Big mistake and problem with Mansfield

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NH_Wood

Minister of Fire
Dec 24, 2009
2,602
southern NH
Hi everyone,

Made my first major blunder with the stove last night. Loaded full with oak and fell asleep with the stove wide open. Woke up 5 hours later to a bed of coals. I usually set my phone alarm so this doesn't happen, but not this time.

So....I checked the stove. No apparent issues - no cracks, warping, nothing that is obvious. But, here is the problem. I reloaded the stove, wood caught, no problems until I started to back down the air. Seemed to have a tough time getting the secondaries to light and for the fire to not snuff. Finally got them to stay lit after about an hour of working with the stove. Same problem at start up this morning.

I just did another thorough inspection. The only difference I can see is at the collar. There is a larger gap between the collar and stove pipe in the back than there was before (although the collar seems perfect - no crack/warping that I can see. But, if I hold a flame to the crack, air is being sucked in. Would this possible cause such an issue with the secondary combustion? I'm going to by some high temp caulk and fill the gap to see if it helps. Any advice is certainly welcome!

Cheers!
 
I had enough draw through cracks in my stove pipe and chimney cleanout that the stove struggled when shut down to draw any air into it. If the path of least resistance in a big gap, then no need for air to be pulled into the stove. Made a huge difference on mine when I went through the effort to make everything tight.
 
That would be a good application for rutland black stove cement. It is made for this type of high heat application and will set up hard like stone and not stink like RTV.

Your draft is being spoiled by that leak.
 
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Sounds like the Mansfield took it in stride, but maybe the stove pipe did not.
Yes, a big leak here will allow the vacuum in your chimney to draw air through the leak instead of through the stove. Doh!
Furnace cement is the stuff to use.
 
I would also do a complete check of the stove pipe from top to bottom, especially if any of it is hidden behind a wall.
Maybe even pull the cap off and do a good look down the pipe to ensure it wasn't damaged.

I was having issues with my Harman, I was letting the pipe get to hot before closing it off.
This actually caused some of the Class A pipe to suffer damage, luckly since the stove started having issues (similiar to what you describe) and I had them do a check of the stove this was caught before causing a fire.

If you have some damage to your lower pipe due to the high heat, you may have damaged the pipe elsewhere.
 
Thanks guys - I really appreciate the quick responses! I bought the rutland stove cement - waiting for the stove to cool and then I'll patch up the collar/pipe gap. I'll let you all know if it fixed the problem - fingers are crossed!!

Cheers!
 
But, here is the problem. I reloaded the stove, wood caught, no problems until I started to back down the air. Seemed to have a tough time getting the secondaries to light and for the fire to not snuff. Finally got them to stay lit after about an hour of working with the stove. Same problem at start up this morning.
You might be reading too much into this due to you expecting something to be wrong after messing up. I know this well as I have forgotten or fallen a sleep on a stove many times and each time I tend to read too much into the stove operations for the first few fires after screwing up.

No stones are cracked?
No warped burn tubes?
Baffle is in good shape?
No warped cast iron parts?

If you answered no to all of those, I would chalk it up to being sensitive to your recent blunder. I don't mean that as a dig, I am just relating how I feel and react when I do the same thing.

I think the pipe warping is minor and there is a chance it is unrelated.
 
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What kind of damage did high heat do to your class A?

I was having issues with my Harman, I was letting the pipe get to hot before closing it off.
This actually caused some of the Class A pipe to suffer damage, luckly since the stove started having issues (similiar to what you describe) and I had them do a check of the stove this was caught before causing a fire.
 
It warped it. Viewing the inside of the pipe from top to bottom showed that a section of it was no longer straight.
Asked them if I had a chimney fire and was told no.
I ended up having to replace a section of my double wall duravent, and a section of the Class A.
It could be just my setup that allowed the heat to create this damage, but it is a possible concern for the OP since some of his pipe was effected by the high heat. The OP needs to take a look internally to see if there is any warping. Externally did not show any warpage.
Since the Mansfield has a different setup then my Harman, the OP may be ok, but it is something to check especially after an overfire condition.
 
It warped it. Viewing the inside of the pipe from top to bottom showed that a section of it was no longer straight.
Asked them if I had a chimney fire and was told no.
I ended up having to replace a section of my double wall duravent, and a section of the Class A.
It could be just my setup that allowed the heat to create this damage, but it is a possible concern for the OP since some of his pipe was effected by the high heat. The OP needs to take a look internally to see if there is any warping. Externally did not show any warpage.
Since the Mansfield has a different setup then my Harman, the OP may be ok, but it is something to check especially after an overfire condition.
Do you have any idea how hot it got?
 
No, but I know the magnetic temp gauge that I have on my double wall spiked a couple of times.
(Which is why I got that BBQ thermometer so I know when the Double wall is getting to hot)
This was when we have a very wet humid year and my wood was not as seasoned as I would have liked it.
 
You might be reading too much into this due to you expecting something to be wrong after messing up. I know this well as I have forgotten or fallen a sleep on a stove many times and each time I tend to read too much into the stove operations for the first few fires after screwing up.

No stones are cracked?
No warped burn tubes?
Baffle is in good shape?
No warped cast iron parts?

If you answered no to all of those, I would chalk it up to being sensitive to your recent blunder. I don't mean that as a dig, I am just relating how I feel and react when I do the same thing.

I think the pipe warping is minor and there is a chance it is unrelated.

Probably right BrowningBAR - when you make a blunder, especially a serious one ($$$$), I guess you tend to get pretty worked up! I'm really hoping for the easy fix and then I'll laugh at myself and set the damn phone every time! Cheers!
 
Probably right BrowningBAR - when you make a blunder, especially a serious one ($$$$), I guess you tend to get pretty worked up! I'm really hoping for the easy fix and then I'll laugh at myself and set the damn phone every time! Cheers!
For the next several days I kick myself and insist I have somehow depleted the efficiency of the stove and it will never be the same again. Then it passes.

But, at some point I will do it again. I woke up a few weeks ago on the couch pouring sweat. I fell asleep while waiting for the Defiant to fully catch before shutting the air down. I have no idea how hot the Defiant got, but there was no damage to the firebox, cat, or assembly. That would have been a pricy, and frustrating, repair.

This happens less and less, though. It's happened a lot less over the last three winters as my wood supply has become dry. Wet wood means longer setup time, which increase my risk of forgetting about the stove or falling asleep.
 
For the next several days I kick myself and insist I have somehow depleted the efficiency of the stove and it will never be the same again. Then it passes.

But, at some point I will do it again. I woke up a few weeks ago on the couch pouring sweat. I fell asleep while waiting for the Defiant to fully catch before shutting the air down. I have no idea how hot the Defiant got, but there was no damage to the firebox, cat, or assembly. That would have been a pricy, and frustrating, repair.

This happens less and less, though. It's happened a lot less over the last three winters as my wood supply has become dry. Wet wood means longer setup time, which increase my risk of forgetting about the stove or falling asleep.

Definitely true on the dry wood allowing for much shorter waits - just started into my first 4 year old wood, and I'll have 4 year (or more) old wood for at least the next five years at this point!
 
Hey everyone - I sealed the collar/stovepipe gap, let it dry for an hour with the heat from the last fire, and loaded the stove. Absolutely perfect - running like a champ and was able to shut down real quick. I think there might have been even a leak for the past few months (smaller) - seems to be burning even better the before the 'incident'! Thanks for the support and comments! Cheers!
 
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