Overfired last night

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

therealdbeau

Burning Hunk
Oct 16, 2018
163
VA
So I'm pretty sure I overfired my insert (VC Merrimack) last night and am looking for some solace.

m8OaBYad2cUf2HeRTCoNHyeM86I7pF7eCa3HTCYYj2ZPRBciQpPi_lzKKAEQTSXRiWGw3yLb1yxB716gBo4rCw0A0g=w2400.jpg

Before bed I threw a few packs of "bio-bricks" in the stove for the night burn and turned the air all the way down. Well things really got going and appeared as if I had summoned a direct portal to hell. I wasn't all that concerned at first, I've had my stove roaring pretty good before but when I shut the lights and leaned in to take a picture of the hell-fire I noticed an ever so slight glow from behind the top grate.

The area that appeared to be glowing ever so slightly was the the flue connector area. It's hard to get my IR gun to read in that area because there isn't a clear shot to it but the thermo caught a glimps of something in the 900's. The front glass are of the stove was in the 700's I think.

It was 15 degrees F outside so I opened the two doors in that room to the outside thinking the blower would draw in the cold air and help cool things off. After maybe 20 minutes the glow faded out and eventually the fired died down enough I felt comfortable going to bed.

Will she be okay?
 
Last edited by a moderator:
Pull the insert? I don't think so. I'm not sure I'd be overly concerned about the one rare slight glow near the flue connector. Not insert-pulling concerned, anyway. :)
 
If you can allow the stove to go cold, stick your head in there and give it a look. Look for anything warped or damaged. That includes the baffle material. If all seems as it should I would chalk it up as a learning experience. I doubt that you damaged anything but it does warrant a good look over.
 
Pull the insert? I don't think so. I'm not sure I'd be overly concerned about the one rare slight glow near the flue connector. Not insert-pulling concerned, anyway. :)


I was thinking about the VC reputation. A regular steel stove, no issues.
 
Thank you all for the replies. The stove is mostly cast iron and I'm reading that possibly that makes it more resistant to issues caused by over-firing as opposed to steel. Is this true?

I only left a small fire in there when I left today so by the time I get home it should be cool enough that I can look around inside for any issues. What am I looking for? Warped secondary tubes and baffle? Cracked bricks? I think that's about all I'll be able to see without taking it apart.
 
You prob did overfire and should inspect but unlikely you did any permanent damage.

If you ever find yourself in that postion again open the door fully. All the room air you will take in and exhaust will cool it. Sounds counterintuitive I know.
 
  • Like
Reactions: Blaze19XX
One overfire probably did not do permanent damage. BioBricks pack a lot of heat, use just one or two to help a fire along or use a wall of them as directed in the instructions.

http://originalbiobricks.com/howtoburn
 
Last edited:
A couple thoughts:

I've got a VC Montpelier insert and right above the baffle is a u shaped piece of cast iron that sticks down from the stove top and acts as a deflector and pushes the air to the sides to increase retention time. Anyhow, I had that glowing the other day, it was just getting hit by a direct and constant stream of secondaries...but my glow was intermittent and almost behaved like a spark, it would sort of momentarily flare red and then go back to black. I realized after the burn it was some creosote that was on the deflector that was glowing/flaring intermittently, not an overfire in my case. Just putting that out there in case your situation was the same.

Regarding the portal to hell, I had some extremely dry pine. In fact all I have is pine but some of it was at like 12%. I just got my insert this year and of course went and grabbed the driest wood to start with. Had a couple probable overfires... couldn't even stay to check as the paint fumes ran us out of the house (wasn't going to chance it with my 1 year old). Insert is fine though, liner got a bit discolored (kind of a bronzed color) just above the insert but that's normal even without overfires. So, hopefully that provides some solace.

These VC inserts are pretty tough. I think the full cast body does help in these situations.
 
The fire in my stove looks like that on nearly every hot reload as I incrementally close the air down to it's cruising position. I've never seeing anything external glowing though.
 
