Trading Oakwood for Fireview..Crazy???

[jdonna]

Seeing what you guys think. I have had a Harman Oakwood for 3 years now. Have had issues with the stove, seems to be very draft sensitive, not to mention if you are are not around all the time, it is not a good throw wood and go stove. I have the opportunity to trade the oakwood for a woodstock fireview. You guys that run fireviews have any problems with backpuffs or issues with strong drafts and runaway fires?

One a cold day with the windblowing nothing would slow down the wood consumption and crazy heat of the oakwood, once that secondary combustion is lit there is little to stop it even with an inline damper. If you back the primary air off in this stove you can run into the rolling flames and whoosh of the secondary spilling smoke. Not a negative air pressure issues either doesnt matter if windows are open or not. 16 feet of ss liner, wind cap installed as well. Giving up the grill, top load and ash drawer but piece of mind and actual 24/7 burn would be priceless.

 

[Todd]

No problems with overdrafts or runaways here. I have had a couple back puffs because I turned it down too low. If your looking for easy set and forget long controled burns, I say go for it.

 

[jdonna]

Thanks for the quick reply. What is your chimney setup and what kind of wood do you burn? I've seen you guys post the possiblity of using 18-20" logs as well.

 

[branchburner]

Not crazy. I have an Oakwood and yes, I would trade it straight up for a Fireview of roughly the same age and condition. I understand all the points you made. I like my stove but it does have issues, and I think you are right, it is hard to get optimal draft for this type of stove. Too little draft and there's not enough pull to keep that secondary cranking, too much draft and it plows through the wood. (I just added some firebricks yesterday to see if I could improve its warm-weather performance.)

I have a strong draft, and I've thought about putting in a damper. If there was some way to control the secondary air on this stove it would make it more adaptable to a wider range of chimney and weather conditions, but I think there are so many variables that a user could spend years of trial and error and still not get the adjustments perfected.

I think the issue with the primary air is because the afterburner can't handle all the gasses early in the secondary. On the one hand, you want to cut back the air because the stove is cranking. But you need the extra air to keep the afterburner going. So you end up burning the wood hotter and faster than would be ideal.

Good luck with the switch - let us know how it works out!

 

[jdonna]

Not crazy. I have an Oakwood and yes, I would trade it straight up for a Fireview of roughly the same age and condition. I understand all the points you made. I like my stove but it does have issues, and I think you are right, it is hard to get optimal draft for this type of stove. Too little draft and there’s not enough pull to keep that secondary cranking, too much draft and it plows through the wood. (I just added some firebricks yesterday to see if I could improve its warm-weather performance.)

I have a strong draft, and I’ve thought about putting in a damper. If there was some way to control the secondary air on this stove it would make it more adaptable to a wider range of chimney and weather conditions, but I think there are so many variables that a user could spend years of trial and error and still not get the adjustments perfected.

I think the issue with the primary air is because the afterburner can’t handle all the gasses early in the secondary. On the one hand, you want to cut back the air because the stove is cranking. But you need the extra air to keep the afterburner going. So you end up burning the wood hotter and faster than would be ideal.

Good luck with the switch - let us know how it works out!

Branch Burner,

I am glad I am not the only one out there seeing this. I got caught up in the hype of long burn times, clean burning yada yada, thinking it would be different from the Vermont models.

I've talked to the dealer, chimney design people, Harman and others trying to figure this stove out.

The first year, the factory glass gasket was not right out of the box, way too loose. Replaced that.

The initial response from harman was that I was bunring to dry of wood, haha right...

I installed a windscreen on my chimney to block any down draft wind might cause, helped a little but would be hard to control even on a calm day.

Did what dill did, took the refractory out of the stove to clean, no help there either.

I have measured every point of this stove with the lowest stable secondary burn I could with a non contact thermometer, highest degree reading by the damper handle was 913 degrees. Harman engineers were surprised by this, stove was still under warranty. Not uncommon to see lots of high 700's to 800 degrees, but stove top readings are normal.

The secondary air has no adjustment you are totally right on that. If you take the shield off of it there is 6 small holes that go into the shoe brick through the bottom of the stove as well as two large holes that go into the refractory. If you smell smoke or hear a whoosh, that is where it comes from.

I have found you have to let the fist stage of secondary burn do its thing and only back off the air to a low setting after everything is in the last 3rd of the burn or you will be having whoosh sounds and mini explosions.

Interesting enough, that secondary combustion package draws air in when the damper is open, not allowing you to operate the stove as a classic type when in bypass.

Installing a pipe damper did little to help slow this stove down when the secondary cranks, if anything it actually can increase your fire dom temps, due to slowing of the gasses passing through and upsets the blance. I used the dampner in the pipe to slow down the opened bypass fires when it is warm out.

If anyone looks at their oakwood anything less than 2 1/2 notches is chocked out primary air, just left with the 3/8 pre drilled safety hole.

