# Measuring Flue Temperature



## ct01r (Nov 26, 2018)

I've seen references about flue temp's, but don't understand the importance.  Is it for efficiency? safety?  I have an infra red reader, and have been "playing" with it, but mostly use it for stove temps to measure different kind of wood.  Any info would be appreciated.  Thanks!

P.S. I tried to do a word search, but couldn't figure it out.  Do you'se have a word search option?  Thanks again!  Curt


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## begreen (Nov 27, 2018)

Knowing flue temp helps. It lets you know if too much or too little heat is heading up the chimney. Too much heat is a waste and too little can mean creosote will condense and build up.


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## ct01r (Nov 27, 2018)

Thanks!  Curt


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## SeanBB (Nov 27, 2018)

I have a magnetic flue thermometer that is 18 inches above the stove outlet. The ideal temperature is between 280 and 500 degrees Fahrenheit.


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## begreen (Nov 27, 2018)

SeanBB said:


> I have a magnetic flue thermometer that is 18 inches above the stove outlet.


Note that this is on single-wall stove pipe. If the stove pipe is double-wall then a probe style thermometer is needed. The probe thermometer will read 1.5x to 2x higher than the surface temp on single wall stove pipe because the probe is directly in the flue gas stream inside the stove pipe. 350-600ºF is a common temp for a probe.


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## ct01r (Nov 27, 2018)

Thanks guys!  I have single wall stainless.  It's been reading under 150 to 200 when I have the damper and air intake closed down (still has enough air leakage going in to keep the stove itself around 300-400 degrees).  When I open it up, the stove pipe reads in the 600's on the outside of the pipe with an infra-red reader.  I'll keep experimenting for max efficiency.  Thanks again!  Curt


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## bholler (Nov 27, 2018)

ct01r said:


> Thanks guys!  I have single wall stainless.  It's been reading under 150 to 200 when I have the damper and air intake closed down (still has enough air leakage going in to keep the stove itself around 300-400 degrees).  When I open it up, the stove pipe reads in the 600's on the outside of the pipe with an infra-red reader.  I'll keep experimenting for max efficiency.  Thanks again!  Curt


Ir thermometers can be thrown off by refective surfaces.  Get a magnetic thermometer and run a screw through the hole in the middle.

And btw 150 to 200 is pretty low for the outside of single wall pipe if that is accurate.  Chances are you are dropping below 212 by the time it reaves the top of the chimney.  600 is to high for the surface of singlewall.


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## ct01r (Nov 28, 2018)

Thanks beholler!  I try to avoid the shiny spots to shoot so it's more accurate.  Good to know on the temperatures.  I'll fine tune the stove accordingly.


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