Stopping Overfire (Soapstone): UPDATE

[Vic99]

I'm on my 2nd season with my Homestead soapstone stove. Tonight is probably the 4th or 5th time that I've had to stop overfire (1st time this season). I use a box fan pointed at the stove from the side and it works.

Tonight its going to get to the teens so I wanted to stuff the stove. First real stuff this year.

Typically I would wait til 300F and then stuff, but since I had near miss overfires, tonight I let it get to 275 before I stuffed it. Let the wood char, open all the way for 5 minutes, closed half way for another 10. At this point temp was still around 275. Then closed to 1/4 for a few minutes and stove started to bump up. Closed all the way down.

Stove has one large white birch split and a few medium and small rounds (mostly) of what I think is sugar maple, but tough to tell as its been sitting in the river for at least 3 years without bark. Got it when we had a drought and I could walk out to it. Also threw in a few tiny pieces to fill in a few gaps. I did not stuff it REAL tight, but I tried to be effieicent.

Tonight (11:45 pm) this stove got to 580 and I put a fan on medium to stop it (overfire is 600). Got to 590 and I switched the fan to high . . . had to pick it up of the floor and aim at the top of the stove to bring it down. Have done this 3 times now as it bumps back up from 560.

I haven't used the ash pan in 10 months . . . so that is not loose. Stove door slightly fails the dollar bill test in one spot above the latch. But gasket is tight on like 90% of the door last time I checked 2 weeks ago.

Had to just get up and cool it again.

I'm glad the stove is heating up so well, but man . . . good thing I stayed up to watch it on this cold night.

I will replace the gasket this weekend unless you guys have some insight, but I'm surprised if it is just that small gasket area.

Any thoughts? Thanks

 

[Vic99]

12:15 a.m. Took fan off at 560F.

12:30 a.m. Temp dropping, but faster than I'd like. It's 510F. Better safe than sorry, but too bad couldn't make it stick at 550F for a while. Fan will stay off now and I'm going to bed. Look forward to reading ideas in the morn.

 

[struggle]

Over-drafting? mine did this and I put a dampener in the pipe and it helped greatly extend the burn times and control/slow secondary burn. My whole fire box last year would go crazy secondary burn in minutes after loading wood.

What helped though to slow it downs (Mansfield) was to rake the coals to the front of the stove and load E~W and let it burn from the front of the stove back which slows it down if that makes sense.

 

[Vic99]

I do rake coals, create a channel at the doghouse, load E/W.

I suppose it could be overdrafting. Perhaps I'll look at dampeners. I think I understand the basic concept, but don't know much about them. Since my stove vents through my internal chimney, perhaps I'd have to remove some brick?

 

[Backwoods Savage]

Vic99, I could be wrong, but aiming a fan at an over-firing stove would definitely make the thermometer reading go down, but are you doing anything with that method to cool the interior of the stove? I highly doubt it, in fact, with a fan blowing at the stove and a leak in the door, it could be counter-productive.

Hearthstone says 600 is overfiring, while Woodstock says 700. I do remember one time when we thought we might be heading towards an overfire once the temperature got close to 650. We got nervous...but nothing more happened and the temperature leveled off before it got to 700, so no overfire, just a nervous couple. What I am suggesting is that perhaps you might be jumping the gun at 580. It certainly is not overfiring at that point. Good luck.

btw, I question using that river wood. Might be okay in an outdoor fire but not so sure about in that soapstone stove.

 

[Todd]

How tall is your chimney? I does sound like it could be an over drat situation. Another option besides a pipe damper which sounds like a pita for you is to modify the air slide. If you look under the bottom left side of your stove you can see where the air slide for the primary is hooked up to control lever. I think it's just a couple allen screws to remove and you could remove the slide and grind off the stop that keeps the slide from closing all the way. This only controls the primary air, the secondary air comes in a hole in the back of the stove. If you are able to shut the primary down more it should give you more control.

I'm sure others will chastise me for the recommendation of modifying an EPA stove, but I think it's more of a safety issue if you can't control your stove with tall chimneys and maybe the EPA and manufactures didn't think of this back in the day when they were just trying to clean up the exhaust?

