Fireview Flue Temp vs Stove Temp

[Randyb]

I'm new at this and was curing the stove and stumbled upon something I couldn't remember having already read here so here goes.

I got the stove top temp going to just below 300 and the pipe temp reading 325 and engaged the CAT and decreased the airflow to just dancing flames, the stove top temp continued to climb up to just over 350 but the pipe temp went down to around 225. So my question is, the pipe thermometer says that below around 260 is too low a temp for the exhaust going through the pipe, but the Fireview Cat is supposed to be really clean burning so if the pipe temps are to low is there still the strong risk of buildup or is that negated by how clean of a burn the Fireview is? Or, am I just doing something wrong with how I've done the first burn? Or am I just worried too much because I'm new at this?

The setup is:
Fireview connected to approximately 5.5' single wall 22GA into wall for 26" SS 6" with air insulated through an 8" SS (Thimble) into Tee and 22' of Ovalized 6" SS with insulated wrap in masonry chimney, the draft is pretty strong (IMO). I've attached the picture for reference, if anyone can shed some light or impart some knowledge it would be greatly appreciated. Thanks

(broken image removed)

 

[Randyb]

I meant to put this in the Hearth Room for better exposure and possible help, if someone could move it there it would be much welcomed. Thanks

 

[North of 60]

Ive sent for help. Should be moved shortly. Its a great example of a cat stove keepin the heat in. Awsome lookin stove and set up.

 

[begreen]

Moved to the hearth forum. The surface temp of the pipe is not the same as the interior temp. You should be fine and I expect will be building bigger fires soon. Hopefully Todd and NY Soapstone will chime in soon and post their typical temps for more guidance.

In the meantime, here is a discussion about the learning curve with this stove and some good suggestions for running it:
https://www.hearth.com/talk/threads/10453/

 

[3fordasho]

200-300F is typical flue temp for my Fireview after engaging the cat. I have a probe type thermometer in double wall pipe about 2' up from the top of the stove. Only have one season burning so far and had minimal build up in the chimney but I attribute that to unknown wood dryness more than anything. I expect less build up this season now that I know the history of the wood supply.


[quote author="RandyB" date="1218419776"]I'm new at this and was curing the stove and stumbled upon something I couldn't remember having already read here so here goes.

I got the stove top temp going to just below 300 and the pipe temp reading 325 and engaged the CAT and decreased the airflow to just dancing flames, the stove top temp continued to climb up to just over 350 but the pipe temp went down to around 225. So my question is, the pipe thermometer says that below around 260 is too low a temp for the exhaust going through the pipe, but the Fireview Cat is supposed to be really clean burning so if the pipe temps are to low is there still the strong risk of buildup or is that negated by how clean of a burn the Fireview is? Or, am I just doing something wrong with how I've done the first burn? Or am I just worried too much because I'm new at this?

The setup is:
Fireview connected to approximately 5.5' single wall 22GA into wall for 26" SS 6" with air insulated through an 8" SS (Thimble) into Tee and 22' of Ovalized 6" SS with insulated wrap in masonry chimney, the draft is pretty strong (IMO). I've attached the picture for reference, if anyone can shed some light or impart some knowledge it would be greatly appreciated. Thanks

 

[Backwoods Savage]

I'd say you are just fine. That's about what we are running in ours too and have had absolutely no problems. The cat. is working and you have good flame, so there should be nothing to worry about.

btw, we burned all of last winter without cleaning the chimney once. Simply put, there is no creosote, but we did knock about a cup full of soot down from the top. We're ready to burn again this fall, which is coming fast.

Really like your setup. Nicely done!

 

[Todd]

This is just a breakin fire right? Pretty typical for this stove. When the bypass is open the heat goes straight up the flue and when you engage the cat most of the heat stays in the stove and the pipe will cool down. I have monitored both external and internal temps on my stove and have found with single wall the internal temp is roughly double the external at about 18" above the stove. With my stove top at 600 my external pipe temp runs 250-300 and internal 500-600. I use to run a little higher temps and I think my chimney was slightly overdrafting so I installed a pipe damper and the temps dropped a little.

 

[Todd]

200-300F is typical flue temp for my Fireview after engaging the cat. I have a probe type thermometer in double wall pipe about 2' up from the top of the stove. Only have one season burning so far and had minimal build up in the chimney but I attribute that to unknown wood dryness more than anything. I expect less build up this season now that I know the history of the wood supply.

