weather overfiring occurs when burning a mixed load of wet & dry wood , or high moisture content wood or unseasoned wood may depend a lot upon your particular model stove, your stack pipe and chimney combination & the amount of draft that your chimney provides & even upon the way that you laid the wood in your firebox.

While i am no expert, my stove does tend to overfire, & I have the following thoughta about it.

Normally, I would start my fire & in 10 minutes be up to 600. I would let the stove burn for about another 6 to 8 min at 600 & then set back my primary air for a 500 or 450 deg burn, depending upon how cold it was outside.

What I noticed with a mixed load of dry and partly wet, High moisture content wood was that I would hear snapping & crackling, a good indication that the wood was burning off water vapor , so i would stay with the stove until the crackiling & snapping stoped & I felt that the stove temp had stabilized & then set my primary air control for unmonitored cruising of the stove, sometimes at 400 deg,450,or 500 depending on how cold the house was.

I am in the habit of making a 10 to 15 minute safety check on the stove ,after making my “final primary air cruising” setting & i find that with dry wood,stove temps stay where I set them, no adjustment needed & i am off about my business.

But ,when burning a mixed load of dry & wet wood,I will find that stove temps are way up from what I set them for . 550 deg, 650deg.700 deg, 800 deg & one time 1000 deg when i got distracted by an incoming telephone call.

I fixed the phone call thing by buying a wireless phone, so now the phone comes down to the basement with me, so I can tend the stove properly .

What i believe is happening is that the wood is not completely dried out when i originally set the primary air & that even though the stove seems to be holding its temp for 10 or 15 minutes; as the wet wood dries out slowly,
then slowly the stack temp increases into the overfire zone, so that with wet wood, the initial air setting is higher than it would be for dry wood,in order to make the wet wood do 400 deg & as the wood dries more , there is enough air to overfire the stove, 20 or 30 minutes later.

This is especially tricky when you have been burning dry wood & get used to the stove temp staying where you set it,then run out of dry wood & have to use wetter wood from outside. You think that the stove temp is stabilized & you think that the temp will stay put & cruise nicley, only to come back on your 20 min safety check to find 900 deg stack temp & need to close down the primary setting.

POINT IS, BEWARE OF AIR SETTINGS WHEN BURNING MIXED LOADS OF WOOD , SOME WET & SOME DRY,
after the wood gets totally dry burning in the stove, your stack temps could go to overfire.

The other effect i notice is that a piece of wood,or pieces of wood will shift inside the stove, after the wood they were resting upon has burned out & crumbled, dumping unburnt fresher wood into the fire or creating a faster air flow through the stove’s firebox to the chimney.

In either case , you can might expect overfire temps on your stack mounted thermometer.

Actually, 24 gague black single wall stove pipe,the thicker of the 2 pipes sold, is rated for 1,200 deg as is my chimney, having at one time in the past supported a coal fired furnace. So, a 600-700-800- deg temp is not all
that serious, but not to be taken lightly & 1000 deg is only 200 under the pipes rating.

It should be apparent that this condition highlights the need for strigent monitoring of the stoves burning conditions.

i have been asking different manifacturers to market a high stack temp safety alarm that would activate a belt worn beeper or even just a noise alarm for the room that the stove is in & a baby monitor could be used to pick up the noise of the alarm from a remote section of the house, but they all just blow me off & ignore me.

If they can market a refrigerator alarm for $200.oo worth of groceries, why can’t they make a high temp stack alarm for a $200,000.oo house, I’d like to know.