 

[FireWalker]

I question fuel. I'm burning thru a batch of birch right now, and it's just regular cut seasoned whits birck splitsand rounds. It burns hot and fast. Do you have any wood that is not salvaged from the rivers edge? Stuff the box with that if you do and report back.

I'm reasonably sure that when working properly with a well established fire and a good charred load, when the damper is shut down you should have a layer of floating flames just under the burn tubes and a single column of fire coming up from the wood load. Anything more than that and I expect extra combustion air is getting in somewhere.

 

[Vic99]

Backwoods

" . . . are you doing anything with that method to cool the interior of the stove?"

No, I'm only using the fan. I thought of that as an possible issue to deal with, but don't yet have a solution. I realize that woodstock's overfire temps are different. Not sure how much the configuration of the stove has to do with it and how much is just different safety policies. I figure when engineers set tolerance standards, they usually account for 5-10% error. So maybe 630 or 660 is better. That said, I do have a few hairline surface cracks, one is a bit bigger than I'd like, but it is not black, so I figure it doesn't go all the way through. Perhaps, last season the stove went over 600 F when I wasn't home over when I was sleeping more than once.

 

[Vic99]

Todd & Firewalker

My chimney is 2 stories, plus another 6 ft in the attic. Maybe 26-27 feet tall total. I've read about messing with the primary air a bit, and have been tempted, but never tried it. My experience is that the temperature goes UP when the air flow is slowed . . . except, of course, at start up.

Very little of my fuel is river salvaged. I scrounge so I take whatever I can get. These days, I'm almost 2 years ahead.

The near overfire last night looked normal. Nice burn tube turbulence, middle flames, really nice to look at, actually. Got the slight humming noise as usual when the air intake is closed as much as it can be.

 

[Jfigliuolo]

My money is on overdraft. That's a tall chimney. Is it an interior chimney? is it lined?

You may not know this... but when you THINK your dampered aall the way down... you're not, the EPA regs require the primary to still be open (quite a bit actually)

I modified my primary damper so I can COMPLETELY close it (Hearthstone phoenix). I almost always run my stove dampered past where the factory minimum would have been. I still burn very clean and hot enough.

 

[Highbeam]

That sounds like a runaway stove. 27 feet of hot masonry chimney, probably 8x8 or bigger flue, will suck very very hard when it gets ripping. Not bad until it really takes off.

The proper thing to do is to get the stove up to 550 again and take a draft reading with a meter to see if you are over the manual's limits, I think you are. Then figure out a way to fit a stovepipe damper in there between the stove collar and the chimney. If you have no way to accomplish this then I would acquire the outside air adapter for your stove and fit it with an adjustable obstruction. At the very least you can put your hand over the inlet to see if the stove gaskets are allowing air to pass.

You will typically see evidence of an air leak in the form of cresoste in weird places, a jet of flames from the leak, or by massive turbulence in the box.

You say that your stove is limited to 600 per the manual. The fact that some other manufacturer can set a higher limit for their stove is of very little value, also, the warranty for your stove is set at 600 so do respect that limit or be willing to accept full responsibility for the overfire. Remember that woodstocks are not made the same way as hearthstones, they have firebrick, a cat, etc.

I've been just past 550 on my heritage and it took a lot of effort. You are overfiring due to a problem in the stove or chimney.

 

[FireWalker]

O.K. then, what are you using to measure temps.. My Rutland stovetop thermometer looks nice and all but I think it could easily be off by 100 degrees on the high side. I tested it in the oven and the results made me want to throw it away. I use the thing to get an idea what the stove is doing; needs wood, smoldering, really cooking not so much what temp it is. So far I've had my stove right on the line where the thermometer goes to overfire and other than being too warm everything seemed fine. Actually that night I felt suprised because I would have thought my stove had more btu's to give, I still don't know because I'm not sure the thermometer is right.

Please note, if my damper is shut with a good load of wood, the stove will run between 300 and 400. If I want to get to 600 I'll have to give it more air.... like at least half throttle. Maybe you should test those door gaskets again. I read a thread here and I think it was a Hearthstone stove, on the ash door in one of the corners there was an air leak that was hard to find because the dollar bill test only checks spot locations, not all the way around.

