PH Overfire

[branchburner]

I feel like this scenario would occur similarly if the stove was on a runaway and I opened the door.

As long as you first open the door just a crack for a few seconds, before you swing it wide open, it'll be fine. Most stoves these days (except cats and downdrafts) don't even have a bypass damper, so that step is not as critical, but still acts to increase the draft for a moment. As soon as you open the door all the way, you kill the draft.

You can try this pretty easily without first having your stove go nuclear. Just get a good fire going with plenty of air, and bypass open, so that you are not producing too much smoke. Crack the door a few seconds, then open it wide. If the fire is well-established and your draft is good, you should have little or no smoke spill.

After a few moments you will basically have a fireplace in a box. It will burn bright, but not a raging inferno that keeps driving stove temps up and up. Some stoves have screens made for open-door burning, so you could run your stove this way (inefficiently) for hours at a time, if you liked.

I leave the door wide open quite often when I have a good bed of red-hot coals, place a few bricks and a grill in the firebox, and cook up a few steaks. Better than charcoal!

 

[branchburner]

I cut the air down and waited for a minute. Still with the bypass open I tried opening the door. A starved for oxygen fire got a taste of air as I opened the door and let out a great big poof and shot out the door.

So you already realize, the problem was you closed the air. (If you had opened it back up for just a few seconds and/or cracked the door first, no POOF.) So an important lesson, but not really related to the over-fire situation. You would simply take the same quick step as every single other time the door is going to be opened, by introducing ample air and allowing a few seconds of intensified draft to be established beforehand.

No need to fear opening the door with a raging fire (unless the splits are leaning against the door!). So there is no need to shut the air all the way first. As long as you have a good hearth out front only a popping log would pose a hazard, so a screen is essential if doing it for an extended time. Give it a try as I mentioned in my other post... seeing is believing.

 

[2fireplacesinSC]

Yeah, opened my door a few times around 850-875 degrees on my Jotul F3 last season when new to wood burning and just learning. Never glowed red hot like our BBQ fire barrel, but definitely hot enough to make me sweat with worry. So far, so good this year.

Knowing when and how much wood to add is key with an EPA tube burner.

Brother Bart's advice is correct, which I give him credit and thanks for.

Really scary (first time). Really works (every time).

 

[Sprinter]

Knowing when and how much wood to add is key with an EPA tube burner.

Agree.

 

[fire_man]

I'm not sure this makes sense to me. When I open the door to load the stove I feel like I'm playing beat the clock.

I can't imagine opening the door while the stove is in an overfire situation.

I agree w/ Berner. The Progress tends to rage even more when the door is wide open. I would hate to think I have to open the door to stop a raging stove!

One other thing with the Progress: I get PLUMES of smoke that pour out from the air intake when the door is wide open with a roaring flame. To prevent it I just make sure the air intake is closed after the door gets opened.

 

[Sprinter]

I guess maybe that goes to "not all stoves are alike" Maybe it's a cat or hybrid thing, and I have no experience with either... I still hope I don't have to do it, but I think I would if necessary. But I may buy a screen of some sort just in case. I have a fine spray water extinguisher too in case. I'm pretty sure the wet towel/newspaper thing would go a long way too, with the advantage of being able to close the door quickly.

Plumes of smoke I can identify with. It's very attention-getting. You just do what you have to do.

 

[branchburner]

The Progress tends to rage even more when the door is wide open.

For how long?

My IR gun shows the hottest place on my IS to be right above the door (700f + when stove top is around 600f). If I open the front door for five minutes or so, that temp might drop 20-30f. Of course, my flue temp spikes about 100f or more at the same time!

Opening the front door makes the roaring fire burn less efficiently (and with a cat or cat hybrid, obviously prevents the cat from burning smoke) so it makes sense that it is less hot, especially since an open door means you lose a lot more of that heat up the flue, as you would with an open fireplace.

For some reason, when we see a roaring fire in a stove with an open front door we perceive it as scary. When we see the same roaring fire in a fireplace we find it comforting. I think our fear may not be all that rational.

 

[fire_man]

For how long?

Long enough just to load the stove. The flames shoot up the open bypass but they get sucked up pretty violently and it makes quite the "roar". Nothing like a fireplace type of fire.

 

[branchburner]

Long enough just to load the stove. The flames shoot up the open bypass but they get sucked up pretty violently.

So imagine you reload and let the fire get established, and engage the cat and cut back the air. Stove temps rise while flue temps drop. If you were then to open the bypass and open the front door (after a few seconds cracked, to avoid a backpuff), the fire would indeed burn brighter, maybe even appearing to rage. But you would soon find the stove temps stop rising (and eventually fall) while the flue temps rise rapidly. The fire burns robustly, but not violently.

I think the big psychological factor is you FEEL the intense blast of heat when the door is open. Because the fire is no longer "locked up" in a box, it seems a little more threatening. But only rarely will it jump out and bite you. Once you sit in front of it for 10 or 20 minutes, you enjoy it, except for the fact you are wasting wood. Rather than bite you, it warms you to the bone. (And that's when people get complacent and assume they don't need a screen!)

 

[fire_man]

It's probably a good idea to try opening the door just to see how it behaves when fully loaded (which I have never done).

I have a hard time ever getting this stove much above 500F with my draft setup even when it's 0F outside.

 

[brushcll]

I would Imagine I can stuff some aluminum foil there to help reduce the secondary air. Didn't want to tinker with that last night with a 650 degree stove. They are calling for temps in the 50's on Sunday which sounds like a nice day to get back there.

Extra cold temps, extra high draft, more than typical stove top temps. Lesson learned.

You can use two of those magnet clips that the kids put all over the refrigerator. Some have a 1" magnet that fits over the secondary burn holes. I keep one on each front leg in case I get an over fire. I've had an over fire on my 30nc and even with the air completely closed the 4 secondary tubes will go crazy. Had the front one glow red one time. The magnets will shut their air off.

Cold weather is increasing draft. Do you mean overfire on the thermometer range? If so, I would not worry until it hits 700F. The fans are a good idea if concerned.

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