Your pic definitely looks overfire-ish. But like others have said probably ok, but worth the checking out that was recommended.
 
So after that night I took the baffle out and looked around. Attached some pics.

So I'm at it again tonight except without a stove full of bio bricks. Just 2-3 along with a full load of logs. I turn the lights out and sure enough as I peer through the top grate I see a faint glow. I'm thinking "what gives". The fire isn't raging out of control just exceptional secondaries which seems typical.

So I start experimenting with ways to cool things down. I start by opening the doors all the way like I've seen suggested. After a few minutes it doesn't appear to be helping, still the glow persists. I move on the plan B and go out and grab a large green split and cram it in the stove and turn the blower to high. Only now do I see the glow fade.

This whole time I'm reading the front glass area at around 650-700. There really isn't a practical place other than that to read temps on this stove. If I'm lucky and aim just right through the top grate I can catch a glimpse of the top of the stove flue connector area of which I saw a quick reading of 970 but at that point the thermometer is inches away from the stove so I don't know if that is throwing off the numbers because of the radiant heat. However metal starts to glow around 950 or so right so I guess maybe it is accurate.

Its beginning to seem like I can't fill this stove for say an overnight burn without overfiring.
 

Attachments

  • IMG_20190202_174507.jpg
    IMG_20190202_174507.jpg
    132.9 KB · Views: 340
  • IMG_20190202_174525.jpg
    IMG_20190202_174525.jpg
    131.2 KB · Views: 352
  • IMG_20190202_174251.jpg
    IMG_20190202_174251.jpg
    220 KB · Views: 350
  • IMG_20190202_174302.jpg
    IMG_20190202_174302.jpg
    198.3 KB · Views: 362
  • IMG_20190202_174256.jpg
    IMG_20190202_174256.jpg
    265.4 KB · Views: 380
  • IMG_20190202_174354.jpg
    IMG_20190202_174354.jpg
    113.7 KB · Views: 300
Not a pro, but I would guess that an air leak could be the problem, whether a gasket or elsewhere. Temps is in the 900’s is way too high to be normal.
 
“ I summoned a direct portal to hell.”

How many bricks did you put in there?!

That’s what I thought when I put two bio blocks in my tiny stove.

How are they working in your tiny stove? I feel like they might be the best fuel for those boat stoves.
 
How are they working in your tiny stove? I feel like they might be the best fuel for those boat stoves.

I’m impressed with how well they work. Burns hot for 2-3 hours. Very little ash or coals; which makes sense considering it’s compressed dust. Two bio blocks fit side by side perfectly.
I just wish I could get them more locally. I asked the mom and pop hardware store down the road to look into them. I’m saving what I have left for another deep freeze.
I found bundles of kiln dried white birch at the grocery that fit my stove (cut to 12”) I split them down a bit more and use it with my not so seasoned oak. Burns great, smells good, but good lord, the coals.
 
  • Like
Reactions: SpaceBus
So after that night I took the baffle out and looked around. Attached some pics.

So I'm at it again tonight except without a stove full of bio bricks. Just 2-3 along with a full load of logs. I turn the lights out and sure enough as I peer through the top grate I see a faint glow. I'm thinking "what gives". The fire isn't raging out of control just exceptional secondaries which seems typical.

So I start experimenting with ways to cool things down. I start by opening the doors all the way like I've seen suggested. After a few minutes it doesn't appear to be helping, still the glow persists. I move on the plan B and go out and grab a large green split and cram it in the stove and turn the blower to high. Only now do I see the glow fade.

This whole time I'm reading the front glass area at around 650-700. There really isn't a practical place other than that to read temps on this stove. If I'm lucky and aim just right through the top grate I can catch a glimpse of the top of the stove flue connector area of which I saw a quick reading of 970 but at that point the thermometer is inches away from the stove so I don't know if that is throwing off the numbers because of the radiant heat. However metal starts to glow around 950 or so right so I guess maybe it is accurate.

