I've read here and elsewhere that most folks stoves flue temps run about 100-150*F cooler than the stove top temperatures once cruising. My 13NC seems to always have the flue temps slightly higher or just equal to the stove top temps. I have 2 stove top thermometers (from different manufacturers), and they are usually pretty close in their readings. I also have a SBI probe thermometer just above the back-to-back 45's which come right out of my stove. Before I get the stove damped down, I can and do see flue temps pushing 1000*F.............while my wood is barely charred yet and stove top temps of 350-400*F. I find myself damping down the stove by the looks of the fire rather than by what the thermometers say. The only cause that I can see is the "shallowness" of the 13's firebox. I can usually only get 2 rows of wood loaded EW and just 2 layers high into her unless the splits are very small. As the wood is charring, the fire gets vigorous, and fills the box............I damp down to 50%..................flames ease a bit, but the flue temps climb faster than the stove top temps. As the flames fill the box again; I damp down another 50% (75% closed now).....................now the flue temps will be near 1000*F and the stove top temp around 500-550*F. From here; the flue temps will settle and come down, but never get BELOW the stove top temps even with the air damped all the way down. The SHALLOWNESS of the firebox is the culprit IMHO........................the flame don't have far to travel in the box to get around the baffle board and then basically up the flue. My 2 stove top thermometers divide the front of the stove top into 1/3rd's, and unless I have more fire on one side of the box vs. the other............they're close. One responds faster than the other, but once cruising they're close to the same. There are no door gasket leaks or door glass gasket leaks. My OAK pulls air from the crawl space. Other than this potential ANOMALY, I've nothing but praise for this little stove. That's why I in the "OTHER THREAD", I call her "Little Big Stove". What y'all think???? Am I picking really small nits??? This is on edit......................I forgot to add this...............I'm burning mainly silver maple and box elder now. And this is a picture my furnace thermostat (furnace not on yet) on 2 medium loads of said wood today. I guess what I'm asking is............................Am I losing more heat up my chimney than I should be???
It sounds to me like your doing fine, in the ballpark of "normal". I'm running a nc30, single wall pipe, 2 feet straight up, then a 90 then 2 feet into a masonry chimney. I run a damper at 18" above the stove. I have a probe temp just below the damper. I measure STT with an IR thermometer. I see the same thing you do with substantially higher flue temps until the stove catches up. When damped down and cruising during active burn my flue temp is consistently 50-75 higher than STT. During coaling the flue is still always higher than STT but the differential is not as great.
Whitey, what I'm seeing is that you are reading the stove top temperature but on the flue you are reading the interior temperature. A huge difference! If you read that stove top temperature to mean 700-800 then it is a lot closer. In addition, it appears you are talking about lighting a fire from a cold stove. Most definitely the flue will and should warm up faster than the stove. You need the heat in the flue to give the stove good draft. No doubt as you decrease the draft and the stove warms, then you should find the stovetop higher than the flue....if measured on the surface; not the interior. Even with our stove, yes, the flue temperature runs much below the stove top. Yet, when starting a cold stove or even on reloads, at first the flue temperature will be higher than the stove top. We also drop the draft to 50% or lower long before the stove top gets very high. Those who don't do this are wasting a lot of heat up the chimney. We watch the flue temperature on both cold starts and reloads and when the surface temperature on the flue reaches 350-400, we cut the draft. This allows the heat to stay more in the firebox rather than shooting up the chimney. As the stovetop reaches 225-250 (on reloads) then we usually take the draft up to about 400-450 and when that is reached, we engage the cat and dial the draft way down. It works.
BWS This essentially happens the same on reloads on an average coal bed; and on my "cold reload" once the wood catches. I do the rake the coals forward routine, put my biggest split in the back...............................and then depending on how much heat I need it's either a split in front of the above split on top of the coals, and 1 above both...............to form a "triangle" of wood with 3 splits............................................or to stack one on the first split and then one on top the the split I put directly on the coals................................in essence a "square" of splits. When cruising................my stove top temps..................actually almost mirror the flue temps. Stove...................Englander 13NC Stove Pipe................5' Double Wall, from Menards.............back to back 45's off stove to clear attic truss Chimney.................11' of Class A, from Menards Wood "NOW"...................Box Elder and Silver Maple The stove doesn't go nuclear at all.........................in fact, it's quite controllable. I'm just axing about the "higher than normal" flue temps..................relltively speaking!!!!
With the fisher i just installed this fall im runnin internal flue temps (18" above the stove) averaging around 650-700°. With a stove top around 450-500°.
MightyWhitey our temps are nearly identical. But, when I put all oak in, the flue stays around 1000 (probe) straight up and out, and the stove top temps are 650 to 700. At what temp on the probe do you begin shutting things down? (I would visually turn things down, but am now trying to pay more attn to actual temps since the stoves secondaries go nuts, fully closed with a load of 3 yr oak) I also run an outside air kit and have blocked off 3/4 of the incoming air outside the house. The colder the temps the more draft, and poss higher flue temps.
