My probe thermometer at resting state

[Split]

So, I have a lovely PE Classic LE. It tends to burn hot. I see posts on here about fluev emps and mine are always way over what others have. When I start a fire my flue gets hot fast (top down/bottom up it don't matter). In order to let my cold starts get going the thermometer generally gets up to around 1200° (I'm double wall). It then slowly goes down and stays at a solid 900° for the majority of the burn cycle and then dies down over the next few hours. My secondaries on this stove can really get going but not if I shut my stove down too early due to a high flue temp.

According to WoodHeat.org flue thermometers should not be used and that they lead to improper stove usage. Here is a quote from the site:

It turns out that there is no correct operating temperature for wood stoves because their output is modulated to provide enough heat for the conditions. So, in cold winter weather the temperature will be higher than in the fall when the heating load is lower.

"Also, each new load of wood should be fired wide open until the firebox is full of flame and the wood is charred and the edges are glowing. That will produce a high flue gas temperature. Then you might set the air control back for an extended burn, so the temperature will fall. And, as the wood load is consumed the temperature gradually falls until it is time to reload.

For most of the time a wood stove is operating, its flue gas temperature is either rising or falling. Anyone who says that you should aim for a particular flue gas temperature or even a range in temperature is setting you up for failure because steady-state burning is almost impossible to achieve.

The correspondence we see from visitors to woodheat.org convinces us that thermometers cause more confusion than clarity. People try to make their stove operation conform to the markings on the dial of a cheap thermometer or to the recommendations of someone who really doesn't know much about wood heating."

Obviously my flue Temps have me worried. Yet my stove burns well. I like what WoodHeat.org is saying and don't want to live and die by a meter. I'm wondering if my thermometer is reading correctly. It's installed by a WETT certified installer. At a resting state of room temp it does not go down to zero. It stays around 250°F. Could that mean it's off by 250°? Not a thermometer expert.

To install a new thermometer in the flue just pull this one out and stick another in the drilled hole?

I'll be going to my dealer tomorrow to discuss key dampers and other options.

Thanks for your thoughts.

 

[Todd]

Looks like your thermometer is off. Try to adjust it to room temp then reinsert and try again.

I disagree with woodheat.org. Thermometers are an essential tool for wood burning and helps you fine tune your burn.

 

[begreen]

As much respect as I have for woodheat, I fundamentally disagree with some of these statements, but that could be because they are taken out of context. I and many others run their stoves almost exclusively by the flue temps. On our stove, the stovetop temp is only consulted occasionally.

Of course flue temps will decline over time, right along with stovetop temps as the fire dies down. But letting the flue go over 1000º for a long time is a great waste of fuel and puts more stress on the stovepipe.

When burning dry wood and with the stove dialed in, our loads don't vary much in behavior. The flue temps recorded with the digital probe are consistent load after load. It's only when I don't turn down the air enough that I get a high flue temp. This thread shows how a full load behaves and how the flue temps guide the air control setting.

Starting a fire and running an EPA stove

Questions about starting a fire and avoiding a runaway stove come up so frequently I decided to document starting our stove. This is a Pacific Energy Alderlea T6 with about a 3 cu ft firebox. The stove is connected to a straight-up, 20' interior flue. The outside ambient temperature is 34ºF. The...

www.hearth.com

There are some factors that can cause high flue temps in your stove. Too strong draft, warped rails or baffle, side insulation missing or in bad condition are amongst them. The other possibility is that the thermometer is no longer accurate. Our Condar probe is old and needs replacing, but it reads low and slow. I have found that the digital thermometer is a much better tool than the mechanical probe thermometer. It reacts instantly which helps much more in seeing how air control changes affect the flue temp.

 

[stoveliker]

I agree that aiming for a constant flue temperature is often not correct. In my view the flue thermometer is a tool that tells me when I'm out of the proper (safe) operating range.
It's the (a) red signaling light for when things go wrong.

Also, aiming for as low flue temps as possible, while keeping it above the safe minimum, and while getting to the right room temperature (!), allows one to burn in the most efficient way.

 

[tdhd]

I found this thread due to the interesting suggestion of not (over)using flue thermometers. I totally get what they're saying. This morning, I had a complete panic thinking I had a chimney fire starting, because the therm has been showing higher temps the last few days. But this morning it went up around 1200 and kind of stayed around there between 900 and 1200, no matter what I did. It WAS a hot fire, and I had to point some fans at the stove to get it down below 650, if only for the sake of not wrecking the soapstone, etc. But I think I may have been more comfortable dumping more of the heat up the flue if I'd known the thermometer was broken. Once the fire was low I took it out and realized it was reading 450 at room temperature hehe.

