Advice on last night's runaway portal to hell raging inferno

[Caw]

Lots of good advice here. I don't really get worried about STT until it approaches 800. My stove likes to cruise between 700-750 with a nice full load of hard wood packed in on hot coals. These temps are no problem for a modern steel stove and are pretty easy to achieve with a good strong chimney. I get great secondaries, complete combustion, and good long burns. If I kept it at 600 it would stall out towards the end of off gassing and I'd end up with some charcoal from the bottom splits at the end of the cycle.

Like others have said though there's nothing wrong with being cautious about fire in your home. My first year of burning I'd have been very concerned about the secondary show and a 700 STT. Now we call that Tuesday morning around here. 🙂

 

[Wildflush]

When I spoke with PE about my situation and the runaway I had they said the stove can handle it BUT you don’t want to make a habit out of it. They said if you run hot all the time you wear your stove out quicker, such as baffles and developing potential cracks in your stove. I try to keep STT at 650 max

 

[brenndatomu]

There was a comment made about closing the air fully, and the firebox going black...the air is never fully closed on a modern stove, and a black box is the norm when running a cat stove on "low"...sounds to me like there was no real issue here, just inexperience, which goes away on its own, a little every day...
And on the MC reading, single digits are very unlikely, unless maybe its split small, and/or spent lots of time indoors in a super dry area...and those meters aren't often super accurate either...after some testing it looks like the meters that most of us use can be about 3% margin of error.
Are you testing on the middle of the fresh face after re-splitting? End grain and outside readings are worthless.

 

[Caw]

When I spoke with PE about my situation and the runaway I had they said the stove can handle it BUT you don’t want to make a habit out of it. They said if you run hot all the time you wear your stove out quicker, such as baffles and developing potential cracks in your stove. I try to keep STT at 650 max

Baffles are consumable parts. I personally don't think it's worth running the stove differently to save a year of a replaceable baffle. I'm also not too concerned about steel cracking at 700 degrees. If it were cast iron that would be another story but the only cast iron part is the door which doesn't get nearly as hot. I guess I look at it more of I'll run the stove how it runs best and if that means I get 15 years instead of 18 out of it so be it. I'm not going to make daily use more annoying to save a little time at the end. To each their own though and every stove is different so it's a little bit of a moot point.

 

[ncstar126]

Looks like I need a STT thermometer. I couldn't even tell you what my temps have been.

 

[Caw]

Looks like I need a STT thermometer. I couldn't even tell you what my temps have been.

Get a good IR fun. They aren't expensive and give real time data in multiple spots on the stove. I think it's a way better tool than a magnetic.

 

[ncstar126]

Industrial IR Gun (IR-GUN-S)

Specializing in cool, unique and professional temperature tools. Super-Fast thermocouples, thermistors, infrared thermometers, data logging and more.

www.thermoworks.com

Anything better to recommend than this? I've had bad luck with the cheap Amazon brands w.r.t. grilling/cooking.

 

[Duds13]

Industrial IR Gun (IR-GUN-S)

Specializing in cool, unique and professional temperature tools. Super-Fast thermocouples, thermistors, infrared thermometers, data logging and more.

www.thermoworks.com

Anything better to recommend than this? I've had bad luck with the cheap Amazon brands w.r.t. grilling/cooking.

I've recently bought some Thermoworks stuff, seems like good quality. I can't speak to the IR gun in your link though

 

[Wildflush]

Baffles are consumable parts. I personally don't think it's worth running the stove differently to save a year of a replaceable baffle. I'm also not too concerned about steel cracking at 700 degrees. If it were cast iron that would be another story but the only cast iron part is the door which doesn't get nearly as hot. I guess I look at it more of I'll run the stove how it runs best and if that means I get 15 years instead of 18 out of it so be it. I'm not going to make daily use more annoying to save a little time at the end. To each their own though and every stove is different so it's a little bit of a moot point.

No they were not saying specifically 700-750 but over those temps since my stove was at 750 and was continuing to rise. If i ran HOT on a regular basis wear could accelerate. personally I would like to keep my original baffle longer than spend $350. I also don’t need my stove over 650 to keep my home. Everyone has different needs just providing info that was said to me.

 

[BucksPA]

A few questions that I think relate to this discussion:
-Do you guys shut down from full open to full closed or in stages?
-What temp range do you shut down?
-Do you like to see a char on splits prior to shutting down?

We do not have a cat stove but we do have a bypass damper for secondaries.
-How does bypass damper fit in with your shutdown procedure?

 

[Wildflush]

A few questions that I think relate to this discussion:
-Do you guys shut down from full open to full closed or in stages?
-What temp range do you shut down?
-Do you like to see a char on splits prior to shutting down?

