Am I Going To Burn My House Down???

[Woody Stover]

This stove has been in a fireplace for eight seasons and has never seen a flue thermometer. Only on the stove top.

The stove temp and flue temp don't always parallel each other, as you know. Sure, I can tell by looking in the box if that particular fire is going to heat up the flue faster than the box, but I still like having both meters....

 

[branchburner]

An external temp a few inches up a flue pipe tells you not one damned thing about the temp just a few feet more up that chimney. What you want to know is that the stuff in that box is burning, not going up and lining your chimney.

But you also want to know your heat is not all going up the chimney. On my stove, that external temp a few inches up a flue pipe can be 1000f while my stove top is still around 500f... lets me know, probably about time to shut the bypass.

 

[tsruggles]

The stove temp and flue temp don't always parallel each other, as you know. Sure, I can tell by looking in the box if that particular fire is going to heat up the flue faster than the box, but I still like having both meters....

I don't mind having them myself. I'm just trying to figure out how much grace there are with those readings. But should you walk over to the stove and look at the flue temp to see how the stove is doing????

 

[BrotherBart]

Just had a night load take off, as happens sometimes, to around 825 stove top. The last thing on my mind was what was happening in that liner rated for 1,000 degrees continuous and 2,100 periodic. What would it tell me? What could I do about it?

I had everything I needed to know right there in front of me.

 

[BrotherBart]

I don't mind having them myself. I'm just trying to figure out how much grace there are with those readings. But should you walk over to the stove and look at the flue temp to see how the stove is doing????

No.

 

[BrotherBart]

But you also want to know your heat is not all going up the chimney. On my stove, that external temp a few inches up a flue pipe can be 1000f while my stove top is still around 500f... lets me know, probably about time to shut the bypass.

That bypass should have been closed long before stovetop was 500 anyway.

 

[Woody Stover]

Condar makes a different thermometer with a different scale on it specifically for the stove pipe. That's where other manufacturers fail (like rutland) in that their scale is an average of both places, rather than specific to where it is being used.

I've got all Condars on everyone's stove, but I picked up the jumbo Meeco at the farm store at one point and put it on one of my BIL's stoves. I stole it back though....it's easy to see in my setup, lying on the tee take-off back in the fireplace.
I pretty much ignore the 'zone' designations, and focus on the temp. This is about the least obnoxious-looking Condar or Rutland I've seen:

 

[pen]

I've got all Condars on everyone's stove, but I picked up the jumbo Meeco at the farm store at one point, and put it on one of my BIL's stoves. I took it back though....it's easy to see in my setup, lying on the tee take-off back in the fireplace.
I pretty much ignore the 'zone' designations, and focus on the temp. This is about the least obnoxious-looking Condar or Rutland I've seen:
View attachment 125594

Exactly, looks are one thing, accuracy is another, and the burn zones are yet another factor.

I hate the rutlands mostly because I had 3 fail in short order personally, but also because that averaged temperature scale could cause an inexperienced burner to consistently run their stove too cool for fear that they were overfiring things based on the craptastic scale. As a consequence, creosote deposits in the chimney, increased risk of a chimney fire, poor heating capabilities, throwing things into snow banks, etc.

My cousin made a brand new chimney (double wall up to the appropriate thimble, and class A from there up) GLOW near the thimble (I'm still impressed that this is even possible) on his first fire of the season after moving this stove and putting a new chimney up this fall.

What scared him about the scenario is he had started the stove as he had last season and the stove top wasn't even to 400 yet when this happened. (Is a coal stove burning wood in it).

I brought him a probe thermometer that I do not use because of the aesthetics and had him insert it. It changed the way he burned significantly on start-up for the better.

Point is, all thermometers if accurate, measure temp at a given place. It's up to the user to use what information they have to ensure what they are doing is safe regardless of what that thermometer says. The problem comes with the learning curve to get there, and that some installations allow less opportunity for measuring devices to help with this.

As BB said, the pipe thermometer might be the way of the manual typewriter, however, with a cruising stove, it reads correctly (if placed in the right position). My grandfather's thermometer he purchased some time decades ago still reads accurately on the pipe, however, somewhere along the line, he learned that it may read a bit higher than the safe zone on on startup and to not pay attention to it then, what was important for his way of running that stove was what it read during a cruise situation (he never ran a stove top thermometer).

