overfire/runaway fire...what happend?

[mikepinto65]

Just had somewhat of a close call. Had my VC Vigilant running good and steady today and after stacking some wood went down to check on her. To my surprise the thermo was reading 560 and I new something was up because it hadn't been that an hour ago and the stove should have been coming off it heating cycle. I cracked the door just to see in because the stove was in horizontal combustion and didnt want any smoke to poor in. As soon a i cracked the door, i immediately saw a runaway fire, everything in the firebox was was roaring. I ran outside to see if smoke or anything was poring out of the chimney maybe indicating a chimney fire, but it was completely normal. Than i went back in closed the air supply off and the fire kept going strong. I switched the damper open and went back outside. A good amount of smoked was released like it had been stuck (no smoke was coming inside from the stove though?). I let the fire burn with the damper open and air supply off for a few than closed off the damper and now everything is working fine. What the hell could have happened? my griddle temp went to 560ish when i went down and the black pipe was reading 380-400. I had the air shutter set to half open just to maintain good heat, was this my problem...just simply too much air? Or could I had had a problem with loosing all of my draft? I was starting to feel comfortable with the idea of running the stove when i leave my house, but now im a little reluctant again. Any opinions on this would be appreciated.
Thanks

 

[Brian VT]

Those temps sound like a normal burn to me. My griddle is usually 450-550 (per Rutland therm.) for most of the burn cycle.
I don't even start getting nervous until 650.

 

[mikepinto65]

ya its my normal burn temp too, but i never have flames during the horizontal burn that are practically jumping out when i open the door, it was a strange event....hard to put into words it just didnt seem right

 

[mikepinto65]

Also when i did open the damper, (which i previously wrote) and had a large amount of smoke pushed out, I had a small puff come from the stove into the room which has never happened...just not the amount that youd expect after seeing the amount let out of the chimney.

 

[Brian VT]

Gotcha. That does sound unusual. I don't have any ideas what was going on though.
Kinda sounds like something was superheated, waiting to go off, and the air you gave it touched it off.
I think it might have been just a weird timing thing. I wouldn't stress over it unless it keeps happening.

 

[struggle]

I had a Vigilant and it ran those temps normally after being rebuilt and it was air tight. When you closed the dampener all the way yo shut the air off and it would literally back fire from being leaned out hence your puff of smoke.

600 degree range is normal for the vigilant or at least is was on mine as that is where it liked to cruise at if the fire ox was full.

Were you burning in down draft mode? That slows the stove down a bit.

 

[Fod01]

I had the same issue with my insert last night. Was burning it all day, and had a nice coal bed when I loaded it up for the evening. Usually I use 4 or 5 big splits, but yesterday I had 1 large pine split for the back, then 4 or 5 nice sized hardwood chunks to fill it up ( over-sized splits that I cut in half). The fire caught quickly, and I was able to reduce the air fully after 5 minutes. After a short time, the fire was burning like I left the door wide open. I increased the blower speed to near max because I don't own a thermometer yet (I know, I know...) , and wanted to reduce the risk of overfire. This went on for a good hour or so until the load cooked down. Today I checked for door leaks with a punk, but didn't find any. My own thoughts are that the pine in the back was exceptionally dry, and the chunked wood allowed way too much airflow around the load. Next time I burn chunks I'll only add 1 or 2 at a time, and only on top of the load....

 

[JMF1]

I've had some barn burners goin here, I have to watch what wood I put in when I load 'er full. Some wood just seems to "gas" more than others. Maybe this is what is happening to you guys? If I load mine with dry maple only I have to stay on top of it or it'll hit 800 degrees on the stovetop easily, all secondary. I think Brother Bart posted the other day that if you wait for the stove top temp to fall to 350 or below before reloading it gives you a cushion for the new load to take off and level off without reaching dangerous temps. I've been doing that and it seems to be working well.

 

[mikepinto65]

Thanks for all the responses, I had dinner with my father and he had the same thought that seems to be coming up here....possibly super heated gases. He also said to stop analyzing my stove so much and relax! LOL thats nice to hear from an assistant fire chief! Oh well, thanks again everyone.

 

[trk2]

Hi, as a long time lurker you should know that your post finally got me to register and start contributing!

I've run a VC Vigilant for many years. In fact, I'm the only person I know who has a Vigilant with the optional "Energy Extender" cat backpack that you can mount to the back of the stove. From your description of events, I can tell you that everything appears normal from my experience of running a Vigilant. I do have a couple of suggestions that I have found give me the best performance from this stove.