We do not have a cat stove but we do have a bypass damper for secondaries.
-How does bypass damper fit in with your shutdown procedure?

I shut down in stages. Since I don’t have a flue probe I watch the fire so I don’t use temp. Sometimes I’m wide open longer maybe 15 min but this morning I was shutting down after 7 min. Char happens in stages as I’m shutting down. I had secondaries quickly this morning with the dry wood I was using. As I shut down flue temp should come down and STT increase.

 

[neverstop]

I have a similar hearthstone stove (shelburne). I've noticed that in the early stages of the burn the secondaries on these stove occur primarily out of the tubes in the back (looks like a gas grill) and by the door. The air wash comes out above the door and that's what's providing the oxygen to burn the secondaries at that location. The visual takes awhile to get used to; initially I also had the "I'm going to burn down my house" concern.

 

[Caw]

No they were not saying specifically 700-750 but over those temps since my stove was at 750 and was continuing to rise. If i ran HOT on a regular basis wear could accelerate. personally I would like to keep my original baffle longer than spend $350. I also don’t need my stove over 650 to keep my home. Everyone has different needs just providing info that was said to me.

Yeah not doubting you. That just wasn't super clear to me when I read it originally. To me it sounded like they didn't want it running over 650 which sounded strange. You running at 650 for your house needs makes sense.

I'm shocked your baffle is $350 that is very expensive. Mine is only $150 to replace. Like we said tho every stove is different.

 

[Wildflush]

Yeah not doubting you. That just wasn't super clear to me when I read it originally. To me it sounded like they didn't want it running over 650 which sounded strange. You running at 650 for your house needs makes sense.

I'm shocked your baffle is $350 that is very expensive. Mine is only $150 to replace. Like we said tho every stove is different.

It might be less depending on the dealer. Just saw $260.

 

[Caw]

I shut down in stages. Since I don’t have a flue probe I watch the fire so I don’t use temp. Sometimes I’m wide open longer maybe 15 min but this morning I was shutting down after 7 min. Char happens in stages as I’m shutting down. I had secondaries quickly this morning with the dry wood I was using. As I shut down flue temp should come down and STT increase.

This is pretty much what I do. I just go by sound and visuals at this point. I've been using the stove for while now and can tell you what the STT is based on what I'm seeing in the box and the expansion noises the stove is making. I rarely read for the IR gun unless its getting too hot. My kids use it a lot to report the temp to me they enjoy that.

It usually takes 2-3 separate turn downs to get it where I like it to be with a good tightly packed load. I turn it down aggressively so sometimes I have to back off and give it more air then do it again. The char happens as I turn down.

 

[Wildflush]

This is pretty much what I do. I just go by sound and visuals at this point. I've been using the stove for while now and can tell you what the STT is based on what I'm seeing in the box and the expansion noises the stove is making. I rarely read for the IR gun unless its getting too hot. My kids use it a lot to report the temp to me they enjoy that.

It usually takes 2-3 separate turn downs to get it where I like it to be with a good tightly packed load. I turn it down aggressively so sometimes I have to back off and give it more air then do it again. The char happens as I turn down.

Funny what I do. I laughed at the aggressive turn down. Happens to me too than I lose secondary combustion and have to start over!

 

[elevensies]

When you see all that secondary fire happening, it means it’s a fuel rich environment. Gases and smoke are being consumed, that’s not a sign of an overfiring or leaking stove. It’s designed to pump fresh, hot air into the path of the smoke. So when you try to choke it down all a sudden, a bigger fire is the result for a time.

It sounds like I was seeing orange secondary flames mixed with the orange primary flames and just mistook it all for being primary. It makes perfect sense that choking it all the way down would make it worse in that case. Logic tends to leave the room when panic sets in.

There was a comment made about closing the air fully, and the firebox going black...the air is never fully closed on a modern stove, and a black box is the norm when running a cat stove on "low"...sounds to me like there was no real issue here, just inexperience, which goes away on its own, a little every day...
And on the MC reading, single digits are very unlikely, unless maybe its split small, and/or spent lots of time indoors in a super dry area...and those meters aren't often super accurate either...after some testing it looks like the meters that most of us use can be about 3% margin of error.
Are you testing on the middle of the fresh face after re-splitting? End grain and outside readings are worthless.