My verdict, is the flaw is in the lack of secondary air regulation to slow this baby down.

I'd be interested to hear if anyone really has gotten a good 12 hour burn out of this, maybe on a slower drafting chimney???

At any rate, this thing is like baby sitting a small mis behaving child.

Sorry for the oak wood fans having to read it but lets be honest here, if you are seeing some of these things please post it, there is a lot of good stoves out there but Harman has to acknowledge some issues here, they just posted some videos on their website showing how to operate it. Must have had a lot of complaints about lack of long burn times because that is the focus on their video.

 

[Todd]

Thanks for the quick reply. What is your chimney setup and what kind of wood do you burn? I've seen you guys post the possiblity of using 18-20" logs as well.

I have about 22' of chimney lined with a 5.5" flex liner. I'm burning 3 year old Oak and yes you can squeeze in a 20" split but it has to be above the door lip and be right against the door. 16-18" splits are ideal

 

[branchburner]

If you take the shield off of it there is 6 small holes that go into the shoe brick through the bottom of the stove as well as two large holes that go into the refractory. If you smell smoke or hear a whoosh, that is where it comes from.
I have found you have to let the first stage of secondary burn do its thing and only back off the air to a low setting after everything is in the last 3rd of the burn or you will be having whoosh sounds and mini explosions.

I have never had any smoke problems, only occasional whooshing, and only in the first third of the burn. I have a taller stack, so I think a better draft than you. I wonder if you had a taller stack, and then used a damper halfway into the burn to cut the draft? I guess I can find that out if I add a damper to my pipe.
First year, I stuffed some foil into the side openings where secondary air flows in - that maybe cut it back some, but it still pulls in from the seam of the shield. I have not really played around with the secondary air supply in any methodical way, but I think I will try.

Installing a pipe damper did little to help slow this stove down when the secondary cranks, if anything it actually can increase your fire dome temps, due to slowing of the gasses passing through and upsets the blance.

Sounds like the secondary air is what needs reducing here, rather than the draft. Do you see these spikes whether primary air is open or closed? If you wanted to extract more heat from the firedome, that damper might be a good thing, but sounds like it is already burning too hot. A lot like all the stories from VC Everburn-ers.

Interesting enough, that secondary combustion package draws air in when the damper is open, not allowing you to operate the stove as a classic type when in bypass.
I used the dampner in the pipe to slow down the opened bypass fires when it is warm out.

This is the most annoying thing, and why I intend to put a damper in sometime (and why I originally tried the foil). My current solution (yesterday!) was to add bricks to make the firebox smaller - too early to tell how that will work, but seemed good last night.


If anyone looks at their oakwood anything less than 2 1/2 notches is chocked out primary air, just left with the 3/8 pre drilled safety hole.

The other thing about cutting primary all the way back is that the logs in the front don't burn well, and the glass soots up. Almost always need it open a little to keep clean glass and good burning at front of the firebox.

My verdict, is the flaw is in the lack of secondary air regulation to slow this baby down.
I'd be interested to hear if anyone really has gotten a good 12 hour burn out of this, maybe on a slower drafting chimney???

I seem to get my longest burns when I have not emptied the ashes or let the coal bed burn down, so the bottom of the firebox is packed with days worth of 24/7 burning remnants. Maybe not 12 hour burns, but 8-10 no problem. Burn times seem shorter with no ashes in the pan and only a moderately deep coal bed. Not sure if this is really true, or why it would be? But I suppose in having all those coals is filling up every cubic inch of the lower firebox - I'm counting them as part of the current burn, when really they are a part of the previous burn - meaning my fresh load of wood is not truly a separate "fresh" load. Does that make sense?

 

[jdonna]

So Branch... You put foil on the rear secondary air heat shield to block the airflow to the secondary combustor??? Did you do that through the whole burning season? Interesting, Did you notice a stack temp drop and longer burn. Did you turn up your primary air a bit then after the mod to keep the firebox rolling. Believe it or not that whoosh sound you hear is actually first pushing positive pressure out the rear of the stove and then drawing air back into the combustor. Did it last night and measured with a CO meter.

 

[branchburner]

I tried with and without the foil but didn't observe a huge difference, because I think plenty of air was still getting in. I never really investigated the supply path by taking off the shield and figured if I restricted it too much I would kill the secondaries. But I may go back and revisit that.

After burning in the smaller, modified firebox today, the draft seemed excessive. I think that's because the same amount of secondary air is being pulled through, making the narrower firebox seem like a mini wind tunnel. It sure burned clean, but it burned a little fast. I'll keep playing with it.