First, I would never open the front or top when the stove is in horizontal burn mode. You are just asking for smoke to come pouring out. Just throw the stove into updraft, wait a second and lift the griddle to take a peek. While we're on the topic, I would resist opening the front doors in general while the stove is in the middle of a burn cycle. It is very easy for coals or logs to come rolling out and for a frantic circus act to begin.

It sounds to me like you are engaging the horizontal burn mode too early. While not as easy or as efficient as modern stoves, the Vigilant does have an early version of a secondary burner, but it takes alot of heat to get it to light off and stay going. I don't even try to switch to horizontal mode until my stove top was at a minimum of 550°, and I try to wait to 600°. When you first engage it and everything is running right you should hear a distinctive roaring sound and there should be little smoke coming from the chimney. If smoke is pouring from the chimney, you're not hot enough and you need to go back into updraft and try again. If you ignore this, and continue to run in horizontal, the stove may periodically back puff and continued operation can lead to the creosote problems that some have criticized the Vigilant for.

You'll know if you get everything working right, there will be little smoke coming out of the chimney and heat will be pouring out of the back of the stove. It will feel just as hot, if not hotter as above the griddle. If your model has a thermostat, be careful because it's location is much more sensitive to horizontal heating then updraft heating. It's happened to me many times where I have gotten my stove top temp up to 550-600, engaged horizontal mode only to come back 15 minutes later to find the thermostat has closed off all my primary air thanks to the additional heat of the secondary burner.

Anyway, I hope this helps.

 

[Brian VT]

Great 1st post trk2. Glad you came out of the closet. lol

 

[mikepinto65]

Thanks trk2, I've been doing the things you mentioned thanks to any early topic i posted. The vigilant is a great stove and really works well for an older model but what happened today was def out of the ordinary, I think I must have had a piece or two of very dry gassy wood. If i dont wait for my griddle temps to hit the 550-600 mark I get a hudge drop in temp. As for not opening the doors I very rarely do....today was just a peek because i though something was up =)

 

[trk2]

I'm glad you like your stove. The Vigilant has received more then its share of unfair criticism in terms of smoke production, but if you run it right (hot) then this is a great performing stove, is fairly efficient and should be nearly smoke free. I am naturally paranoid, and I remember the first day I got the secondary burner to light off it scared the hell out of me! Heat was just roaring out of the back of the stove. It takes some nerve (at least for me) to run a stove up to 600° with a full firebox, and then light off the secondary burner and all of a sudden have twice the heat radiating from the stove. Until I learned how the stove reacted it always felt that I was just pushing the stove into trouble.

The heat output of this stove can be overpowering when everything is working right. My one criticism is that this stove just puts out too much heat, and lots of times I find myself contemplating two choices. Either put on some shorts, mix some margarita's and run the stove efficiently, or leave the stove in updraft and be comfortable and try not to think of the wasted btu's going up the chimney.

 

[Brian VT]

Either put on some shorts, mix some margarita's and run the stove efficiently, or leave the stove in updraft and be comfortable and try not to think of the wasted btu's going up the chimney.

Sounds like an easy decision to me. :coolsmile:

 

[trk2]

Sounds like an easy decision to me. :coolsmile:

Being a yankee, an engineer and Scottish to boot, that's a lot of momentum to do things as cheaply and efficiently as possible. Jose Cuervo will regret the day I buy a more modern stove...

 

[Brian VT]

If you can roll that momentum into cheap and efficient you might could slide the Jose to the "for guests" side of the liquor cabinet and treat yourself to some Petron or similar. LOL !

 

[Horse Feathers]

Just a thought but,
When you have all the fuel burning or it may have just started to burn really well as the damper closes restricting the air flowing into the combustion area it may take some time to slow down the burn it is not so instantaneous.
When you opened the door it allowed fresh air to hit the hot gases creating a small Poof.
I had a small wood burner once that had a thermostat on the air intake and as it cooled off the intake would open slowly this fresh air would hit the hot glowing wood and gases creating a small explosion type of action along with a puff of smoke and a clang of the metal lid.

 

[mikepinto65]

I had a Vigilant and it ran those temps normally after being rebuilt and it was air tight. When you closed the dampener all the way yo shut the air off and it would literally back fire from being leaned out hence your puff of smoke.

600 degree range is normal for the vigilant or at least is was on mine as that is where it liked to cruise at if the fire ox was full.

Were you burning in down draft mode? That slows the stove down a bit.

So did you ever figure out a way to not get a "back fire?" I was just downstairs closing the damper when i decided to listen to the rumble....putting my face faurly close to the air intake. Well, the f!$#%^$ stove must have know I was peeking cause just then it had one of those back fires and puffed right in my face! It startled me at first but also gave me a good chuckle.