Harmon Oakwood Stove Temperatures Need Help!

[jdonna]

Hey Guys,

I have been reading this site for a while and you guys know more than most retail folks. I installed an oakwood in my house 2 months ago and have noticed some odd things about it which are driving me literally nuts.

I have a 16 foot 6" chimney stainless liner in an interior masonry chimney.

After running the stove for 2 or so loads and have a good coal bed, loading the stove the flue temp can jump between 450-500 degrees when the secondary combustion has kicked in. The problem is measuring the stove top it can run 500-550 degrees.

I have the primary air set 2 notches below the mid point.


On the sides of the secondary chamber, I have measured 980 degrees with my infrared pyrometer. There is a small area that turns dull red and it will only get under control if I starve the primary completely off.

I have checked the damper adjustment, gaskets, refractory package the whole nine yards. I tried cementing the flue collar in as well, and it still gets out of hand at times.

I'm burning split dry white elm.

I called Harmon and they said it could possibly be that I have too much draft??

Anyone run into this or notice that your stove does this as well?

Any help would be greatly appreciated lol I want to go back to the non-Epa days ha.

 

[Brian VT]

Do you have room to install a stovepipe damper ? Worth a shot.

 

[BJN644]

I have a 24' interior 6" insulated chimney and I don't have any over draft problems. The Oakwood likes draft. I would double check the ash pan door. Another thing I have happen myself is on the top lid, there is a little indentation for the handle to sit, I've had small pieces of bark get in there and hold the lid up just a enough to leak.

 

[jdonna]

I tore half this bugger apart last night to double check everything. Only thing I could think of would be the leak that I fixed around the collar where the stove pipe sits, added some refractory cement. I'm sure there can be some people can relate with the lack of support with the Harman stoves at the manufacture.

Running last night with -16 below zero at two notches I was running about 850-900 degrees on the side of the secondary combustion chamber and about 600 degrees on the very back top of the stove. Chimney was sitting at 410 degrees. Top loader door was at 470 degrees.


Checked the ash door as well. I would have to agree that any stove should have good good draft to operate.

 

[R Mannino]

I have an Oakwood also, for about four seasons now. Although I have a relatively short metal chimney the stoe has never glowed red, ever, even when overfired. I have also had the ash door left "ajar" and that causes the secondary burn to take off. Something is not right, keep working at it and let us know when you figure it out.

Get the grill and cook a steak, you'll never have another stove without it.

Ron

 

[jdonna]

Nice install,

What air settings do you run and what kind of wood do you mainly burn?? I have no clue and the dealer that bought it from will not return my calls. Awesome stove but dealers and support are not happening! Thanks guys for the input.

 

[R Mannino]

I burn mainly oak, what species I'm not sure, red oak I think and some pine, tree and scrap. With the damper closed and the air wide open I can't overheat the chimney, you see where the thermometer is. I have never had to, but there is an adjustment for the latch for the secondary damper could that possibly be leaking?

Thanks for the compliment.

Ron

 

[BJN644]

It has to be sucking air from somewhere. I would light a stick of incense and go all over the stove with it burning and see if it will suck in the smoke from the incense stick indicating a leak.

Have you checked the damper gasket? it's difficult to see.

I burn mostly sugar maple with a little beech and ash in mine. After the damper is closed I run the air 3 to 4 notches from the left. Stack temp. on the magnetic thermo is 300 to 400 deg. I have checked the back before with an infared thermometer and with a good secondary burn going it's just over 500 deg.

I can get a good 10 hour plus burn running as I just described.

 

[Dill]

Check your ash pan gasket it falls off easily.
To check you damper gasket, pull off the stove pipe and feel around with the damper open. You'll feel a gasket. The other thing to check is the damper tension. There is actually a good description in the manual on how to check it. Its fairly easy to adjust the tension.

 

[Brian VT]

I tried cement on the flue collar. I ended up chipping it off and cementing in some flat rope gasket. It seems to seal much better.
I no longer have a sucking sound there.

 

[MishMouse]

On the sides of the secondary chamber, I have measured 980 degrees with my infrared pyrometer. There is a small area that turns dull red and it will only get under control if I starve the primary completely off.

Where exactly on the stove is it turning red? (A pic would be nice)
Since you have an Oakwood which is a cast iron monster a weld may have become lose in shipping/install.

