13NC stuck in an overfire mode

SmokeyCity Posted By SmokeyCity, Apr 23, 2011 at 3:35 AM

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  1. SmokeyCity

    SmokeyCity
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    Mar 6, 2011
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    I am burning super dry doug fir beams in the 13NC and it has been getting hotter and hotter so I have shut the air down all the way.
    Even with full stop it is running at over 750 on the deck and about 425 on the stack.

    I just opened the cleanout door on the chim to act as a baro damp to steal the draft from the stove intake.

    This is scary - never happened like this and ironically its is the last night I expect to burn - thats why im burning these chopped up beams instead oif real splits.


    ...wel....l as im about to post this .. i see the temps dropping very slowly - the cleanout door must be stealing enough draft to starve the stove a bit

    now steady at 700
     
  2. wkpoor

    wkpoor
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    It was a regualr occurrance for me on the mag. Heck 750 wouldn't have fazed me since I regularly saw 800+. Does the 13 primary air control set to never fully shut down?
     
  3. Beetle-Kill

    Beetle-Kill
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    Single wall pipe for the stack? Double your reading and you're at 850 °F for the flue, still OK. I hope mine will do that when I have it installed.
     
  4. SmokeyCity

    SmokeyCity
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    the 13NC like most other stoves does not cut the intake to zero when fully closed. There is still plenty of air coming in even at full stop.

    Likewise - when you are trying to start a fire - open akll the way is never enough - you have to crack the door till it gets going
     
  5. SmokeyCity

    SmokeyCity
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    yeah single wall galvanized pipe.

    So the real internal stack temp is twice the surface reading ?

    If 800 is OK - why does the RUTLAND thermo read overfire at 600 ?

    If 800 on the top deck is still OK - then thats good news for me and I wont worry about it.
    I like to burn it hot to kill the creosote
     
  6. GAMMA RAY

    GAMMA RAY
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    I have been seeing those temps...specially when burnin in these milder temps.....stove top at 750 usually happens lately upon loading but slowly starts to go down and cruise at about 550-600. My stack temps are usually 350-425....those temps used to phase me but not anymore...since I have been burning hot, whenever my husband cleans or inspects the flue....nothin in it...cap stays pristene....(I did notice how the cap gets gunky when burnin marginal wood....)
     
  7. leeave96

    leeave96
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    This overfire is a concern of mine for when I install my Englander 30. My plan is to install a flue pipe damper as a safety. It will always be open, I won't ever use it to control a normal fire - only the stove damper, but if there is a runaway or God forbid a fluefire, then I'll close the pipe damper. Better to have it and not need it and the other way around.

    You might install a flue pipe damper, but also cut down on the size of the load in the stove during these shoulder season burns.

    Good luck,
    Bill
     
  8. pen

    pen
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    750 is nothing to worry about. I just certainly wouldn't be loading those old beams onto a hot coal bed or else you could have them take off too fast / hard on you.

    It may seem counter-intuitive but some people actually open the stove door if they are in overfire mode (which you weren't too yet). This stops the very effecient 2ndary burn cycle and allows cool air to rush up over to top of the stove on the inside to cool it as well as up the chimney.

    As leeave mentioned, perhaps you'd benefit from a key damper. I have one on mind and it's been used only 2 or 3 times because of weather, but a few handful of times to control the burn when things rocking and rolling a bit too hard.

    pen
     
  9. blel

    blel
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    My 13 has occaisonally been in the 750 range. What works good to bring it back down is to cover the air intake on the back of the stove with aluminum foil.

    Opening the door actually does work but I don't like having it open with the stove that hot.
     
  10. begreen

    begreen
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    Have to ask, if high temp safety is a concern, why is this connected with galvanized pipe? This is in the TV room right?
     
  11. pen

    pen
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    I missed the galvanized pipe BG, good eye. That is definately not kosher.

    Reason that is where the rutland says overfire is because the rutland is a basturd thermometer: It's scale is a compromise of what is expected for stove top operation and stove pipe.

    Here is an example of seperate stove pipe vs stove top scales:

    stove top
    [​IMG]


    stove pipe
    [​IMG]

    pen
     
  12. begreen

    begreen
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    If the Condar stove top thermometer had an alarm for when the needle hit the red zone, I would be hearing it a few times a day in the winter. 700 on our stove top is pretty common after adding a full, fresh load of wood.
     
  13. wkpoor

    wkpoor
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    To me thats putting a good EPA test result ahead of safety. I like the primary air to be regulated down to zero.
     
  14. fossil

    fossil
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    If this is an accurate statement, then you've got some action to take. Galvanized pipe is not appropriate for a woodstove flue. The temps you describe don't really sound like much of a problem, so far as the stove is concerned, but galvanized pipe is for lower temp applications, not woodstoves. Rick
     
  15. Joey

    Joey
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    Those Doug Fir beams burn wayyyy hot. I just use them to mix in with the good cordwood to get the firebox nice and hot. If ya load up your box with them...your just askin for trouble.
     
  16. begreen

    begreen
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    That's like saying a modern car is less safe than the old ones because it can go faster. If you run the stove correctly and check the flue regularly, overfiring is not much of a worry. I haven't had one in many years and in that case it was my fault for leaving the air control open and then spacing it out.

    There is not a "good amount of air" coming in with the air control closed all the way. There is a "limited" amount of air allowed in to maintain minimum fire. If the user was allowed to choke the fire completely down, about 25% of the old timers would do that every night and choke up their chimneys regularly. And some of them would have chimney fires because of this habit, which is not exactly safe either.
     
  17. SmokeyCity

    SmokeyCity
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    I have a bunch of galvanized around - thats why I used it.

    What is the exact type/brand that would be optimal for my application?

    I wanna do it right when I fire up again in the fall

     
  18. SmokeyCity

    SmokeyCity
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    Mar 6, 2011
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    so all I really need to know is - what is the actual optimal range for the stack?

    and what is the actual optimal range for the deck lid?

    I can still use any thermo that is accurate - and just ignore the range labeling on my crappy RUTs and go by the numbers on your images

    THANKS!!!




     
  19. begreen

    begreen
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    Got a case of the eager beaver eh? That's understandable. But you do want to watch using galvanized indoors. For replacement, 24 ga black pipe is recommended for single wall. The brand might depend on what it ties into. Is the connector tying into a thimble in a chimney or connected to class A pipe?
     
  20. North of 60

    North of 60
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    Not good stuff for your kids to be breathing either. :sick:
     
  21. pen

    pen
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    This recommendation will vary, but here's mine for this stove:

    I'd keep it below 450-500 as measured 18 inches up black stove pipe.

    And I'd aim at keeping the stove top below 750-800 in the hottest spot.

    pen
     
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