 

[jdonna]

Running my joke-wood as we speak until I get the fireview. I have the back plate off. It seems like the air is less turbulent going in the secondary air holes, had it running while inducing smoke into it. Looking at it, if a guy was to make a 1/4" steel plate with a roped gasket recessed in the plate, a person could use the factory two holes that the shield uses to block off the secondaries and you could run it in bypass mode with full primary air control and dampen it down for these mild cold nights until you need to light off the secondary burn. The firebox is real similar to the older US Stoves, maybe add a baffle near the stack exit. I'm sure Harman would have designed a system for it if it wasn't for EPA emissions standards.

Another thing for folks to check is the bypass damper door. Seems like no matter how tight you crank down the ramp, the top of the door is never perfectly tight even with a new Harman gasket, but I do not think that would affect the burn process too much in secondary mode.

Makes sense in your firebrick experiment. Be interesting to see a down draft stove with a thick soapstone covering on the fire-dome, then you could sustain the higher temps because you would have a heat sink.

I wounder if a person could design a thermostatic gate on the secondaries as a draft controller?

I think with the varied setups, wood species, stack heights and pressure differences in each persons home it is just a down right fussy stove but has huge potential. I am guessing they designed it in a perfect lab environment. (No cross winds, perfect 16ft stack and super seasoned oak with plenty of fresh air).

 

[branchburner]

Another thing for folks to check is the bypass damper door. Seems like no matter how tight you crank down the ramp, the top of the door is never perfectly tight even with a new Harman gasket, but I do not think that would affect the burn process too much in secondary mode.

I wounder if a person could design a thermostatic gate on the secondaries as a draft controller?

I had mentioned in another thread that my damper had actually fallen open a few time until I adjusted the ramp. I think it is not a great design.

I think flue temps could be used as a guide to adjusting secondary air, if it could be made adjustable, and that would be true with bypass open or closed.

I'd love to see a stove company "bypass" the regs by providing a disclaimer such as "WARNING: DO NOT REMOVE THIS SCREW - Doing so will allow you to vary your secondary air supply to account for the varied setups, wood species, stack heights and pressure differences in each persons home. THE EPA FORBIDS THIS." I'm sure given that option some people could make the stove perform very badly, but even as it's designed now you could make it smoke like an OWB if you wanted to. Having a fixed secondary air supply is no guarantee of successful burning. That is why cat stoves are currently a superior technology, IMHO.

 

[jdonna]

That would be a good disclaimer, I agree with you on this. I have an internal flue probe and on a cold startup building a fire, I usually have to have an internal chimney temp of 900-1000 degrees to light up the secondary combustion. Makes sense because that is about what temp is needed to burn in the secondary.

Agreed, Cat stoves 500 degree temps for secondary burn, Down draft 1000+.

Refractory package 300.00 +

Cat replacement 100.00 +

They both have similar life cycles.

I think cat stoves being that you can light the cat in under 30 minutes might have a slight advantage in wood use. Down drafts you have to allow a longer charring of the wood.

What wood species does anyone burn in their oakwood??

 

[branchburner]

I burn anything and everything, but I find softwoods work great only when added as a reload on top of a hardwood coal bed. Softwoods (at least the pine, spruce and hemlock here) do not coal well enough to provide a good base for the afterburner to fire. That is one thing that would make me tell someone to not even try this stove: if you have access to only 100% softwoods, I don't see how it would work well. I'd love to know if someone has had a different experience.

I burn a lot of cherry, maple and ash, but I find the stove does best on... yes, oak. It coals up great. I'm betting hickory will, too, but it will be two years before I find out (barring any free seasoned hickory on craigslist - I can dream, can't I?).

 

[jdonna]

Update:

While trying work out a trade for the fireview.... Harman wants to send a technician out to inspect the stove and check my setup. They are finding the problems interesting. If they cannot find a problem they are supposedly willing to replace it with a new one. Even with a new stove, still thinking of going to the fireview. Might a have a brand spakin new oakwood for sale on CL for a good discount or I will install it in my garage where it is more tolerable of its nasty habits.

I am not going to hold my breath, this thing was supposed to be swapped out under warranty last year.

 

[Backwoods Savage]

jdonna, I don't know how I missed this thread earlier so sorry I did not post to it.

It might be interesting what they find out or if they find anything at all. As for the Fireview, we have a SS chimney and I don't remember for sure the height but it is below recommendation plus we live in the woods so should have poor draft. Although with our old stove we used to get lots of backpuffing, we rarely get anything with the Fireview. We've had 2 or 3 but very, very light with just the hint of smoke smell for a couple of seconds. In other words, basically you can say we don't have that problem at all. As for runaway fires, we've had a couple that got pretty hot and what we did was to have the draft fully closed and then set the bypass. In other words, turn off the catalyst. As soon as the temperature got to about 670-680 or thereabouts we were able to turn the cat back on and all was well. I might add that we were burning some very dry wood that had been split and stacked over 6 years.

All in all, we could not be happier with our Fireview. One of the very best things is that we burn only half the amount of wood we used to burn and stay a whole lot warmer. Also my wife does a good amount of cooking on it too.