Max Flue Gas Temp

[cmcramer]

About to install a probe thermometer through new double walled stovepipe, to replace a magnetic thermometer on outside of single walled pipe.

If the flue gas temp is about double the temp on the outside of single wall pipe, and my Dealer says to not exceed 550 on the outside of single wall, can I assume my probe thermometer readings should be kept under 1100? Is 1100 safe?

I am asking because some other threads here seem to indicate that flue gas at 1000 is a "Yikes!" type of condition. Thanks!

 

[mikepinto65]

yikes for me is 1200, and even then my eyes arnt bulging.....but I am closing the primary air down quickly.

 

[WoodMann]

Personally that's a bit out of my comfortzone. I run at around 6 to 700*. I like to kick things off and nip at 1000* for a few and gradually back down to cruising temperature; dang I sound like and airline pilot, eh...................

 

[mikepinto65]

Personally that's a bit out of my comfortzone. I run at around 6 to 700*. I like to kick things off and nip at 1000* for a few and gradually back down to cruising temperature; dang I sound like and airline pilot, eh...................

I should have added the point that 1200 is my spike temp when getting the fresh load going....from than on my cruising temps range from 700-900 (which i cannot get to go lower and have grown accustom to).

 

[Highbeam]

Your flue temp probe meter has the temps of concern right on it. You got the condar right? Keep it out of the red which is listed as overfire.

Incidentally, this is a manufacturer question. The pipe is rated for a certain temp which is 1000 continuous and 2100 intermittent on simpson class A.

I regularly bump 1000 on startup and then cruise in the 700-800 range with stovetop at about 400. I actually really want to hit that max daily to keep things cleaned out.

 

[Corey]

I guess you could use it as a guide, but why would flue gas at even 1200F be any cause for concern in a pipe which is rated 2100F +? Even if the pipe was as hot as the gas - which is pretty unlikely - you're still barely half the rated temperature.

 

[mikepinto65]

I guess you could use it as a guide, but why would flue gas at even 1200F be any cause for concern in a pipe which is rated 2100F +? Even if the pipe was as hot as the gas - which is pretty unlikely - you're still barely half the rated temperature.

I agree, my concerns mostly came from reading the ridiculous low temps people here claim....although, low internal flue temps can really only mean one thing....lower internal stove temperatures....which is worse??!!??

 

[Highbeam]

Good question. I see the 1000 continuous rating as the normal max but that it can run up to 2100 during a chimney fire. So the pipe isn't rated for 2100, it is rated for 1000. Apparently condar sees it the same way.

 

[Corey]

That is a good point Highbeam, but I would still suggest the pipe material temp is still much lower than the flue gas temp. There is a relation, but definitely not equal.

 

[ckdeuce]

About to install a probe thermometer through new double walled stovepipe, to replace a magnetic thermometer on outside of single walled pipe.

If the flue gas temp is about double the temp on the outside of single wall pipe, and my Dealer says to not exceed 550 on the outside of single wall, can I assume my probe thermometer readings should be kept under 1100? Is 1100 safe?

I am asking because some other threads here seem to indicate that flue gas at 1000 is a "Yikes!" type of condition. Thanks!

I have a similar post running....... I see 700 - 1000 all day long. Scary, but I am learning from others that it might not be a bad thing....

 

[oconnor]

That is a good point Highbeam, but I would still suggest the pipe material temp is still much lower than the flue gas temp. There is a relation, but definitely not equal.

To be more specific, the pipe isn't rated to 1000*F temps, the pipe is rated to contain flue gasses that are at 1000*F continuous, and 2100*F for 1 hour after which you need to replace the pipe - the pipe will obviously be cooler, the gasses are not, and the ratings and testings are done based on flue gas temps, not surface temps of the pipes.

 

[Corey]

Wow - The pipe is not even supposed to run 1000F? If that's really the case, I'd throw that pipe out the door and get something worth a cent!

