overfire / steps to help control fire

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Ted69

New Member
Aug 21, 2007
38
Ok I have read some of the past postings regarding an out of control fire. I have been burning for years on an open fireplace but this year I bought a Jotul
Castine. Love the stove heats my 2000 foot house without a problem.
Last night good bed of coals stove around 500, pipe about 550.
Put a large load of dry oak, damper wide open till wood blackened, damper to almost closed. Came back in about 5min to check on fire and temp was about 750 closed damper off. Came back now at 800 pipe temp about 800. Few minutes later both still climbing. Opened the window and doors to the house to cool room and stove?
What else could I have done? Open stove door? baking soda to smother some of the fire?
I really felt out of control in this situation...Sure didnt tell my wife or she would never use the stove again. This has never happened to me before.
thanks for any info
Ted
 
Adding a damper to the pipe is a very good idea, that gives you more control.

What I do when my stove over-fires is close the air down and blow a fan on the stove to cool it, sonce it sits in a un-insulated block wall basement, it normally cools it off pretty quick.
 
I have a pipe damper on mine though I rarely use it unless the stove seems too hot but when my stove is rolling and I shut the air control all the way down and then go to the damper it does not make much of a difference it just keeps on burning. I also always have a fan blowing on the stove.
 
Ted,

Check the back of the stove on the bottom.

You probably have a large hole where the air goes in for the secondary combustion. At least that is where it is on my Jotul Oslo.

If the fire is out of control wad up a piece of tin foil and shove it in the hole. That will restrict the air to the secondary combustion and slow down the fire.

I had to do this once when I loaded my stove with a bunch of small apple pieces.

It slows the burn way down when you have the primary air control all the way closed.

J.P.

Edit: This is the best way to gain control, at least that I have found, rather than open up the door and throw something on the fire.
 
With my new Jotul, cutting the air flow all of the way down, zaps the active fire pretty quick (within 10 minutes). I don't have a flue damper with this stove, but always had one with my old steel dragon, and if I shut the damper and the air inlets, it would zap that fire quick too. The damper was particularly effective if the liner got to burning a bit (ie, flue fire) ,close that baby down and that was the end of that real quick. I dunno, almost sounds like to me that you've still got a lot of air coming into that stove and/or draft, or (this is really stretching it) almost like there was some kind of accelerant involved. Under any conditions I have yet to see my new stove temps exceed 550 or so, and that is fine with me.
 
Ted, can you describe the flue on the stove? I have a draft damper on mine, but there can be times of the right combo of wood plus heat plus strong draft where the stove can really get going. Although intense and not what you want to experience everyday, the F400 can take it. There are folks that run them at 700-750 every day. This is why a safe installation is so important. To avoid the situation, let the coal bed burn down further before adding fresh wood.

That said, a manual damper *may* help slow things down, but not always. When a large amount of fuel outgases rapidly it can release a lot of btus as it burns. In case of a true runaway, there is a way to snuff the fire. The Castine has its outside air intake in the lower back of the stove, under the heat shield. I had a near runaway when I was testing prest-logs and added too many. In that case, I partially covered the OAK intake and that immediately reduced combustion and returned control to the stove. One caveat - if you do suddenly choke off a fire, don't cut off so much air that you totally extinguish the flame. If you do, the firebox and flue may fill with dense smoke and wood gases. This becomes potentially explosive. When those gases re-ignite, it can be very dramatic.
 
This has happened to me 3-4 times this season and it always scares me- I even had a nightmare about it once. I have twice gotten as far as locating all the pets and making mental evac plans for my invalid upstairs, but my insert always peaks just before it hits 800ºF (thermometer on the door) and we make it through fine and I feel silly for freaking out. I have been assured by guys here that a door reading of 800º is not that big a deal but it is still scary to not be able to stop the thermometer from climbing.

I turn the fan on full blast and put tinfoil over the air intake, but the fire just seems to do what it wants to do. I am getting better at reading the "personality" of a fire in it's earlier stages, but am still a rank novice and hate the feeling of holding the fate of my home, family, and pets in my hands like this.

I really wish I had an emergency shut-off of some sort.
 
Thanks for all the info, I will keep in all the recommendations in mind. I will also look for the air intake hole on the back of the stove tonight.
The flue on the stove is off the top of the f400 and goes about three feet up then a 90 through the wall and up the side of the house for about 24 feet.
thanks again for the quick responses.
ted
 
This is a very informative post. I have learned a lot here and actually plan to go home and roll up some foil balls and place them behind the stove jsut in case I ever need it.
 
With a large coal bed and a big load of super dry wood you can get a run away fire. Maybe mix the wood a little put a few good dry pieces and a few junk pieces in. Next keep an eye on the thermometer, don't leave the fire unattended. Then damper it down before it's nuclear. I had the same thing happen one night and I could smell the paint in bed. The stove raged on all night, had to open a window. It was just the right combo of good wood, a big load and exceptional draft.
 

I just realized something that could be making mine hard to control. I always have a tower fan at the back corner of the stove blowing across the whole stove that could be feeding air into the secondary air supply hole???? I thought someone mentioned stoves have a hole in the back to get air for secondary combustion. The only hole in the back of my Century is for the blower.
 
hedgeburner said:

I just realized something that could be making mine hard to control. I always have a tower fan at the back corner of the stove blowing across the whole stove that could be feeding air into the secondary air supply hole???? I thought someone mentioned stoves have a hole in the back to get air for secondary combustion. The only hole in the back of my Century is for the blower.

The open hole for the secondary air on the Century's is in the back. You can't see it because it is under the heat shield.
 