Since this all becomes rather commonplace with experience, it's easy to become dismissive. However, I have a lady at home who is willing to run the stove when I'm gone and I do what I can to make sure things are safe and easy for her (and for me so I don't get a phone call in the night when I'm gone!). That said, I installed a condar flue meter that looks like this

(broken image removed)

and placed it up the pipe so that when the stove top thermometer reads "redline" AT CRUISE this does as well. The two have been consistent for 3 years now. Not all setups have this availability, but mine does so I use it. By setting it this way, it easily lets me or the Mrs. know if things are firing too quickly and the stove pipe is getting too hot before the stove warms up, or the opposite, if we turn the air down too soon and the pipe starts to cool while the stove is too hot letting us know things are about to stall.

In all, it's a learning curve but I'm of the opinion if the setup allows more room for more information to be gathered, then have at it.

I have an IR thermometer that I like to use to verify things, but for checking on the stove while running past it 20x in the morning while it's warming up and we are getting ready for work, school, etc., or when fixing dinner in the evening, it's a pain in the rear to use compared to a magnetic that is always there and easy to glance at.

pen

 

[branchburner]

That bypass should have been closed long before stovetop was 500 anyway.

Welcome to my world... not even close. I live in Harman downdraft world, remember? From a cold stove I can hit 500 before I have squat for coals, let alone a bed. But takes a long time for the flue to heat up, relative to the stove top. On a hot reload, just the opposite: the flue temps explode before the stove top has a chance to change much.

 

[branchburner]

But should you walk over to the stove and look at the flue temp to see how the stove is doing????

IR gun... let your fingers do the walking.

 

[branchburner]

No.

"But should you walk over to the stove and look at the flue temp to see how the stove is doing????"

Kind of like walking over to see how the baby is doing. She's SLEEPING, of course...uh... WAS sleeping.

At least you can't make the stove cry by going over to see how cute she is.

 

[dafattkidd]

Hello all!

I've been doing a lot of research here and have found some great information! Thank you all for your knowledgeable contributions!

I'll get right to the point. I have a new Jotul F55. It's an amazing stove! It's installed in a brick fireplace that's fitted with a 6" stainless liner. The brick chimney is about 3' x 2' with the liner running up the center of the cavity. I have the stove rear vented directly into a 90 and up about a foot of black pipe to the liner.

After reading the forums I determined that the stovepipe thermometer had to get thrown into a snowbank. If I were to let the stove operation continue to be dictated by the stovepipe readings I fear that I would be wasting wood while being cold and allowing creosote to build up.

I have since been asked (commanded) to go dig the thermometer out of the snow and reinstall it. I have refused to since I feel that operating the stove within the parameters of the "safe" zone is not doing us any big favors. As soon as the needle comes within a quarter inch of the "call the fire department and evacuate the house" red zone, it gets turned down despite the fact that the stove is still under 500 degrees.

I just feel that a steel tube inside of a brick chimney could probably sustain the blue blazes of the underworld surging through it for an hour or so...... much less the heat from a really nice stove.

You all probably know why I'm posting this question. Please, feel free to inquire about more specifics relating to my current setup. I just think that it would be helpful to all forum readers (especially me) to be able to assess exactly how much risk I run by not using that darn thermometer.

Please folks, help a guy out here. If you need pictures, I'll take them. More info? I'll give it to you! I could use all of the advice that I can get (all right here in a convenient single thread that I can easily review with loved ones). Otherwise I'm probably going to be residing with the thermometer in that snowbank soon.

Just for the sake of redundancy: These units are designed to be run HOT. Keep your stove top above 500. Burning hot and clean keeps your chimney clean, burns most efficiently and keeps your stove from gunking up the neighborhood. The best indicators for a modern woodburning unit are a stove top thermometer, keeping an eye on the inside of the firebox and watching the top of the chimney to make sure no smoke is pouring out. Good luck!

 

[Nick Mystic]

After reading through all the comments I'm a bit surprised that nobody has commented on tsruggles flue set up since his wife is concerned with safety and fears a chimney fire. He says he comes out the back of his stove with a 90 and then a foot of stove pipe straight up to connect with his flex liner. It's been my experience that using a 90 elbow, rather than a T-connector in this sort of installation increases your chances of a chimney fire. With a 90 elbow any creosote that flakes off the stove pipe or flex liner falls down into the elbow where it builds up in a small pile that will eventually affect the draft if it gets big enough. It is also sitting in a spot that greatly increases the likelihood that it will catch fire if the stove starts burning too hot. With a T-connector set up any creosote that falls down the liner gathers in the bottom of the T-connector in the clean out cap where it is out the direct path of any flame or super hot exhaust gas/smoke.