Coming right off the stove, my stainless liner has a dark purple color. Comparing that to the heat tint tables, it looks to be around 850ºF. So I know the pipe has been to that temp before. Admittedly, that is with some pretty hard burning, though. I don't have a probe in the stack, but I imagine the gas temp would need to be much hotter to get the steel to 850º in open air.

 

[mikepinto65]

If your getting heat tint readings of 850 °F wouldn't that mean the internal gas temperature actually hit at least 1700 °F ?

Edit:
Sorry just read the last sentence, looks like you already figured that out :blank:
Good to know it didnt melt!

 

[soupy1957]

I'd like to approach the original question from another point of view.........I have double-wall flue pipes............My intent is to put a magnetic thermostat on the pipe, but I'm wondering if it will effectively read the temp of the gases, since it is on the "outer" pipe??????

Is there a better choice of tool for accurate temp readings on double-tube flue pipes, if the magnetic one is not going to give me accurate reads?

-Soupy1957

 

[Troutchaser]

Soupy,
I'm installing a Condar probe into my double wall tonight. Does anyone have experience with this? Drill a hole and insert? I don't mess with stuff like this much and I don't want to bugger up our pretty black pipe.

To the best of my knowledge, there is no way to accurately measure internal flue temps outside a double wall pipe. Too many variables.

 

[soupy1957]

Burning Chunk:
-It's gonna sound like a cop out, but ..........follow the recommended installation instructions that came with your new Condar.
-Am I misreading some of the threads, or are some folks using the magnetic thermometers on the top of the stove itself?
-Soupy1957

 

[Pagey]

I use a magnetic on the stove top. A magnetic on the surface of a double wall stove pipe will tell you almost nothing of value, unfortunately.

 

[cmcramer]

My new Selkirk Double Wall Stovepipe just arrived and instructions say "..(for) appliance normally producing flue gases of 1200 F (Canada) or 1000 F (USA.)

Obviously, differing safety standards in Canada vs USA....

I live in Upstate NY near the border, so I'm keeping my flue temp at 1100 F or under.........

 

[oconnor]

Wow - The pipe is not even supposed to run 1000F? If that's really the case, I'd throw that pipe out the door and get something worth a cent!

Coming right off the stove, my stainless liner has a dark purple color. Comparing that to the heat tint tables, it looks to be around 850ºF. So I know the pipe has been to that temp before. Admittedly, that is with some pretty hard burning, though. I don't have a probe in the stack, but I imagine the gas temp would need to be much hotter to get the steel to 850º in open air.

Check out his wiki page on steel temps - https://www.hearth.com/econtent/index.php/wiki/Stainless_Steel

According to this link stainless steel will appear to glow red in sunlight at 1000*F steel temp, so obviously, no, the pipe is not supposed to run 1000*F, as you shouldn't let it glow red enough to be visible in sunlight.

 

[Highbeam]

Soupy,
I'm installing a Condar probe into my double wall tonight. Does anyone have experience with this? Drill a hole and insert? I don't mess with stuff like this much and I don't want to bugger up our pretty black pipe.

To the best of my knowledge, there is no way to accurately measure internal flue temps outside a double wall pipe. Too many variables.

Might be too late, you guys and your time zones, but I just followed the directions to install the condar probe meter into the pipe. One special trick.... drill the small hole all the way through both walls first, then enlarge the outer hole with the second and larger bit. This method will ensure that the holes are concentric.

Funny thing about double wall pipe is that the inner shell expands at a different rate than the outer shell so your probe meter will actually point towards the ceiling when the flue is hot. Only way to counter this is to drill the holes when the flue is up to running temp and then risk the thing pointing at the ground all summer long!

You need a probe meter to properly measure flue temps in all cases. You can get by with a magnetic meter for single wall but not with double wall. I use a surface temp gauge for my stove top as required by the owner's manual.

 

[soupy1957]

"Funny thing..........................your probe meter will actually point towards the ceiling when the flue is hot."

That makes perfect sense.............to a guy!!

-Soupy1957

 

[Highbeam]

That does have some rather R-rated second meaning doesn't it? Freaking hilarious to read it that way, good job!