New Jotul 3cb in our new home

[Englishteacher]

We recently moved from a boxy, yet cozy cape cod to a newer, renovated two story cottage with an open floor plan and a two-story cathedral ceiling in a main foyer. The old home had a circa 1992 small Century steel wood stove that was simple and served us well, though try as we might we could never get the heat out beyond the one room it was in. It had a simple baffle and was lined with firebrick. For the new home we decided to get the Jotul 3cb mostly because of its nice aesthetic, as it sits in that foyer in the middle of the house for all to see. Also, many a salesman told us it was a classic for both quality and value. The stove pipe is double walled and goes 20 feet straight up to the ceiling. We have a ceiling fan up there to help keep things moving. I'm enjoying breaking this new stove in especially seeing that the heat from the stove actually circulates throughout the house with a pretty good, even balance, and that's about 1900 square feet, as opposed to our old house where the wood stove room was 80 and the rest of the house 60.

I've got several questions though if someone can help me out. The tall, straight, chimney run provides a very strong draft but blows through wood at a very quick rate. It rarely smolders and burns everything down to mere ashes. is there any way to slow down the air flow beyond the usual damper controls. or should I just be grateful I've got a chimney with a good, strong draft? Also, the quest for fire in the secondary burn chamber eludes me. Can I expect to see actual flames shoot out of those holes in the baffle at any point or is that all merely for show? I haven't been able to see anything resembling a secondary burn yet. Also I'm using old firewood until I can get a fresh cord. At what point does seasoned firewood lose its potency if left unused? Finally, What about those "eco-fans" I've seen. Are they for real or are they more gadgetry than function? Our primary heat in this new home is heat pump and thus far has been as disappointing as others who have one told us it would be for heat. So we hope to be able to use our new wood stove in a functional, efficient as well as pleasant way. Looking forward to the sage, edifying, and wide-ranging advice I've seen on this site. Many thanks.

 

[jpl1nh]

Absolutely add the pipe damper. It's simple and effective. Old wood does not loose its potency unless your a human male or your firewood is exposed to moisture. I've never burned a secondary air system personally so I'm not that knowledgeable on that issue but it might be that your draft is so strong that your venting much of the gasses before they have a chance to combust, hence the pipe damper might change that. You must certainly be running hot enough for a secondary burn. Congrats on the upgrade. Glad your happy with it. Any pics?

 

[begreen]

We had a stack damper on the F3CB with a 16 ft flue and it worked well. We also have the ecofan and it is quiet and handy for circulation, though it sounds like you have this covered with the ceiling fan. (The ecofan does work in a power outage which can be frequent in our area. I woke up to one this morning.)

You should see good secondary burning with the F3. Do you have a stove top temperature gauge? If so what is it reading? You should see secondary burning after about 10-15 minutes of burning, especially if you reduce the air to about 50% (and be sure the start up air control is closed).

 

[Englishteacher]

Thanks for the feedback. Most helpful. Re the secondary burn: I try to keep the stovetop thermometer between 400 and 600 degrees. Usually that has the damper between half open and full. Would I know a secondary burn if I saw it? I've looked at the photo gallery here and the pics of secondary burn look like they'd be pretty noticable. Does it have a distinctive color or intensity to the flame etc. What I do see is flames from the wood licking the baffle and maybe igniting but I think I'm just trying to convince myself of that. What conditions are optimum for secondary burn? I might just be burning the stove ineffectively for the secondary burn to occur.

 

[wahoowad]

Hello and welcome Englishteacher!

Yes, secondary burn is a very visible thing of beauty that you can watch with this stove (I have one). Once you see it you will know! Those little holes you can see on the top inside of your firebox will supply heated oxygen to ignite and burn gases given off by the burning of the below wood. You'll see, in essence, jets of flame.

I usually see it in my stove about 20 minutes after refilling it full of wood on top of coals. First I let the new wood char on full air (primary air wide open) for 10 to 15 minutes. Then I slide the air control about 35% closed and let it burn another 10 minutes or so. Adjust again another 30% closed, let it burn a few minutes, then clide it all the way closed. Usually the secondary burn really kicks in when I slide it closed on this last step. I'll get secondary burn for about 1.5 hours until the logs have given up what they can to gasification. I then get some heat out those coals for 30 to 45 minutes, then time to reload. I get anywhere from 2 to 3.5 hours per load depending on type of wood and how well I manage the air supply.

Your stated temps sound good. You should spend most of your burn cycle with your primary air closed. The stove is designed to still provide enough air to support a clean burn evenwhen you have it "closed." Try gradually decreasing your air like I suggested and see if that secondary burn doesn't appear.

Also, tell us a bit more about this "old wood" you say you have. Where did it come from, how long have you had it, has it been covered, when was it split, etc. How big are the splits and what type of wood is it. A lot of people thin they have good wood when in fact they have marginal wood.

I'm just repeating stuff I learned here. BeGreen and others have been very helpful to me.

 

[Englishteacher]

Thanks for the info re secondary burning. I've tried various strategies, no luck yet in achieving same. I do see, though, a broader, lusher, semi-transparent, gaseous looking flame in the box sometimes that I've read is an indicator of secondary combustion. That seems to occur only at higher temps and more air. Nothing resembling flame coming out of those little jets. Not to put too fine a point on it, but sometimes with flames from the box going up toward the jets the flames actually seem to separate around the jet hole only to close up again above it, but even that is infrequent. The stove is top-vented as opposed to rear or side if that could mean anything. The chimney "smoke" is a nice clear heated blur. Beats me. But I will not give up the quest.
Re old wood. It was stuff I had lying around the yard from various years from the bottom of various woodpiles; it's hard to determine the age, anywhere from two to five years. My wood guy arrived yesterday with a nice, fresh seasoned cord, I got it stacked neatly in the yard, it's burning well, the house is warm and all's right with the world--except that elusive secondary burn thing.

 

[begreen]

Secondary burn will happen when the firebox is hot and wood is outgassing. If you can look at your chimney top about 10 minutes after adding a fresh load of wood and see no smoke, the stove is burning correctly. FWIW, you can burn the stove a bit hotter. We ran ours at 550-650 degrees which usually guaranteed a nice light show for about 30 minutes after the air was closed down.

There is some variety in secondary flames depending on the wood. Some outgas mightily as the wood is heated, some more slowly. Sometimes there will be a powerful set of streams coming in front of the secondary ports and at other times it is almost wraithlike. This is the secondary combustion of gaseous fumes coming off the wood. Once they have burned off, the light show is over. Often one won't see them with the first load of wood, but you should see them with a reload over hot coals once the stove air control is closed off a bit.

With the strong draft on your stove you might try closing off the air control a bit more. If the fire is getting too much primary air, then there may be little visible secondary combustion. Try closing the air control down to 3/4's cllosed or maybe even all the way about 5-10 minutes after a fresh load of wood has been added to the stove. The fire should die down, but not go out. Then there should be transparent bluish flames that waft and dance almost ghostlike, over the wood. Caveat - don't shut the air control down too quickly, let the wood char first. You don't want to snuff out the fire or it will smolder and may backpuff.