Its beginning to seem like I can't fill this stove for say an overnight burn without overfiring.

Is there no baffle?
 
Ok, baffle removed for pics. Got it.

The baffle was put back in place before burning again? Just checking.

I wouldn't worry at all about the baffle glowing. But the flue should not be.

Have you tried shutting the air down sooner after reloading? I was making the mistake of leaving the air open too long, and it made it hard to control. Now we just apply the brakes much sooner, and don't have glowing flue issues anymore.
 
  • Like
Reactions: Don.S
i ended up partially blocking my air tubes with steel foil (dont use aluminum, it will melt) to keep my Monty under control. they were just drawing in too much air which mafe it impossible to dial the fire down as far as it should be.

i only have 15 feet of pipe but it terminates right above a line of tall shrubs so i think there is a lift effect at play. also my pipe is about 7 feet higher than the peak of the house so it should have even greater stack effect. drafts great and with the tube mod burns great.

how tall is your chimney?
 
Is that some kind of adjustable elbow going from the stove to the liner? It looks like it might be coming apart..? I would get rid of that and go to a rigid welded-seam 15* or 30* elbow if possible.
 
Ok, baffle removed for pics. Got it.

The baffle was put back in place before burning again? Just checking.

I wouldn't worry at all about the baffle glowing. But the flue should not be.

Have you tried shutting the air down sooner after reloading? I was making the mistake of leaving the air open too long, and it made it hard to control. Now we just apply the brakes much sooner, and don't have glowing flue issues anymore.

After reloading in this case I just left the air closed all the way. It wasn't necessary to open the air to get it going.

i ended up partially blocking my air tubes with steel foil (dont use aluminum, it will melt) to keep my Monty under control. they were just drawing in too much air which mafe it impossible to dial the fire down as far as it should be.

i only have 15 feet of pipe but it terminates right above a line of tall shrubs so i think there is a lift effect at play. also my pipe is about 7 feet higher than the peak of the house so it should have even greater stack effect. drafts great and with the tube mod burns great.

how tall is your chimney?

Chimney is around 17 feet. Just above the minimum requirement per the manual. I've seen you mention that you partially blocked your secondaries and it really might be necessary. The secondaries on this stove really take off. It's like 100 mini blow torches all scorching at once. I wish there was a damper to regulate the secondaries.

Is that some kind of adjustable elbow going from the stove to the liner? It looks like it might be coming apart..? I would get rid of that and go to a rigid welded-seam 15* or 30* elbow if possible.

I'm not entirely sure what kind of elbow is there connecting the liner to the insert but I didn't notice anything wrong with it. It didn't appear to me to be coming apart in any way. I had a licensed chimney company install the insert and while I wouldn't say they were the most meticulous bunch they got the job done. I plan on pulling the insert out this spring and giving a good look around and cleaning up the install where I see necessary.
 
After reloading in this case I just left the air closed all the way. It wasn't necessary to open the air to get it going.



Chimney is around 17 feet. Just above the minimum requirement per the manual. I've seen you mention that you partially blocked your secondaries and it really might be necessary. The secondaries on this stove really take off. It's like 100 mini blow torches all scorching at once. I wish there was a damper to regulate the secondaries.



I'm not entirely sure what kind of elbow is there connecting the liner to the insert but I didn't notice anything wrong with it. It didn't appear to me to be coming apart in any way. I had a licensed chimney company install the insert and while I wouldn't say they were the most meticulous bunch they got the job done. I plan on pulling the insert out this spring and giving a good look around and cleaning up the install where I see necessary.
If I couldn't cut the air off enough to kill the fire on a reload, I'd figure out how to block the air inlets. Once you find the inlets, you might be able to experiment with partial blockage until you get where you want to be.
 
The first thing that will get damaged IMO would be the secondary tubes. They will bow down in the center. Doesnt look like they were affected. I dont see any damage but I am not an authority on the subject. At least your flue is clean now!