slowly drop. The wood I am burning was just brought in from my wood pile tonight (pile covered on the top with a tarp, stacked next to a garage wall). The wood I burned the other day when the temp was so high had been sitting in my basement since last year. Perhaps my previous data is a bit off since that wood was so dry. Regardless, I will get a stove thermometer and report my findings. Thank you all for your input.
Yes, you'll need to govern the stove by the quality and size of the wood. A stovetop thermometer will help a lot here. Try to keep the stove top under 700. An occasional spike at 750 is ok, but running daily at 900+ is not.
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