Overfired... Should I worry?

[John-Eddie]

Hi All,

I've had my Lopi Republic for a little over a year (this is the second season anyway) and I've never had too much trouble with fire temperature control, but this season it's been a little trickier - and ironically, I think it's because I have better wood that burns hotter!

So, yesterday, my morning load-up had burned down to just coals by late afternoon, and I reloaded with 4 5-6" splits, and left the vent wide open until they caught and the stove temp got back up to 350ish on top, which seems to be where it's hot enough inside for secondary combustion to work. I then closed down the vent to about 5/8 closed, as I typically do, which *usually* gets it into a slow burn with visible flame, and that doesn't smoke-up the glass door. Such settings typically get me 3 hours or so before it's just coals, and 4+ hours until I need to reload.

...OK back to the story: After choking it down I went into the kitchen to cook dinner. After about 30 minutes I went back out into the living room to help the kids with something, and smelled that "stove is kinda hot" smell. The fire was RAGING and the splits had pretty much come apart into a pile of screaming hot coals, and the area around the bypass lever was a very dull, dim, but perceptible, cherry red. IR thermometer said 925. I closed down the vent, and secondary kept the temp climbing to 940 or so before it started to calm down, and overall, it took a good 15 minutes before I got it back down in the 500's. I had also turned the blower on to try to vent the heat away more rapidly.

Everything *seems* fine, nothing looks cracked, warped, or anything like that.

Should I worry?

Thanks,

-JE

 

[jeff_t]

Sounds like you did OK. I would take a really close look for popped welds, and dollar bill the door.

I probably would have at least opened the bypass, and sent some of that excess heat up the flue. That would have helped to calm the secondary action. Opening the door wide open would be an option, too. Floods the stove with cool air and sends heat up the pipe. Sounds like a ballsy, scary move, but makes sense.

 

[Sinngetreu]

Sounds like you did OK. I would take a really close look for popped welds, and dollar bill the door.

I probably would have at least opened the bypass, and sent some of that excess heat up the flue. That would have helped to calm the secondary action. Opening the door wide open would be an option, too. Floods the stove with cool air and sends heat up the pipe. Sounds like a ballsy, scary move, but makes sense.

Yep, opening it up is a good move. It will calm things down in a hurry. That's what worked for me.
Having an overfire does help you dial in your feel for things.

 

[John-Eddie]

Thanks for the responses!

Actually, one thing *does* appear... Odd. Right now, it's running a little hotter than usual, around 650, with the vent all the way closed. There's a lot of secondary going on, but there's also a bit more primary I can see that normally wouldn't be there with the vent closed, and some secondary action arising from near the corner of the door, which I take to mean "it's leaking".

Does that sound like a reasonable assumption? Is it likely *one* overfire warped the door?!?

Thanks again,

-JE

 

[BrotherBart]

The same thing that caused the overfire is what is causing it to burn hot now. Check that door seal all the way around with the dollar bill test.

 

[John-Eddie]

The same thing that caused the overfire is what is causing it to burn hot now. Check that door seal all the way around with the dollar bill test.

Seems obvious now that you've told me that.

Forgive me for asking, but is the dollar bill test something like "shut a buck in the door, and if you can pull it out, replace the gasket"?

-JE

 

[BrotherBart]

Yep. Open the door and close it on the bill at three points each on the top, sides and bottom of the door. You should feel a little to a lot of resistance to tugging on the bill.

 

[BrotherBart]

If you find a place where the bill doesn't meet resistance, place the edge of something straight like a ruler, not a plastic one if the stove is hot, on the face of the stove body at that place. See if the front of the stove body is flat so that it makes a good seal against the gasket.

 

[loon]

Does the Lopi have a ash door on the bottom of stove John?

 

[John-Eddie]

Does the Lopi have a ash door on the bottom of stove John?

Nope - I just clean it out once or twice a week when it's cold.

-JE

 

[John-Eddie]

If you find a place where the bill doesn't meet resistance, place the edge of something straight like a ruler, not a plastic one if the stove is hot, on the face of the stove body at that place. See if the front of the stove body is flat so that it makes a good seal against the gasket.

OK, stove is still pretty hot, but I was able to do the bill test (quickly, before the bill torched)

The bill pulls out with slight resistance at every location, about equally. Far less resistance than, say, would make me worry about tearing it. About as much as shutting it in the middle of a dictionary.

Metal straigtedge across various points of the door, flashlight behind... No light leakage that I can see on a cursory examination, so if it's warped, it can't be warped too badly.

Sounds like gasket then?

Thanks,

-JE

 

[rideau]

maybe just needs the latch adjusted...

 

[BobUrban]

as long as the stove remains flat(no warpage) then a little latch adjustment should do the trick if that is an option with your stove. A little goes a long way - no need for it to be super tight - like rip the bill tight. Just snug all the way around. Sometimes just a little fluffing of the gasket will do by scruffing it a little with a piece of wood or something.

 

[John-Eddie]

as long as the stove remains flat(no warpage) then a little latch adjustment should do the trick if that is an option with your stove. A little goes a long way - no need for it to be super tight - like rip the bill tight. Just snug all the way around. Sometimes just a little fluffing of the gasket will do by scruffing it a little with a piece of wood or something.

I just tried a gasket fluff and a slight tightening of the latch. We'll see how that goes. In the meantime I ordered a new gasket, just to have on hand in case I end up needing it.

-John

 

[velvetfoot]

5/8 closed was likely not enough with the drier/different wood. You don't normally use the insert with the fan on?

 

[John-Eddie]

5/8 closed was likely not enough with the drier/different wood. You don't normally use the insert with the fan on?

Agreed - this (now 2-year old birch & ash mostly, some maple and oak) wood is *much* better than what I had last year, and I'm learning to adjust accordingly. For one thing, I can sustain good secondary combustion on lower vent settings...

As far as the fan goes, I usually turn it on first thing in the morning for a few hours, then shut it off. The past couple days, I've found I can keep the heat more even everywhere with a small fan in the coldest/farthest away room blowing towards the stove room, and with the blower on medium/low, which is probably how I'll run things from now on.

-JE