In the case of a runaway hot box, I've used a fine spray water bottle to cool off the exterior. I never did this on an enamel stove - I have no idea how the enamel would react to an exterior cooling spray. I avoid a fast cool of the exterior as I can imagine causing a crack, or warping the door. But it always works with a light spray. I've dropped 800 to 600 in about 2 minutes.

Also, keep some wet wood sticks nearby, the kind that won't burn - spongy wood 2" dia from old ground drops. A few of these will slowly retard the energy in the box. Wet towels in pastic bag sounds like an interesting idea too.

Whenever I've overfired I've worried about fast heat reductions as well as runaway heating. Both can hurt the door and make the seal allow more air for the next fire, causing chronic overburn. Cooling down is critical to avoid stack/creosote fires, but I try to avoid hurting the stove when I cool it down with spray. A light hand works great to make all be safe.

Wear your glove when handling the door in case of heat blow back.

Lastly, I built a simple alarm that sounds at 650 so I can sleep without worry. Its a hack job so I could not advise on how I built it. But someone out there will see that this is a great product idea and make it happen for us all to keep safe at an affordabe price. Maybe a DIY advisory from some heat techie out there.

That's alls I know 'bout that.
 
When I rebuilt my 1970 smoking dragon 1/4 plate 12 cubic ft firebox for full secondary burn
capabilities, I included shut off valves for secondary air supply in the design.

I never though that I would ever need them , after learning the ways of my stove because the stove was always a little bit sparse on secondary air supply & so I unscrewed the valves & left them behind the stove.

After about 2 months of burning, I hit the perfect combination of just the right draft & just the right temp & just the right wood & she shot up to 1000deg stack temp on secondary burn, which I thought was unheard of & the stove top was 950 deg . Since I was standing right there, I immediately shut primary air to nothing ,stove says no response, just keeps frying. So, I close stack in line draft damper, stove say no response,just keep frying. So i open draft dump to room, stove say no response,I just keep fring . Now we heading towards 1100 stack temp & Im starting to think of where is my garden pump up sprayer but then I remember the secondary air valves that are on the floor behind the stove so I snatch one up off the floor & screw it one & shut off the valve & stove temp starts to drop 150 deg. so I run around other side of stove & grab other valve off the floor & screw it on the pipe & shut it off. Stack temp needle is beating my v8 gas gague down on its way to empty , just another minute and the stove is back to cruising at 400 stack and 650 stove top on secondary burn.

So it way the secondary air that caused or at least sustained the runaway condition & when i sut down secondary air the stove behaved nicely. Cruised great the rest of the night ,too.

I figure it was a bit too high of a primary air that got it started & then secondary air keept
it frying & i had to shut down everything primary air ,draft & secondary air to regain control.

It may have been some wet wood in the load, causing a higher than normal primary air setting to start with & when the wet wood dried out It resulted in too high of a primary air setting for the now dry wood & the stove took off. Either that or a log subsided in the firebox opening up (unblocking) a killer air passage through the wood right to the flue collar that
now required an immediate lowering of the primary air to pervent overfiring in the new conditions of the changed fire.

So even with the full arrary of controls that really do shut off right down to zero , the stove gave me a scary 4 minutes.
I have full off primary air,in line manual draft ragulator,manual draft dump to room air and full off secondary air (which again I leave the valves off the end of the secondary pipes as secondary air is a bit too little for most burning conditions.)

FULL SAFETY RECOMMENDATIONS, KEEP TIN FOIL & FLASHLIGHT NEAR STOVE in case you need to locate & plug with tin foil, either your primary or secondary air inlets. KNOW AHEAD OF TIME ,THE LOCATIONS OF BOTH PRIMARY & SECONDARY AIR INLETS .
Keep the wet towell in the plastic bag near the stove.
Keep the gargen sprayer full of water,near the stove but do not pressurize it ahead of time.
Wait until you need it to presurize it, because it only takes 60 seconds to do & when I store a garden sprayer presurized, it never works again for me & i end up buying a new one.

REMEMBER COLD WATER ON THE STOVE DOOR GLASS MEANS A SHATTERED GLASS SO
THE GARDEN SPRAYER IS THE LAST RESORT. Use the wet towell first as it wont break the glass if it dont touch the glass.

The garden sprayer can be used if the door is swung wide & clear of any water stray.

IF THE STOVE IS IN NEAR RUN AWAY CONDITION, I WOULD OPEN THE DOOR VERY VERY SLOWLY & SHIELD MY FACE & BODY BEHIND THE DOOR AS I DO SO.
Opening the door will let cooler air flood into the firebox & may help to lower temps but if cold air floods into the bottom of the firebox smoke will roll out of the top of the firebox, so if you are planning to open the stove door, open the stack damper up first & just crack the stove door to let smoke go up chimney instead of into your room. a sloowly opened stove door prevents smoke in your room.
I like the gargen sprayer because the nozzle is adjustable for a fine mist or a nasty stream of high pressure water & anything in between.

Hope my ideas help you create a plan to deal with a run away stove. It helps alot to know what to do ahead of time.
 
Eernest4 summed it up very well. First, cut the air to a minimum,not completely, or as BeGreen said when you let the air back in an explosion can happen. Think movie 'Backdraft". Also as a last resort, open the door and just give the flames a few quick spritzes of water in a fine mist. Because water expands 1700 times to form steam that will downsize the fire fast. Just don't get carried away in the moment and spray the glass or even the stove parts to cool them. If your unsure about the situation call the fire dept. immediately. Sh** happens fast with fire and incidents escalate very quickly often ending in tragedy. Be prepared, preplan your actions and don't be afraid to ask for help. Listen to you guts.
 
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