What Are Safe Flue Temps?

[AppalachianStan]

I am seeing 350* at 12" and 300* at 18" on my single wall stove pipe with ChimGard thermometer. At what temps should I be worried?

 

[HotCoals]

You're fine. When you see 800 or so then your pipe is getting hot.

 

[xtrordinair]

id be more worried when the pipe temps real low.Thats when the bad soot begins to collect.

 

[AppalachianStan]

I sealed up the joints on my stove pipe and cleaned the chimney today and this is the best this old stove has ran. It was up to 1400* but its holding at 1200* right now 2 hours in to the burn. And stove pipe is hold at 300* + for those 2 hours.

 

[HotCoals]

I know he's more on the low side then any where near the high side.

I'm running 300f 18" up right now also.
Actually I'm using my key damper to keep the wind from sucking more heat up the flue.
These temps are fine if the cat is in decent shape and the wood is dry and the pipe goes up through the house.

 

[AppalachianStan]

Cat is a year old, wood 15-19% and the pipe goes up through the house. I usually see 200* on my flue temps. I read here some where that you multiply by 2 for the magnet temp gauge.

 

[HotCoals]

Cat is a year old, wood 15-19% and the pipe goes up through the house. I usually see 200* on my flue temps. I read here some where that you multiply by 2 for the magnet temp gauge.

Yeah roughly twice..who knows.

Thing is as long as your flue stays decent just use the gauge for a reference point.
Thing is if you get wind chills of -20f like we are supposed to get tonight, most stoves will struggle. I would not recommenced force feeding any stove by burning extra hot.
Just turn the t-stat up on the furnace and be conformable.
It's a fools game to try and beat mother nature sometimes.

 

[AppalachianStan]

We are going to be down to 10* with the wind chill at -2. There is no furnace just wood stove and 2 infrared heaters.

 

[HotCoals]

We are going to be down to 10* with the wind chill at -2. There is no furnace just wood stove and 2 infrared heaters.

Well you must have a oven,maybe time to bake some cookies?
Might take your mind off the stove some..just sayin'. lol

 

[begreen]

This question gets asked a lot. The first thing to clarify is - are we talking about reading the surface or probe temps? Single wall pipe gets a surface thermometer, double-wall connector stove pipe gets a probe thermometer. For either pipe you want to avoid continuous, inside the pipe, temps over 900F. An occasional spike is ok, but you don't want to run it daily up to 1200. OK, then why does the reading differ? Surface temps are going to be cooler than the interior (probe) temps. Single wall pipe will cool down the gases more rapidly so you want to stay for surface temps you want to read about 18" above the stove. The surface readings will be about 30-50% cooler than the actual flue gas temps. That is why the range scales on a stove pipe thermometer start saying "Overfire" or "Too hot" starting around 500F. Try to keep the surface flue temps between 250 and 400during the peak of the burn cycle. Once the fire is at the coal only stage it's ok if the temps drift lower. The fire is past the creosote producing stage.

A properly placed and working probe thermometer is going to be more accurate because it's reading the actual flue gas temps. Too hot on a probe thermometer is above 900F. Don't panic if you get a spike above 900F actual (probe) temp when starting up a fire. Probe thermometers react faster because they are in the hot gases. As soon as you start cutting back the air the pipe temperature should start dropping. If you find that you are often spiking above the "Too hot" range, try burning down the coal bed a bit further and closing off the air once the fire is burning strongly, a little sooner. For normal burning, try to keep probe thermometer temps between 300 and 800 during the peak of the burn cycle.

Regardless of flue temps, remember that this is just a guide. The best instrument is your eyes. Don't be a slave to the thermometer. If the fresh fire is burning strongly, start turning it down, regardless of flue temps, until the fire starts getting lazy. Then let it buildup in intensity again and turn it down again until the flames start getting lazy. Repeat if necessary until the air control is nearly or all the way closed.

 

[AppalachianStan]

Thanks you all for the help. just want to make sure I not over fire tonight.
Begreen we are talking surface temps on single wall pipe. Way does Condar say to put the ChimGard thermometer at 12"?

 

[begreen]

Follow the mfg's recommendation. Note that they say "eye level", no less than 12"

Condar thermometers attach magnetically, directly to metal flue pipe. Optimal location is at eye level, no less than 12 inches above the top of the stove.

 

[HotCoals]

You would think you would have to be pretty short to have eye level at only 12" above the stove...or a high hearth I guess.

 

[begreen]

Exactly. 12" is their minimum. I prefer 18". It saves the beard from singeing.

 

[AppalachianStan]

Will I have 2 one at 12" and one at 18" playing around to see which one I like. I know at 18" in the pass it takes some time to get to 300*.the one at 12" I usually have for a stove top gauge.

Well you must have a oven,maybe time to bake some cookies? Might take your mind off the stove some..just sayin'. lol

Yeah that would be good. LOL

 

[AppalachianStan]

Getting up to 400* on stove pipe How do I cool it down when the air is close?