I got the thermometer in September! Its SBI woodstove thermometer bought at Home Hardware. Useless after 4 months of use? I called the store where I bought it and he said, yeah they don't last long so theres no warranty or returns or anything. They're $40! Anyone have a better suggestion for how to at least have a good sense of flue temps without spending $40-80 every season? I have double wall so it has to be probe.

 

[TheElementalCashew]

I found this thread due to the interesting suggestion of not (over)using flue thermometers. I totally get what they're saying. This morning, I had a complete panic thinking I had a chimney fire starting, because the therm has been showing higher temps the last few days. But this morning it went up around 1200 and kind of stayed around there between 900 and 1200, no matter what I did. It WAS a hot fire, and I had to point some fans at the stove to get it down below 650, if only for the sake of not wrecking the soapstone, etc. But I think I may have been more comfortable dumping more of the heat up the flue if I'd known the thermometer was broken. Once the fire was low I took it out and realized it was reading 450 at room temperature hehe.

I got the thermometer in September! Its SBI woodstove thermometer bought at Home Hardware. Useless after 4 months of use? I called the store where I bought it and he said, yeah they don't last long so theres no warranty or returns or anything. They're $40! Anyone have a better suggestion for how to at least have a good sense of flue temps without spending $40-80 every season? I have double wall so it has to be probe.

Condar makes a good flue probe thermometer, you can find it on Amazon for $40.

 

[begreen]

I strongly recommend getting a digital probe. There is about a 1-second lag time in temperature reading as compared to the approximately 1-5 minute lag time with an analog probe. With a digital probe, you get to see the effect of changing the air control setting in almost real-time. It will change the way you burn.

 

[Eman85]

A K type thermocouple and a temperature meter like Auber sells would be the most accurate, and not much more than the mechanical probe. Condar thermometers have been accurate for me for decades cross checked against each other and with an IR gun.

 

[begreen]

Our old Condar probe drifted out of calibration over time. I recalibrated it this season with the Auber and it is still fairly accurate, but too darn slow.

 

[Newbie78]

SBI probe is $16.00 cad direct from Drolet. Home hardware is gouging.

I should check mine in some boiling water. I see high temps too.

 

[Split]

I found this thread due to the interesting suggestion of not (over)using flue thermometers. I totally get what they're saying. This morning, I had a complete panic thinking I had a chimney fire starting, because the therm has been showing higher temps the last few days. But this morning it went up around 1200 and kind of stayed around there between 900 and 1200, no matter what I did. It WAS a hot fire, and I had to point some fans at the stove to get it down below 650, if only for the sake of not wrecking the soapstone, etc. But I think I may have been more comfortable dumping more of the heat up the flue if I'd known the thermometer was broken. Once the fire was low I took it out and realized it was reading 450 at room temperature hehe.

I got the thermometer in September! Its SBI woodstove thermometer bought at Home Hardware. Useless after 4 months of use? I called the store where I bought it and he said, yeah they don't last long so theres no warranty or returns or anything. They're $40! Anyone have a better suggestion for how to at least have a good sense of flue temps without spending $40-80 every season? I have double wall so it has to be probe.

I had the same experience. My dealer who came to check my stove, when I thought my fires were too hot, stated that my sbi was 200° too high. I switched to Condar, which is visually more appealing, but is relatively the same. Perhaps 100° lower but my stove does burn hot. I'm going to be looking into a key damper in the near future. I don't like blocking the boost air hole. I feel the bottom air intake allows for a better burn as it allow the fire to burn up.

I know someone who experienced a chimney fire and they said the 'roar' was unmistakable and that they 'will never forget that sound for as long as they live'.

 

[begreen]

I had the same experience. My dealer who came to check my stove, when I thought my fires were too hot, stated that my sbi was 200° too high. I switched to Condar, which is visually more appealing, but is relatively the same. Perhaps 100° lower but my stove does burn hot. I'm going to be looking into a key damper in the near future. I don't like blocking the boost air hole. I feel the bottom air intake allows for a better burn as it allow the fire to burn up.

I know someone who experienced a chimney fire and they said the 'roar' was unmistakable and that they 'will never forget that sound for as long as they live'.