200-300 internal probe temp? Seems low to me? What is your stove top temp during this? My internal pipe temp doesn't run that low til the fire reaches the coaling stage.

 

[3fordasho]

200-300F is typical flue temp for my Fireview after engaging the cat. I have a probe type thermometer in double wall pipe about 2' up from the top of the stove. Only have one season burning so far and had minimal build up in the chimney but I attribute that to unknown wood dryness more than anything. I expect less build up this season now that I know the history of the wood supply.

200-300 internal probe temp? Seems low to me? What is your stove top temp during this? My internal pipe temp doesn't run that low til the fire reaches the coaling stage.

Yes. Stove top will be 400-550F. The internal pipe temp is never over 300F with the cat engaged. 200-250F is pretty typical.
I suppose there is alot of variance in these thermometers, I started with a condor "probe type" but it was really just a steel rod that transferred the heat to a bimetallic coil that was right behind the face. Didn't work right (read way too low and slow to react) because I was using in a adjustable section of double wall pipe which is actually 4 thicknesses of metal. The readings above are with a true probe type thermometer that seems pretty accurate but I havn't actually checked it. I believe it was rated at +/-5% of full scale (1000F full scale).

 

[Todd]

200-300F is typical flue temp for my Fireview after engaging the cat. I have a probe type thermometer in double wall pipe about 2' up from the top of the stove. Only have one season burning so far and had minimal build up in the chimney but I attribute that to unknown wood dryness more than anything. I expect less build up this season now that I know the history of the wood supply.

200-300 internal probe temp? Seems low to me? What is your stove top temp during this? My internal pipe temp doesn't run that low til the fire reaches the coaling stage.

Yes. Stove top will be 400-550F. The internal pipe temp is never over 300F with the cat engaged. 200-250F is pretty typical.
I suppose there is alot of variance in these thermometers, I started with a condor "probe type" but it was really just a steel rod that transferred the heat to a bimetallic coil that was right behind the face. Didn't work right (read way too low and slow to react) because I was using in a adjustable section of double wall pipe which is actually 4 thicknesses of metal. The readings above are with a true probe type thermometer that seems pretty accurate but I havn't actually checked it. I believe it was rated at +/-5% of full scale (1000F full scale).

I have the Condar probe with the bimetallic coil thingy. I wonder if my temps are still too high? I'm going to call Woodstock and get the skinny.

 

[burntime]

That thing is blazing like it should. If the chimney is clean, your burning dry wood, and all the connections are tight I would not worry. Looks good!

 

[3fordasho]

200-300F is typical flue temp for my Fireview after engaging the cat. I have a probe type thermometer in double wall pipe about 2' up from the top of the stove. Only have one season burning so far and had minimal build up in the chimney but I attribute that to unknown wood dryness more than anything. I expect less build up this season now that I know the history of the wood supply.

200-300 internal probe temp? Seems low to me? What is your stove top temp during this? My internal pipe temp doesn't run that low til the fire reaches the coaling stage.

Yes. Stove top will be 400-550F. The internal pipe temp is never over 300F with the cat engaged. 200-250F is pretty typical.
I suppose there is alot of variance in these thermometers, I started with a condor "probe type" but it was really just a steel rod that transferred the heat to a bimetallic coil that was right behind the face. Didn't work right (read way too low and slow to react) because I was using in a adjustable section of double wall pipe which is actually 4 thicknesses of metal. The readings above are with a true probe type thermometer that seems pretty accurate but I havn't actually checked it. I believe it was rated at +/-5% of full scale (1000F full scale).

I have the Condar probe with the bimetallic coil thingy. I wonder if my temps are still too high? I'm going to call Woodstock and get the skinny.

That's what I had, read way too low on my piping set up and very slow to react. Now I'm using a teltru industial probe type 2" dial thermometer 200-1000F. The bi-metalic coil is in the probe. Just checked the website (www.teltru.com) and acuracy is actually +/-1% of full scale. Cost was just little over $30 and I actually trust what it reads.

 

[Todd]

200-300F is typical flue temp for my Fireview after engaging the cat. I have a probe type thermometer in double wall pipe about 2' up from the top of the stove. Only have one season burning so far and had minimal build up in the chimney but I attribute that to unknown wood dryness more than anything. I expect less build up this season now that I know the history of the wood supply.