1st thing I would check is to make sure all the gaskets are sealing properly.
2nd thing that might be causing it is a lose or broken piece of refractory material in the AB chamber.

The AB chamber is designed to magnify the heat multiple times to burn the smoke, 500 stove top may easily be > 1K in the AB chamber. If your sides of the stove is getting to 980 I would think there is an issue in the combustion chamber, like a crack or something allowing the heat to get to the cast iron.

Please post a pic of this next time it happens.

 

[Brian VT]

...the stoe has never glowed red

I think that he's talking about the cast iron having a reddish stain that is created by overfire

 

[jdonna]

When the stack temp is running around 400 and the afterburner is going, I measure around 780 to 840 degrees on the outside- side of the secondary combustion chamber right below the damper handle. This is running the primary air 3 or notches from the left. I have checked the damper door tension, the ash pan gasket is ok. I have checked to see if something is goofed up with the refractory package by pulling the pipe and shining a light down there as well as pulling the fire bricks out, no loose material. I am temped to pull the back part of the stove out and pull the darn refractory package out as well. I am not sure that there is any welds on the stove itself, everything seems to bolt together.

It has been more controllable since I have cemented the pipe in, but running the lower air settings has left my glass sooted up pretty bad after a longer burn to keep it from over firing.

If anyone has a infrared pyrometer check that area of your stove with the secondary combustion going. IT would be interesting to see the results.

Anyone else notice that the gasket of the glass is kind of cheap on these. I torqued the hex nuts down a little more, that could be my only guess at where un metered air could be comming in. Tomorrow night I will do the incense smoke check and post my findings.

You guys rock! Happy burning.

 

[Dill]

1 other thing and this is just guessing. If you pull the back off, where the "firedome" is. That has a simple rope gasket, mabye that is missing or there is a piece of the casting missing. Its almost a tounge and groove type of casting with a small gasket. And there is a gasket in the flue collar area correct? I'm talking about the piece you flip to make is a top vent or a rear vent.

 

[jdonna]

Dill,

Is it safe to reuse the gasket on the back panel if you pull it off or do you need to get a new gasket since it is compressed on that tounge and groove? I'm assuming that one would have to order the gasket from harman and not be able to use a universal type being that it is odd sized?

Anyone take the secondary combustion package out of them? I did notice that they seem to be sheetrock screwed together. Do they just slide out of the throat opening once you have the back panel off?

 

[Dill]

I reused my gasket when I put it back together.
You'll get different answers on how to remove the afterburner. Mine was attached to the rear stove plate and came out with it. I couldn't get it loose. Branchburner swapped his out and it stayed in the stove when he pulled off the back plate, so he was able to just reach in and pull it out seperate.

 

[R Mannino]

Dill,

Is it safe to reuse the gasket on the back panel if you pull it off or do you need to get a new gasket since it is compressed on that tounge and groove? I'm assuming that one would have to order the gasket from harman and not be able to use a universal type being that it is odd sized?

Anyone take the secondary combustion package out of them? I did notice that they seem to be sheetrock screwed together. Do they just slide out of the throat opening once you have the back panel off?

Those screws stay in, the whole chamber slides out. Look out for the two "felt" gaskets on the front of the chamber, they fall off easily. Careful, the chamber is fragile to say the least.

 

[Dill]

It is very fragile. I'd reccomend a second person to help guide it, in and out. Also have a place to set it down before you pull it out.

 

[jdonna]

Update:

I have checked it out still no solution. Here is what I have found out now.

I have tried mixing some less seasoned wood with the wood I was burning. The wood I was burning was some larger elm pieces I split not long ago, but they have been in my corn crib for a long while, not sure how long but they may have been overly dry. With mixing some tops that I cut this fall off of dead elms the stove pipe temps have been floating 350-400 with 3-4 notches of primary air.

The sides of the secondary fire dome are measuring 750-880 degrees, when it is really burning the smoke.

I did notice if you have a sustained wind that it does tend to drive the secondary package pretty hard as well. Might have to look into a wind block for the chimney cap.

Anyone want to trade some elm I had cut up probably 11 cords worth for an outdoor wood boiler which I did not buy lol. They are all cut to 24 inch lengths.

currently -11 below -38 below with a windchill, 1857 log home inside temp 75 degrees. Heat source harman oakwood.. beautiful even with the frustrations with this stove.

Thanks for your help guys I will keep posting what I find.