PH Overfire

[Berner]

Tossed in the big night load an hour ago. Stove top temps are up to 640. I have never been this high. 675 is the start of the "overfire" range. I put a large pot of cool water on the cooktop and pointed two fans at it to cool it down. Any other suggestions?

 

[begreen]

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.

 

[Berner]

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.

Yes thermometer range was my concern. Checked it at 600 came back 10 minutes later and it was reading 640. I was concerned that it was going to continue this trend.

The fans and water have it coming back down so all is well. However now that we are on this topic if the stove does get above 700 is there anything you can do to bring it down during the burn?

 

[begreen]

You've done the right things. Keep the air set to minimum, fans on high, and ride it out. Hopefully the stove will settle down soon after the initial bloom burns off.

 

[Woody Stover]

Is there some way to block the secondary air? That should cut the legs out from under it, I'd think.

 

[weatherguy]

You didn't over fire, in this cold weather it will get about 50 degrees hotter than it has been once you shut it down so just keep that in mind when it's cold. Mine stopped at 675 last night. Prefer to keep it at 600 so I shut it down when it hits 550.

 

[Berner]

Is there some way to block the secondary air? That should cut the legs out from under it, I'd think.

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.

 

[Mainewoodchucker]

I had my stove run over 700 and still climbing a few times . Tried fans etc . The thing that worked the best for me was opening the door all the way for 5 min or so . Lets cool room air in and lets heat out . So far for me it has worked the best . Brings stove down a good bit and levels off when door gets closed.

 

[MDWOOD]

I was puckered a bit myself when my stove was nearing 700.
Mind u the house was 80 and toasty!
This super 27 is new and last night i found the "Overfire" warning sticker.
Its says when the stove or the pipe GLOWS its an overfire. Wow.

I think packing it tighter with larger splits helps.

Bill

 

[toddnic]

You did not overfire the PH! Nothing to worry about....

 

[branchburner]

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

If you put in a pipe damper, that might help in the rare event of overdraft.

650f is nothing to worry about. Even if it goes up a bit more, or even into the overfire range for a short time, there is no reason to think it would keep on going... with primary air shut, it will spike and then even out. A short or occasional temp spike that flirts with overfire is a lot different than running the stove long-term at consistently too-high temps. All is well.

If you had a downdraft stove like my Oakwood, or the older VCs and Lopi Leyden, you might have cause to worry... they were known to spike and keep on spiking... "going nuclear" was a common phrase. Overdraft can be a real problem then, causing the stove to glow.

 

[Woody Stover]

Stove top temps are up to 640.

Where was that, over the cat?

 

[Berner]

Where was that, over the cat?

Yes I have a rear exhaust so the thermometer is centered where the top exhaust would be.

 

[Sprinter]

I had my stove run over 700 and still climbing a few times . Tried fans etc . The thing that worked the best for me was opening the door all the way for 5 min or so . Lets cool room air in and lets heat out . So far for me it has worked the best . Brings stove down a good bit and levels off when door gets closed.

This makes a lot of technical sense. You're basically making it act like an open faced fireplace that way. Having said that, under the fire so to speak, it would be a gutsy thing to do. fortunately, I've never had to. I have used a fan, though, which worked for me. The other thing to watch for would be embers flying out. I would want to have a screen over the door myself.

 

[Mainewoodchucker]

This makes a lot of technical sense. You're basically making it act like an open faced fireplace that way. Having said that, under the fire so to speak, it would be a gutsy thing to do. fortunately, I've never had to. I have used a fan, though, which worked for me. The other thing to watch for would be embers flying out. I would want to have a screen over the door myself.

Wife thought I was crazy to do it but it has been the one thing that has worked the best and fastest to cool the stove down . I have only had this problem burning super dry wood and on really cold days [ 0 or below usually] .

No combustibles anywhere near my stove and have 2 feet of raised hearth in front of the stove . Never had any issues with embers . But still very careful about it .

 

[Sprinter]

Wife thought I was crazy to do it but it has been the one thing that has worked the best and fastest to cool the stove down .

This technique has been discussed a little before. I may be wrong, but you may have been the first person I've seen to have actually done it, and with success. I still hope I won't have to though...

 

[begreen]

In the past, both BB and I have opened the door to cool down the system quickly. Also more recently Dix needed a quick cool down due to a failed gasket.

 

[Sprinter]

In the past, both BB and I have opened the door to cool down the system quickly. Also more recently Dix needed a quick cool down due to a failed gasket.

Oh, interesting. I'm glad to see that it does work in practice.

 

[begreen]

It works, but it a bit unnerving.

 

[BradleyW]

I've opened the door all the way to cool a fire down a couple of times. It works. I hope I never have to do it again. I think I'm more aggressive now about shutting the air down. I would rather have to open it back up than deal with an overfire.

 

[Berner]

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 open the bypass then crank the air up high to establish good draft and minimize smoke spillage. Let it sit like this for a few minutes while I grab my wood off the porch. I set all the wood next to the stove. Then I open the door and load it as quickly as I can. If I'm slow in picking the perfect sticks for the perfect stove load my logs catch and start roaring. I have never gone past this point but I feel like if I let it stay open I would have an inferno on my hands.

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

 

[BrotherBart]

I am the one that discovered the swing the door wide open thing a few years ago when my stove was running away. As a last ditch effort at a thousand degrees and climbing.

You have to open it all the way. The acceleration you see when you just crack the door open or when you are adding wood is from putting a momentary blast of air into the load. Swinging it wide open and leaving it breaks the vacuum that is pulling air through the secondary air at the top of the firebox and sends the gases it would have been burning straight up the flue.

It is a Come To Jesus Moment for sure. But it works. You are thinking of when you have just shoved fresh splits in. Not when they have been in there awhile and are cooking off.

 

[Sprinter]

You have to open it all the way.

That would be a critical step, but probably also the scariest. You don't want a blast furnace, just a wide open fireplace.

 

[BrotherBart]

Oh the pucker factor the first time is huge. The second time, not so much. And you get a great Winter tan.

 

[Berner]

Oh the pucker factor the first time is huge. The second time, not so much. And you get a great Winter tan.

Do you open the bypass and air before opening the door?

A few years ago I opened the door when I knew I shouldn't. I woke to a few remaining embers. I put a half load in because I didn't want to put a full load on top of a couple embers. I let this cook for 15 minutes or so. I was about to engage the CAT when my schedule for the day changed. I was going to be gone for a long time and I didn't want to come home to a cold stove so I thought I should add a few more splits and fill the rest of the firebox. A little scared of opening the door with a lot of flame 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.

Learned never to rush with the stove. Though I feel like this scenario would occur similarly if the stove was on a runaway and I opened the door.