Try it with a magnet or an aluminum foil plug. It's totally reversible. For some folk, this is all they need to do. The overall burn will not be compromised.

I know someone who experienced a chimney fire and they said the 'roar' was unmistakable and that they 'will never forget that sound for as long as they live'.

It's been described as sounding like a rocket-powered freight train.

 

[Eman85]

Chimney fire is an amazing sound, especially when you have a chimney that runs straight up through the middle of a 2 story house.

 

[FPX Dude]

Yah, chimney roar, I'll never forget it, yuuou don't wanna know

 

[Woodsplitter67]

I fined the stove pipe thermometer to be useful, but not the the law of the land. I keep it there for a number of reasons. A.. it lest me know when I have enough draft to get my cat going from a cold start or if enough draft is there during a relight. It lest me know when its getting to hot when its cold outside and draft is getting to strong.. I disagree with the above that a steady temperature of the flue should be maintained, it will vary during the burn and should be monitored.

 

[MongoMongoson]

Like Begreen said, go digital if you can. The Auber solution is the one most often mentioned. I don't have an Auber but I use their thermocouple on my system.

I can see the results of adjusting my primary air control or my damper within seconds. I can even see the stove temp start to drop when I turn the range hood on high (it is over 600 cfm).

 

[xman23]

A few stove top thermometers are fine just to confirm what you see going on in the stove. Once you get the hang of it you rarely look at them.
As to the stoves heat output cycle. It will do that if you burn down all the load to coals. But when you need heat feed it, and maintain a steady heat output.

 

[begreen]

I mostly use the stovetop thermometer for cooking and making sure I have the stovetop fan in a safe temperature zone. I run the stove by the probe thermometer exclusively now.

 

[Newbie78]

I just tested my SBI probe. After removal from stovepipe it dropped to roughly 170 fairly quickly. It reads about 310-320 degrees when suspended in boiling water, so about 100 degrees high. Close enough for me.

 

[kcmclellan]

I mostly use the stovetop thermometer for cooking and making sure I have the stovetop fan in a safe temperature zone. I run the stove by the probe thermometer exclusively now.

I do the same.

 

[Eman85]

I just tested my SBI probe. After removal from stovepipe it dropped to roughly 170 fairly quickly. It reads about 310-320 degrees when suspended in boiling water, so about 100 degrees high. Close enough for me.

I guess the next question would be is it 100* high at all readings.

 

[begreen]

I just tested my SBI probe. After removal from stovepipe it dropped to roughly 170 fairly quickly. It reads about 310-320 degrees when suspended in boiling water, so about 100 degrees high. Close enough for me.

Is it adjustable? If so, set it back 100º.

 

[Newbie78]

Appears to be adjustable. Maybe at some point I'll re-test it and adjust it. However I first have to determine if the 100 degrees is a constant thru the range. Somehow? Probably in the oven with a candy thermometer as a reference. Or there may be a better way...I'd like to test it all the way up to 1000 degrees. Hmmm...might burn the paint off the dial, idk..

in any case, she got hot at a point or two. Enough to make the probe warp quite a bit, maybe 1/2 " off straight . I'd like to know what cherry red hot temp of the actual probe is? I may have hurt my pipe and even my chimney a bit, Again, idk. Yet.

 

[mar13]

I don't know the accuracy of my Condar probe thermometer. However, with many trips outside to see if the chimney is smoking, on MY thermometer the smoke disappears once the thermometer is in the 600 degree range. (Sure, I'd like it to respond quickly like a digital thermometer but this is with me taping the air slowly down to - ideally - have the temp rise at a moderate pace so the flu temp doesn't quickly race ahead.) So without knowing if it is truly 600 degrees, it's a reference point on the probe that I aim for. Also just watching the flame characteristics, as mentioned by @begreen certainly is a hrlpful additional piece of data to use.

In summary, I guess I'm suggesting to just use the thermometer as a relative value and check the chimney to find out when your stove is hot enough (and your thermometer reading at that point) for a clean burn without unnecessarily wasting heat up the chimney.

 

[Woodsplitter67]

Testing in the oven will be a hard test to do. If you set your oven tonsay 350 degrees its not actually that temperature on a steady basis.. it may get as low as 335 and as high as 375.. it may be off completely and you may not get an average of 350 degrees.. your berter off putting you magnet back on the stove and testing it with an IR gun throughout the burn cycle