Checking Flue Temperature

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rbiebr

New Member
Dec 17, 2022
10
Pennsylvania
How can I check flue temperature on a wood burning insert with surround trim installed. I see that most of you guys use probe type in the flue. but with the insert and trim kit I have no visual access to the flue pipe. Is there a probe type insert that works wireless, that would allow me to see the temperature. I have a insulated double wall SS liner.
 
How can I check flue temperature on a wood burning insert with surround trim installed. I see that most of you guys use probe type in the flue. but with the insert and trim kit I have no visual access to the flue pipe. Is there a probe type insert that works wireless, that would allow me to see the temperature. I have a insulated double wall SS liner.
Auber instruments makes units that will work
 
You need a hole, probably in the appliance adapter. The probe will have a wire that you can run out under/around the surround and plug into the Auber unit. My appliance adapter had a hole already. I don’t know if a wireless probe unit. Auber makes the AT210 that has a wireless remote duplicate displays but the sending display unit would have to be behind the insert and it might get too hot.
 
Auber AT100. See my old thread, still works today: https://www.hearth.com/talk/threads/digital-cat-probe.105221/post-2035527

I tried both the magnetic and the washer probes and found the washer probe was more consistent. The washer probe doesn't "need" to be screwed in, but it helps, I slipped it in to the appliance adapter at the top in-between it and the flex liner, it was a very snug fit and didn't move.
 
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I would honestly just go with a surface sensor. You would have to pull the probe every time you clean otherwise
 
If you go with the washer probe without screwing it in you do not need to remove it for cleaning and it usually stays in very well. It slides right in and gives a good idea on exit temps, the cord allows you to have the AT100 mounted outside the shroud.

I found exhaust temps to be the best to monitor, especially for the high temp alarm found on the AT100.
 
I slipped it in to the appliance adapter at the top in-between it and the flex liner, it was a very snug fit and didn't move.
I assume that on a rear-vent setup (rear exit into a tee, then flex liner) in a masonry fireplace like mine, the hottest place to put the washer would be on the rear of the tee, where flame heat would hit when it goes from horizontal to vertical in the tee?
I guess I could just use one of the screws that fasten the liner to the tee...does that sound good?
Right now, I just have a surface meter on top of the tee snout, about 6" back from the flue exit, but I like the idea of being able to see it without going over there. 😏

[Hearth.com] Checking Flue Temperature
 
I assume that on a rear-vent setup (rear exit into a tee, then flex liner) in a masonry fireplace like mine, the hottest place to put the washer would be on the rear of the tee, where flame heat would hit when it goes from horizontal to vertical in the tee?
I guess I could just use one of the screws that fasten the liner to the tee...does that sound good?
Right now, I just have a surface meter on top of the tee snout, about 6" back from the flue exit, but I like the idea of being able to see it without going over there. 😏

View attachment 305658
In my experience all the temps no matter the location are relative readings ( unless flue probe is 18” above The outlet) Once you self calibrate to what you see and hear and what the temp reading is the hottest location isn’t that important. It is nice being able to read the 1” tall numbers without getting up or just when walking by.
 
Auber AT100. See my old thread, still works today: https://www.hearth.com/talk/threads/digital-cat-probe.105221/post-2035527

I tried both the magnetic and the washer probes and found the washer probe was more consistent. The washer probe doesn't "need" to be screwed in, but it helps, I slipped it in to the appliance adapter at the top in-between it and the flex liner, it was a very snug fit and didn't move.
Auber AT100. See my old thread, still works today: https://www.hearth.com/talk/threads/digital-cat-probe.105221/post-2035527

I tried both the magnetic and the washer probes and found the washer probe was more consistent. The washer probe doesn't "need" to be screwed in, but it helps, I slipped it in to the appliance adapter at the top in-between it and the flex liner, it was a very snug fit and didn't move.
Thank you for the info. This set up is what i am looking for. What do you do with the AT100, mount it somewhere near the stove. Looks like might be limitations due to length of wire.

With todays technology I would think that there would be some type of sensing device that could be linked with an app which would allow monitoring temperature from the recliner or anywhere your travels take you
 
Thank you for the info. This set up is what i am looking for. What do you do with the AT100, mount it somewhere near the stove. Looks like might be limitations due to length of wire.

With todays technology I would think that there would be some type of sensing device that could be linked with an app which would allow monitoring temperature from the recliner or anywhere your travels take you
You can get up to 25’ long wire. (I think) Wireless units and high temps. You can set up an up web cam pointed at the unit if you really wanted to monitor from anywhere. Never felt the need. The wireless 210 lets me look at my downstairs temp from up stairs that’s good enough for me.
 
With todays technology I would think that there would be some type of sensing device that could be linked with an app which would allow monitoring temperature from the recliner or anywhere your travels take you

Auber has Wifi units that you can read your temps online, plenty of threads on here about doing that kind of stuff, the AT100 has been with me for almost 10 years now and still going. The thermocouple cord is longer than you would think, I find it plenty long to have the device mounted on the outside of the insert shroud.
 
I assume that on a rear-vent setup (rear exit into a tee, then flex liner) in a masonry fireplace like mine, the hottest place to put the washer would be on the rear of the tee, where flame heat would hit when it goes from horizontal to vertical in the tee?
I guess I could just use one of the screws that fasten the liner to the tee...does that sound good?
Right now, I just have a surface meter on top of the tee snout, about 6" back from the flue exit, but I like the idea of being able to see it without going over there. 😏
This was the view from my couch, I can clearly see the temps while watching tv. Plus the Hi Temp alarm set at 800 has saved my butt many times. As mentioned once you pick a spot you know what temps to look for, its just a gauge for how your burn is doing and if you need to reload.

[Hearth.com] Checking Flue Temperature
 
In my experience all the temps no matter the location are relative readings ( unless flue probe is 18” above The outlet) Once you self calibrate to what you see and hear and what the temp reading is the hottest location isn’t that important.
As mentioned once you pick a spot you know what temps to look for, its just a gauge for how your burn is doing and if you need to reload.
Makes sense. I'm considering putting a probe into the liner to get the quicker response of it being in the exhaust stream..
 
I fr
Makes sense. I'm considering putting a probe into the liner to get the quicker response of it being in the exhaust stream..
I fret more over my flue temp probe and tend make more adjustments but it’s a new stove. I could probably run the flue probe closer to the low burn rate but that really doesn’t gain much. If your liner is insulated try sticking it up between the liner and insulation.
 
If your liner is insulated try sticking it up between the liner and insulation.
I hadn't thought of that...yep, 1/2" insulation on that liner.
 
I hadn't thought of that...yep, 1/2" insulation on that liner.
Get the probe on the standard length wire. You at least have options where to install.
 
Arduino + MAX6675 temp module + Type K thermocouple at the stove, then bluetooth that data to a wireless / rechargeable base station at your favorite arm chair. Flue is running 352°F

View attachment 305926
Very retro and cool with the nixie tubes.
 
Thanks. Guess if you need 'C', you could always add a line of code to the arduino for the '-32/1.8' part, and swap in an IN-19A tube in the last slot to show '°C', instead of the IN-19B which shows 'F'.