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Confused about flue heat temperature

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by DamienBricka, Nov 12, 2013.

  1. DamienBricka

    DamienBricka Feeling the Heat

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    I have a CFM FW240007 stove. I bought the other day a magnetic thermometer at Lowes to make sure I was burning wood efficiently. I cannot get the reading about 300 degree F. On the other hand my glass on the stove is clear. I have to increase the temperature with no much success. Today it is 0 F out side 70 F inside, Outside flue temperature is around 180 F. The air intake on the stove is completely closed. Am I running the stove right or am I way off. Thanks for the input, Damien

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  2. Excavator

    Excavator Burning Hunk

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    You might be reading celsius by mistake 300c = 572 f 180c = 356f
  3. DamienBricka

    DamienBricka Feeling the Heat

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    I just check again to make sure and the temperature is in F
  4. bag of hammers

    bag of hammers Minister of Fire

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    A magnetic temp gauge - sitting on a single or double wall stove pipe? the actual flue temps may be much higher than the gauge reads, if it's a double wall.
  5. Backwoods Savage

    Backwoods Savage Minister of Fire

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    When you are talking about flue temperatures, we need to know how you are taking the temperatures. Single wall, double wall, how far from stove, etc.? Also, closing the air intake completely is usually not the best. Better to give it some air. Not necessarily a lot but some.
  6. DamienBricka

    DamienBricka Feeling the Heat

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    sitting on a single wall stove pipe. Around 200 F now. I read you have to multiple the temperature by 2. Is that about right?
  7. altmartion

    altmartion Feeling the Heat

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    I wouldn't think so. you may want to get another gauge. it should read actual temp.
  8. Backwoods Savage

    Backwoods Savage Minister of Fire

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    I would think that is a pretty low reading for flue temperature.
  9. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    Interior pipe temp is around twice the surface measured temp.
  10. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    Put the mag thermometer down on the stove top just in front of the step down and see what the stove temp is reading.
  11. fossil

    fossil Accidental Moderator Staff Member

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    I have that stove in my shop. Single-wall stovepipe. Magnetic thermo stuck just above the flue collar. Routinely cruises around 400°F. Early in a burn it can approach 600°F. I don't sweat what the actual flue gas temp might be, or the temp inside the firebox, or on the stovetop. I don't care. I use the mag thermo on my stovepipe as my operating guide. I've learned what's normal.

    shopstove.jpg
    Last edited: Nov 12, 2013
  12. altmartion

    altmartion Feeling the Heat

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    so you are saying that my flue is actually 900 degrees when the temp gauge reads 450 degrees. I figured it would be glowing before that. I guess I better pay attention.
  13. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    It glows at around 1,400 surface temp. Don't ask how I know. ;em

    A probe pipe thermometer that sticks into the pipe interior is the only way to read actual flue gas temp. 1,000 degree flue temps on startup of fresh loads isn't all that unusual.
  14. DamienBricka

    DamienBricka Feeling the Heat

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    Ok BrotherBart. Then what is a good probe pipe thermometer for a single wall pipe stove
  15. fossil

    fossil Accidental Moderator Staff Member

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    You don't need a probe thermometer, just a surface mount with reasonable accuracy that you come to "know" through experience with it. You're just operating a wood stove, not conducting a physics experiment.
    dyerkutn likes this.
  16. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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  17. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    fossil is correct. My stove has never had a pipe thermo on it. In 30 years.

    Edit to add: Pipe thermos were great back when you couldn't see what was going on in the firebox. That big hunk of glass in the door takes care of that.
  18. DamienBricka

    DamienBricka Feeling the Heat

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    Temperature on top of stove is 450F
  19. BrotherBart

    BrotherBart Hearth.com LLC Mid-Atlantic Division Staff Member

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    450 and above is doing just fine. That clean glass and not a bunch of crud on the bricks in the morning tells you that you are burning alright.
  20. DamienBricka

    DamienBricka Feeling the Heat

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    Then I am doing alright I will just keep the magnetic thermometer as a reference but will not rely on it yo much. I guess for a newbie I am doing a good job. I want to thank all of you for your wisdom it is helping me build my confidence in wood burning. Thank you
  21. fossil

    fossil Accidental Moderator Staff Member

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    That's what we're here for, my friend. Rick

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