New to the forum, problem with Harmon Oakwood

[Jim Barry]

Hi,

We've been told this is the place to solve fireplace issues.

We purchased a Harmon Oakwood several years ago and from the get-go we have been experiencing whuffing problems. We actually did not know what was happening until it got really bad, as in, explosions that literally lifted the cast iron plate of of the stove top. I have document several youtube videos and I'll post the links here. I've had the manufacturer involved, the local dealer involved and several solutions offered, including a spinner cap to improve draft.

I've provided comments to each video and for people who have posted comments or questions to the videos, I have replied to those. Settle in with a cup of coffee. Here is our story.

[Edit: This first video will give you an overall view of the problem and a visual of the setup of the stove both indoors and outdoors. Trying to view the video text may be difficult to read for some in this forum format, myself included, so you can also view the video at YT for larger screen size.]

Dec 18 2011

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Dec 22 2011

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Dec 23 2011 (nothing too exciting here except seeing some whuffing going on in a darked room).

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Dec 23 2011

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Mar 03 2012 (0:16 shows a good example of whuffing, then watch again at 0:53)

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Mar 04 2012

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Feb 04, 2013
No video needed, as the problem continues. As I said to Joe DelaTerre this morning who commented about coming over the Hearth.com:
"No we have not yet figured out the problem. For the winter 2012/2013 the stove still whuffs. Someone said a while back we have to keep the chimney hot. (Which I already knew about.) By that, they mean the temp gauge installed in the chimney should be in the middle of the grey zone. Well, in order to do that, the damper has to be open, and the draft has to be 1/2 to full open."

That's the only way we can burn without whuffing. Problem is the stove "eats" the wood (as would be expected). I'm currently burning white/yellow birch and maple that's been seasoned for 2 years still outdoors in a covered lean-to. One of the videos shows those.

Looking forward to comments, solutions.

 

[PLAYS WITH FIRE]

Can't say what the problem is...but have some questions.

How tall, from the stove is the chimney?

Did it burn like that from day 1?

Is this a cat stove (looked on their site and says firedome)?

What are the stove temps and stack temps when this is happening?

A cap that plugged will cause this but if this happened from day 1, then draft and or low burn temps caused the plugged cap.

 

[Jags]

"More air: is basically gonna be the default answer. You have a build up of volatile gasses that are igniting and causing the mini-explosions. You either have to have the ability to burn them at a higher rate (so no build up) or the ability to move them out (more air, less efficient). Both solutions require more air. Sorry, that stove is kinda known for it.

 

[Jim Barry]

Hi PWF,

How tall, from the stove is the chimney?

20ft

Did it burn like that from day 1?

Yes

Is this a cat stove (looked on their site and says firedome)?

Not sure. It does have a secondary burn which functions very well from what I can see/hear.

What are the stove temps and stack temps when this is happening?

All over the place, from 300 to 800F

A cap that plugged will cause this but if this happened from day 1, then draft and or low burn temps caused the plugged cap.

I'll agree the standard rain cap became plugged from poor draft. The spin cap, I believe, has solved the updraft issue.

 

[Jim Barry]

"More air: is basically gonna be the default answer. You have a build up of volatile gasses that are igniting and causing the mini-explosions. You either have to have the ability to burn them at a higher rate (so no build up) or the ability to move them out (more air, less efficient). Both solutions require more air. Sorry, that stove is kinda known for it.

The stove has a dedicated 4" air intake to the outdoor that has a straight run 8ft. WETT installed as recommended by dealer, insurance and manufacturer.

 

[jeff_t]

Describe your chimney setup, top to bottom. Any elbows? That's generally a draft related issue, but that firedome system can be finicky. I think a deep, hot coal bed makes it work best.

Have you checked the moisture content of the wood? Was it packed in the shed when it was green? Just to get some of the basic questions out of the way.

 

[begreen]

Everything I see so far points to poorly seasoned wood. Beg, borrow or steal enough truly dry and seasoned wood for a week and see how the stove does. In the meantime give the fire enough air so that is doesn't start smoldering.

This doc should be helpful:

(broken link removed)

 

[Jags]

The stove has a dedicated 4" air intake to the outdoor that has a straight run 8ft. WETT installed as recommended by dealer, insurance and manufacturer.

By "more air" I was referring to the primary air adjustment.
And as BG suggests...can you confirm the moisture content of your wood?

 

[Jim Barry]

Describe your chimney setup, top to bottom.

from the stove top, 6 inch double black pipe wall runs 6ft 8in where it meets the flange that connects to the 6inch exterior pipe 2inch thick wall (see attachment). And there's 4 lengths of that pipe, each 3 feet (?) long.

That's generally a draft related issue, but that firedome system can be finicky. I think a deep, hot coal bed makes it work best.

Still whuffs with a good bed of coals.

Have you checked the moisture content of the wood? Was it packed in the shed when it was green?

No I have got checked with a digital meter. But its dry. The wood was not packed in a shed. Stored in lean-to's outdoors and covered, but yes, wood was green when put there. Initially when covered, the sun acts like a kiln in the spring and summer, you can watch the steam coming out. Very effective at drying the wood.