200-300 internal probe temp? Seems low to me? What is your stove top temp during this? My internal pipe temp doesn't run that low til the fire reaches the coaling stage.

Yes. Stove top will be 400-550F. The internal pipe temp is never over 300F with the cat engaged. 200-250F is pretty typical.
I suppose there is alot of variance in these thermometers, I started with a condor "probe type" but it was really just a steel rod that transferred the heat to a bimetallic coil that was right behind the face. Didn't work right (read way too low and slow to react) because I was using in a adjustable section of double wall pipe which is actually 4 thicknesses of metal. The readings above are with a true probe type thermometer that seems pretty accurate but I havn't actually checked it. I believe it was rated at +/-5% of full scale (1000F full scale).

I have the Condar probe with the bimetallic coil thingy. I wonder if my temps are still too high? I'm going to call Woodstock and get the skinny.

That's what I had, read way too low on my piping set up and very slow to react. Now I'm using a teltru industial probe type 2" dial thermometer 200-1000F. The bi-metalic coil is in the probe. Just checked the website (www.teltru.com) and acuracy is actually +/-1% of full scale. Cost was just little over $30 and I actually trust what it reads.

So your old Condar probe was running even lower than your current probe? Maybe my internal probe is way off, I'll have to do an oven test and see?

 

[3fordasho]

200-300F is typical flue temp for my Fireview after engaging the cat. I have a probe type thermometer in double wall pipe about 2' up from the top of the stove. Only have one season burning so far and had minimal build up in the chimney but I attribute that to unknown wood dryness more than anything. I expect less build up this season now that I know the history of the wood supply.

200-300 internal probe temp? Seems low to me? What is your stove top temp during this? My internal pipe temp doesn't run that low til the fire reaches the coaling stage.

Yes. Stove top will be 400-550F. The internal pipe temp is never over 300F with the cat engaged. 200-250F is pretty typical.
I suppose there is alot of variance in these thermometers, I started with a condor "probe type" but it was really just a steel rod that transferred the heat to a bimetallic coil that was right behind the face. Didn't work right (read way too low and slow to react) because I was using in a adjustable section of double wall pipe which is actually 4 thicknesses of metal. The readings above are with a true probe type thermometer that seems pretty accurate but I havn't actually checked it. I believe it was rated at +/-5% of full scale (1000F full scale).

I have the Condar probe with the bimetallic coil thingy. I wonder if my temps are still too high? I'm going to call Woodstock and get the skinny.

That's what I had, read way too low on my piping set up and very slow to react. Now I'm using a teltru industial probe type 2" dial thermometer 200-1000F. The bi-metalic coil is in the probe. Just checked the website (www.teltru.com) and acuracy is actually +/-1% of full scale. Cost was just little over $30 and I actually trust what it reads.

So your old Condar probe was running even lower than your current probe? Maybe my internal probe is way off, I'll have to do an oven test and see?

Yes, but I attribute that to the location in the adjustable section of double wall pipe. I believe the condor probe thermometer is set up for double wall pipe, but I effectively had 4 thicknesses of metal and it threw off the reading. The teltru thermometer has the
coil inside the probe which is right in the flue stream. With the condor thermometer the readings were always way low, even with the cat bypassed and I knew flames were going a ways up the pipe (start up). The teltru will quickly read 600F+ in this situation and I quickly know to start cutting air.

 

[begreen]

Thanks for the link 3fordasho. Which model Tel-Tru are you using? Where did you pick it up?

I like the Tel-Tru DM-014-750 surface thermometer. It is the first model I've seen with clear black on white markings and a glass cover. That is my kind of stove thermometer. It matches my trusty old Sandhill.

 

[Todd]

Well my probe is junk! I just tested it in a 500 degree oven and it pegged at 1800! What the hell! I had my external magnetic thermometer right next to it and it was right on. This is my 3rd internal probe. I had the one from Woodstock that went directly to the cat and it lasted about 2 months, then I went to the digital condar probe and I couldn't even get that one to give a reading so it got sent back. Now this one is bad. I'm sticking with the external magnetic.

 

[3fordasho]

Thanks for the link 3fordasho. Which model Tel-Tru are you using? I like the Tel-Tru DM-014-750 surface thermometer. It is the first model I've seen with clear black on white markings and a glass cover. That is my kind of stove thermometer. It matches my trusty old Sandhill.