Again, good to hear this. I am testing the middle of a fresh face after splitting. I've split up some of the holly and used it as kindling since the hellfire, and it lights off like crazy, so regardless of the actual reading, it is dry and burns super vigorously. It's making sense to look at meter readings as more of a guide than an absolute. Lower number, maybe not unsafe and maybe higher moisture than the reading, but I'll be more cautious and not let everything roll for such a long time before cutting it back. As I'm learning I'll probably use anything new as kindling first just to see how it burns before I commit. If there's a 3% margin, that could go in either direction. I haven't used any more oak because no one is telling me that the black smoke is normal and I don't understand what's causing it...

 

[Caw]

Funny what I do. I laughed at the aggressive turn down. Happens to me too than I lose secondary combustion and have to start over!

Yep. That's the annoying downside to overshooting. I need to be aggressive though. My chimney is powerful and if I let the fire get too hot before turning the air down it can be hard to rein it back in. Id rather start over than be sweating an over fire and wasting BTUs.

 

[begreen]

I’ve heard that STT should not go above 600. I dont think thats possible unless with light loading and also catching your fire as early as possible. On these cold days my goal is to have it stable between 6 and 700. Highest Ive seen is 680 this year with a full firebox.

That would be true for some of Hearthstone soapstone stoves, but not for a cast iron stove. What you are shooting for on cold days is an ok temperature.

 

[elevensies]

A quick update in case it helps someone else:
We verified on another meter that the moisture reading on our oak and holly supply is indeed single digits, on a fresh split in the middle of the log. There's nothing wrong with our meter. I haven't had anything like this explosive fire happen again, and it's clear now that it was due to putting two large splits of super dry wood on hot coals. The hearthstone manual makes a point in bold letters to never put kiln-dried wood in the stove, and I'm assuming this is the reason.
We tested some more oak and didn't have a repeat of the black smoke, so it appears to have been a fluke. We split it all into kindling. Yesterday morning I started in a cold stove with a few twists of paper, three 1" pieces of mimosa kindling, and four 1" pieces of the oak kindling. It was burning so vigorously that I didn't want to open the door to put in more wood, so I let it go until it was about halfway burned. The flue temp was up to just over 400 degrees, and the catalyst was just shy of active, before I had even put the first actual log on the fire.
So, advice to other newbies: always test your wood, and never make assumptions that anything is impossible.

 

[Wildflush]

A quick update in case it helps someone else:
We verified on another meter that the moisture reading on our oak and holly supply is indeed single digits, on a fresh split in the middle of the log. There's nothing wrong with our meter. I haven't had anything like this explosive fire happen again, and it's clear now that it was due to putting two large splits of super dry wood on hot coals. The hearthstone manual makes a point in bold letters to never put kiln-dried wood in the stove, and I'm assuming this is the reason.
We tested some more oak and didn't have a repeat of the black smoke, so it appears to have been a fluke. We split it all into kindling. Yesterday morning I started in a cold stove with a few twists of paper, three 1" pieces of mimosa kindling, and four 1" pieces of the oak kindling. It was burning so vigorously that I didn't want to open the door to put in more wood, so I let it go until it was about halfway burned. The flue temp was up to just over 400 degrees, and the catalyst was just shy of active, before I had even put the first actual log on the fire.
So, advice to other newbies: always test your wood, and never make assumptions that anything is impossible.

How thick are your oak splits. Don’t think I’ve seen single digit oak. Best I have for over 3 years is 12-15%. My splits are 4-5”. Some 6”.

 

[elevensies]

The one we put on the fire was larger than all the others, so I don't remember exactly, but I would say 4" for the ones we split into kindling and 5" or 6" for the one I put in the stove. My husband has been an arborist for over a decade, and would bring home wood for the fire pit so it was never all that important to pay close attention to moisture levels or age of the splits, it was just the pile of firewood. We talked about this the other night, and he said it's entirely possible that this wood is five or six years old, because we did move a bunch of wood from our old house to this one almost four years ago. Not sure exactly how it happened, but it did!

 

[Wildflush]

The one we put on the fire was larger than all the others, so I don't remember exactly, but I would say 4" for the ones we split into kindling and 5" or 6" for the one I put in the stove. My husband has been an arborist for over a decade, and would bring home wood for the fire pit so it was never all that important to pay close attention to moisture levels or age of the splits, it was just the pile of firewood. We talked about this the other night, and he said it's entirely possible that this wood is five or six years old, because we did move a bunch of wood from our old house to this one almost four years ago. Not sure exactly how it happened, but it did!

Is your wood stacked?

 

[elevensies]

Yes, it's always been stacked up off the ground. The oak was at the bottom of the stack, not sure if that would have made a difference.

 

[Wildflush]

Usually wood at the bottom can actually have more moisture. Glad your wood is seasoned. Very dry oak has high BTU’ s and can take off. I have to watch my primary air when loaded with oak and I have a good draft going.