 

[Vic99]

Chimney is internal and lined with a 6 inch insulated steel liner.

I use both a round stovetop metal thermometer and an infrared thermometer. I err on the side of caution and go with the metal, which sometimes reads 10-15 degrees higher . . . but the infrared is so much fun to play with.

I'll test the door gasket again when I get home. I should replace it soon.

I'll try putting my hand over the primary as well.

You guys are giving great advice. Thanks.

 

[Vic99]

Update:

I haven't burned in a couple of days (aye carumba) because I just replaced the door gasket and the door would not close . . . this was beyond the normal break in the gasket thing. Got a new handle from my stove shop today. Turns out that at some point the tip of my handle had broken off. Also, the handle spring had loosen up significantly and could not be tightened back. The stove shop said that this is now a known problem with some of the Hearthstone models and they modified the handle this year to solve the problem.

Stove is running at 460. Started from a cold start and filled it 3/4. Hopefully my overfire issues are solved and I'll also get back to real burn times.

Thanks for all the advice.

 

[04RevX]

Update:

I haven't burned in a couple of days (aye carumba) because I just replaced the door gasket and the door would not close . . . this was beyond the normal break in the gasket thing. Got a new handle from my stove shop today. Turns out that at some point the tip of my handle had broken off. Also, the handle spring had loosen up significantly and could not be tightened back. The stove shop said that this is now a known problem with some of the Hearthstone models and they modified the handle this year to solve the problem.

Stove is running at 460. Started from a cold start and filled it 3/4. Hopefully my overfire issues are solved and I'll also get back to real burn times.

Thanks for all the advice.

What did they charge you for the new handle? The current setup seems likes its only a matter of time before it breaks.

 

[Vic99]

My dealer surprised me. They offered me the floor model's handle and said they would just order a replacement. They suspected that it was covered under warrenty. Of course while on the phone I said that I don't want to go all the way down there, have him not be there and have another guy say that he couldn't do that.

Sure enough that is what happened. But they were able to call the guy that promised me the handle and everything worked out.

He did not charge me anything. I think the whole handle set up retails for $50, plus if they want to charge shipping (I called around to other stove places).

 

[Vic99]

No overfire on that 3/4 load of dry pine and mystery wood. Temp topped out at 485. So far so good.

 

[bcnu]

Interesting. I rarely get my Homestead above 400. perhaps 450 occassionally. I'm using poplar but put a fir cookie(maybe 4-5 inched thick and 12' across) on a going fire and got it up to 450 with that. I'd like to get to 450-500 more often. I will try keeping door open a little longer and damper open a bit longer also. I'm guilty of shutting thngs down all the way too soonh

 

[bjkjoseph]

you have to try a flue damper.its simple to install,look up florida bungalow syndrome

 

[Vic99]

bcnu:

Here's a post I put forth last time this came up:

Ok, I’ve had the homestead since Dec. I can easily achieve stove top temps above 500F most of the time. 600F is not out of the question, but obviously that is overfire territory.

In the morning from a cold start, assuming that your wood is dry (try a moisture meter)

1) Open the air intake all the way;

2) Build a top down fire (firebox should be 2/3 to 3/4 full. Use medium & small splits and kindling. Stack somewhat loosely.

Since you are having trouble, use more newspaper and cardboard than you think that you will need. Light the paper in 3-4 places, keep the door cracked for a good minute til the fire is really going;

3) Close door and keep the intake open all the way for 15-20 minutes, this will help burn off creosote in the chimney (do this every day or nearly every day once you are burning 24/7) and it will also help get the temp up;

4) Then close the intake down to 3/4 for a few minutes;

5) Go down to 1/2 for a few minutes . . . ideally stove top is above 200F. If not, wood is probably not dry enough.

6) Go to 1/4 open for a few then close all the way. Stove should really take off at this point.

Sometimes, when the stove gets to 300-350, I add another decent sized split in the middle. Char it at 1/2 for a few minutes, then close down all the way and this should put you 400+ (more likely 500+) pretty easily.

In case you approach overfire, point a fan on high toward stove. til temps come down.

Let me know how you make out. Good luck.