Tel-tru #4910 02 66 which translates to model GT225 2" dial, 1/8npt thread, 2 1/2" probe length, 200/1000F scale

 

[begreen]

Thanks. Where did you pick it up? It looks like the local listed dealer is no more.

 

[3fordasho]

Well my probe is junk! I just tested it in a 500 degree oven and it pegged at 1800! What the hell! I had my external magnetic thermometer right next to it and it was right on. This is my 3rd internal probe. I had the one from Woodstock that went directly to the cat and it lasted about 2 months, then I went to the digital condar probe and I couldn't even get that one to give a reading so it got sent back. Now this one is bad. I'm sticking with the external magnetic.

You might want to try a tel-tru thermometer. I think the condor probe type uses heat transfer to the bi metal coil thru both the solid steel probe and the outside wall of the flue pipe so heating the entire thermometer in an oven may not be valid test of its
accuracy. As far as I can tell there is no way to test it for accuracy so I got rid of mine.

 

[3fordasho]

Thanks. Where did you pick it up? It looks like the local listed dealer is no more.

Direct from tel-tru. Thought they had an online order system when I got mine but don't see it now, looks like they've been
reworking the site a bit. Think I paid around $32 + $6.5 shipping or so.

 

[3fordasho]

Thanks for the link 3fordasho. Which model Tel-Tru are you using? I like the Tel-Tru DM-014-750 surface thermometer. It is the first model I've seen with clear black on white markings and a glass cover. That is my kind of stove thermometer. It matches my trusty old Sandhill.

Tel-tru #4910 02 66 which translates to model GT225 2" dial, 1/8npt thread, 2 1/2" probe length, 200/1000F scale

Upon further review it appears I actually purchased a model GT200 (#1910 02 66) which has all the same specs, just a 1 3/4" face instead of the 2". I'm sure the 2" is a few bucks more ;-)

 

[Randyb]

So when you use an internal probe type are you drilling a hole in the pipe? Do you then leave it there? If not, does the open hole cause any concerns with safety or drafting? Thanks for all the great information, I'm glad to see it seems to be working as it is supposed to.

 

[3fordasho]

So when you use an internal probe type are you drilling a hole in the pipe? Do you then leave it there? If not, does the open hole cause any concerns with safety or drafting? Thanks for all the great information, I'm glad to see it seems to be working as it is supposed to.

Yes I drilled a hole in the pipe, the only time the thermometer comes out is when I'm cleaning the chimney.

 

[madison]

Thanks for the link 3fordasho. Which model Tel-Tru are you using? I like the Tel-Tru DM-014-750 surface thermometer. It is the first model I've seen with clear black on white markings and a glass cover. That is my kind of stove thermometer. It matches my trusty old Sandhill.

Tel-tru #4910 02 66 which translates to model GT225 2" dial, 1/8npt thread, 2 1/2" probe length, 200/1000F scale

Upon further review it appears I actually purchased a model GT200 (#1910 02 66) which has all the same specs, just a 1 3/4" face instead of the 2". I'm sure the 2" is a few bucks more ;-)

FYI, i spoke with the technical rep at Tel Tru, and they informed me that the GT series thermometers (and all of their units) could possibly fail over 800 degrees, specifically the steel probe would harden then crack.

I was curious if there are any long term users that could report on this thermometer's durability.

Thanks

 

[3fordasho]

Thanks for the link 3fordasho. Which model Tel-Tru are you using? I like the Tel-Tru DM-014-750 surface thermometer. It is the first model I've seen with clear black on white markings and a glass cover. That is my kind of stove thermometer. It matches my trusty old Sandhill.

Tel-tru #4910 02 66 which translates to model GT225 2" dial, 1/8npt thread, 2 1/2" probe length, 200/1000F scale

Upon further review it appears I actually purchased a model GT200 (#1910 02 66) which has all the same specs, just a 1 3/4" face instead of the 2". I'm sure the 2" is a few bucks more ;-)

FYI, i spoke with the technical rep at Tel Tru, and they informed me that the GT series thermometers (and all of their units) could possibly fail over 800 degrees, specifically the steel probe would harden then crack.

I was curious if there are any long term users that could report on this thermometer's durability.

Thanks

I've only used mine for one season (although I did find out about these thermometers from another user on this forum) and no problems. I was aware that continuous use up to 800F is ok, with only intermittent use above 800f. With my stove and burning habits I really found no need to get much over 600F flue temps, I'll run at about 600F to char a new load, then with the cat engaged 200-275f is the normal operating range.