 

[firefighterjake]

Fan of thermometers . . . both for the stove and the flue . . . if they are reasonably close to the proper reading . . . and as long as any color coding actually matches up to what is Bad and Good in terms of burning and temps.

I tend to use my probe style Condar more often to run the stove than I do the stove thermo . . . it is what works for me.

 

[branchburner]

he comes out the back of his stove with a 90

He may have meant a T rather than elbow... both are 90 degrees.
It's a heckuva lot easier to sweep with a T, also!

 

[prezes13]

All that made me worried again. With my flushed insert lopi cape cod I cannot or don't know where to get my temperature reading from. Anyone here has a flushed insert? If you do how do you take your readings? I posted a thread about it already and didn't really learn much. Rep from Travis Industries couldn't really help either. My dealer told me just look what is going in the box.

 

[Woody Stover]

I've got this pipe meter at one of my SIL's....bare bones. And maybe she won't freek....it doesn't say "Too Hot."

 

[rideau]

Interesting that they put the top of best operation at 475, higher than that at wasting fuel.

 

[Woody Stover]

Interesting that they put the top of best operation at 475, higher than that at wasting fuel.

That's for the pipe, not stove top...

 

[rideau]

Got it.

Thanks.

 

[HybridFyre]

All that made me worried again. With my flushed insert lopi cape cod I cannot or don't know where to get my temperature reading from. Anyone here has a flushed insert? If you do how do you take your readings? I posted a thread about it already and didn't really learn much. Rep from Travis Industries couldn't really help either. My dealer told me just look what is going in the box.

I have the fireplace xtrordinaire flush mount and have the same issues. I find that I get the most consistent reading on mine if i use an IR temp gun and shoot it right in the center of the top blower vent and aim it as far into the center of the box as I can if that makes sense. When it's running really well and nice and hot it seems to run around 400-415 degrees. But yours may be a bit different.

 

[branchburner]

My dealer told me just look what is going in the box.

And so did BrotherBart. Relax. Look at the graphic in the post directly below yours, with the "danger" zone merely indicating that you are wasting wood.

The reason I measure flue temps is to see if I need to close my bypass or adjust my air, in the name of efficiency... never in the name of safety. The only way my flue is getting "too" hot is if I left the stove wide open by accident or I'm having a chimney fire... in which case I already know the temp is way too high... frankly, I don't WANT to know exactly what temps are at that point. It's like rubbing my face in it.

If your flue runs hot, it means you may be wasting wood but are burning clean. If it runs cool, it means you could be fouling the pipe ... and THAT is your safety concern. Without seeing flue temps, you have two easy ways to address this: monitor stove top temps, making sure you are burning hot enough; visually inspect your flue periodically to ensure its clear. And the latter you should be doing even if you DO have the ability to measure flue temps.

 

[tsruggles]

After reading through all the comments I'm a bit surprised that nobody has commented on tsruggles flue set up since his wife is concerned with safety and fears a chimney fire. He says he comes out the back of his stove with a 90 and then a foot of stove pipe straight up to connect with his flex liner. It's been my experience that using a 90 elbow, rather than a T-connector in this sort of installation increases your chances of a chimney fire. With a 90 elbow any creosote that flakes off the stove pipe or flex liner falls down into the elbow where it builds up in a small pile that will eventually affect the draft if it gets big enough. It is also sitting in a spot that greatly increases the likelihood that it will catch fire if the stove starts burning too hot. With a T-connector set up any creosote that falls down the liner gathers in the bottom of the T-connector in the clean out cap where it is out the direct path of any flame or super hot exhaust gas/smoke.

I took your advice.... look at the 2.5 gallons of crap I got out. The elbow was full and I bought a brush. I thank you sir for your advice. Holy crap!

 

[tsruggles]

I now have this.

 

[tsruggles]

He may have meant a T rather than elbow... both are 90 degrees.
It's a heckuva lot easier to sweep with a T, also!

I actually used an elbow upon the suggestion of my stove dealer. Now I've got the t.