 

[Jim Barry]

By "more air" I was referring to the primary air adjustment.
And as BG suggests...can you confirm the moisture content of your wood?

I don't have a digital meter with numerical readout. I do have a dig meter with a red/green digital scale but I don't rely on it as it does not seem to be very accurate. I simply go by the checking on the ends and the sound of the wood when knocked. I also resaw small planks of some of the birch and maple for woodworking small projects. Wood appears dry to me.

 

[Jim Barry]

Everything I see so far points to poorly seasoned wood.

I do what everyone else round here does. Cut the trees down, chunk and split, then store covered from the rain and snow for at least a year. Then its indoors for a couple weeks before it gets burned. If there's something I'm not doing right, I sure wish someone would tell me.

 

[Jags]

Wood appears dry to me.

I don't doubt the appearance, but you would be VERY surprised at how many folks find out that their "dry" wood isn't.

 

[Jags]

I do what everyone else round here does. Cut the trees down, chunk and split, then store covered from the rain and snow for at least a year. Then its indoors for a couple weeks before it gets burned. If there's something I'm not doing right, I sure wish someone would tell me.

After enjoying this forum for several years now, I can tell you one common link amongst most users having "burning issues" with their stove - the lack of dry fuel. We have had people swear on a bible, cuss at the moon and be willing to bet their house on dry wood...only to find out that it is not.

 

[Jim Barry]

Ok, so will someone tell me (or provide a link to) the proper procedure for determining the dryness of wood? What reading equipment? Where to check (end of wood or split and read the middle)? What's the acceptable moisture reading?

 

[Jags]

http://www.harborfreight.com/catalogsearch/result?q=moisture+meeter

Take one of your splits and re-split. Test the newly exposed area with the probes aligned with the grain. You are looking for 20% (a bit higher or lower is fine).

 

[PLAYS WITH FIRE]

Sometimes when in warmer temps I will close the air down too soon and too much. I will get the, what I call. solar flares but they don't blow smoke out of the stove. This mostly happens in shoulder season cause I don't want to burn to much and get to my good stuff.

Does this happen more at the lower temps like 300 or all the time from the 300 to 800 range?

 

[begreen]

I do what everyone else round here does. Cut the trees down, chunk and split, then store covered from the rain and snow for at least a year. Then its indoors for a couple weeks before it gets burned. If there's something I'm not doing right, I sure wish someone would tell me.

It depends on the wood species. Some are ok after a year of seasoning, some are not. If this is oak, then it takes at least a couple years to season. To test the wood moisture it has to be on a freshly split, inside surface of the wood. Resplit the wood and press the meter probes into the freshly exposed face of the wood. If you lack a meter, press it up against your cheek. It will feel cool and damp if not fully seasoned.

PS: Although the wood is suspect, it is also partly the stove. Downdraft stoves can be notoriously fussy. The same wood in another stove might burn pretty well.

 

[Jim Barry]

Ok. So the moisture meter that was recommended to purchase arrived today from Harbor Freight. I split half a dozen pieces of maple, white birch, yellow birch. Pushed the pins in good, along the grain, just as recommended. Reading ranged between 14 and 18%.

Stove still whuffs. Now what?

 

[Jags]

More air.

 

[Jim Barry]

Its installed as per manufacturers instructions. And the manufacturer and dealer approved the install.

 

[PLAYS WITH FIRE]

I have to agree more air! Sometimes this happens when I shut my air down too much when I know I won't be back for a bit(jumping in shower etc). I come back and it is whuffs pretty good and sometimes enough to smoke out into the room alittle. This generally happens when I load onto a good bed of coals and close way down to quick.

 

[Jags]

Its installed as per manufacturers instructions. And the manufacturer and dealer approved the install.

The formula for fire is pretty simple. You have confirmed the quality of your fuel...Next you need oxygen. If you don't give the stove enough through its primary air setting, it is going to try and find some or go out. The woofing is caused by the lack of combustion air being met by drawing it from your chimney. It is far healthier to open the primary air a pinch. Hence - more air.

 

[Jim Barry]

The stove has a dedicated 4" line to the outdoors. We're familiar with the draft and damper issues and setups. Any combination possible you can think of; damper open, draft closed; damper closed, draft open; damper closed, draft partly open... doesn't matter. Some days it won't whuff. Most days it will.

Today I can only keep it steady burning with the damper closed and draft wide open. Outside is sustained breeze of 12-15 mph all day today. Can't keep wood in the stove it burns so quick. If I try to close the draft slowly, like from wide open to half way over the course of 15 mins, the stove cools down to about 350F. If the wind stops, within a few minutes the stove will start to smoke little bits from the draft slider area...and then poof.

 

[Jim Barry]

It is far healthier to open the primary air a pinch. Hence - more air.

Not sure what you mean by primary air. You mean the draft slider, right?

 

[Jags]

First thing I would do for testing purposes it pull that 4" OAK off of the unit and see how it reacts. See if there is any change in the burn.