Re: Bio Bricks in Jotul Wood Stove??

[jholmes]

Interesting. I have a Jotul F3. The age is probably around 12 years, it came with the house when we bought it. Last year we decided to try burning Bio Bricks and it seemed it was working out well. But this season when preparing the stove for the winter, I noticed the baffle was warped, so much so that it did not seat correctly. We never stuffed the stove more than 6 bricks because I read the cautions before hand. I am just curious if it was from the Bio Bricks, or the age of the baffle? Is this why Jotul frowns on the use of them?? So now I am at a crossroads on weather to get cord wood, or Bio Bricks. I have replaced the baffle with a new one, but don't want to be buying another one next year either.

Jim
CT

 

[Shari]

ctburn,

First, welcome to the list!

Second, as a fellow Jotul burner I don't have the answer for your but hopefully one of the gurus on the list will come along soon and answer your question.

Shari

 

[begreen]

Were stove top temps monitored? If the stove top stayed under 650, I would guess that the stove and baffle are a bit older than thought and this is not related to the bio bricks, but this is just a guess. It's very hard to say what warped the baffle without knowing or seeing what shape the baffle was in before the bio bricks and knowing how the bricks were burnt. This would be pure speculation. Also, it sounds like the age of the stove is a guess. If the baffle is actually closer to 20 years old, then I would not be surprised that it needed replacement.

 

[My Oslo heats my home]

Is the F3 also a coal burning stove?

 

[BrotherBart]

Is the F3 also a coal burning stove?

No.

 

[Dexter]

Hi CT

I don't know if your model has a two-piece iron burn-plate/baffle. We have a Firelight CB that sees pretty heavy service (we turn on the furnace only when we leave the house for the weekend, otherwise burn 24/7 during the cold season.) We noticed that the top baffle would very gradually warp over about three years of this kind of use, even when the stove top (rear corner thermometer) usually doesn't get over 550. If yours is designed the same way, my guess is that it went through very gradual warping.

Regards

 

[agartner]

BioBricks are really dense and they pack a lot of punch. Air control is critical. The F3 looks to be a small stove, I could see things getting really hot in there if you let a half-dozen bricks go full cycle with your air wide open. I've had stovetop temps into the 800's using biofuel in my steel Kent Sherwood at times when I should of been more attentive.

 

[BrotherBart]

Yeah six bricks in a F3 is a whole lot more potential BTUs than that little firebox was designed for. The sucker heats up in the firebox long before the surface temps come up. My F3 starts kicking secondary combustion with the stove top temp only around four hundred degrees from a cold start because of the confined space in the firebox and the cast iron being slower to warm up. Whereas the big stove takes longer.

 

[jholmes]

Thank you all for the response-it helps to shed some light. Yes perhaps the stove is older than speculated. The baffle sagged in the middle, so the ends would flare upwards(should lay flat, and seat into the back baffle). It is one of their smaller stoves, but does heat the family room to our needs. Wow, 6 bricks can be too much for it too handle?? So if I decide to go with Biobricks again, I should only stack 4 bricks at a time?? The only reason I maybe partial to the Biobricks, is the convenience of storage, cleaniness, upkeep, and easy startup. Although I wouldn't mind burning wood again.
We here enjoy the stove, and just don't want to ruin the appliance with carelessness, or by something that we could've prevented. I will look into getting a temperature gauge too.

Thanx
Jim

 

[Freeheat]

I have used the liberty bricks as well but only 1 or two at a time, they are so dry and dense they pack a big punch. Never more than 2 in the stove at one time,

 

[spirilis]

I typically use a minimum of 5 bricks, 6 heats the house up a good bit (I like to use 6 in the wintertime), but the key to controlling burn rate is to pack them close together so you limit exposed surface area. With 5 bricks (plus a small piece of pallet wood) my Jotul eventually sees 700F temps for <30min, it's an older one with a larger firebox too (Jotul 8 1st-gen) but air control is key. The VC Defiant upstairs never gets above 600-650F with 6 bricks unless I include some pallet wood in the mix, then it can get to 700F on a good (proper drafting) day. My draft isn't the best though (the Jotul seems to be in better shape since it's downstairs thus longer flue path) so my situation may be different.

Note: The 700F temps are very close to the flue exit, which the Jotul 8 doesn't do a particularly stellar job baffling the gases from going straight up (some small part of the top-vented flue exit overhangs over the front of the baffle so there's no restriction at all, even; seems my stove would get more efficient use of its heat with a rear-exit) but the rest of the stovetop is usually in the 600's or upper 500's when this occurs. I use an infrared thermometer (Raytek Minitemp from amazon, knockoff of Fluke's IR meter) to check these temps.

 

[begreen]

I tried to closely follow the directions when I tested them in the Castine (F8 is predecessor). My first test charge was 13 bricks, closely packed with the top layer at right angles to the bottom layer to block off air spaces. This load gave me a nicely controlled burn in which the stove top never got over 650 °F. The second test was with 15 bricks, again, closely packed. That was one of the best and longest burns I ever had with the F400. Observing the fire, I was glad I had a stove with good secondary combustion.

One of the reasons for the nice long burn at a good sustained temperature was the secondary burn, which was the longest I had seen in this stove. I can't say for sure, but it could be a lot of the power in this product is lost up the flue without a good secondary burn. https://www.hearth.com/econtent/index.php/wiki/BioBricks/

 

[spirilis]

One of the reasons for the nice long burn at a good sustained temperature was the secondary burn, which was the longest I had seen in this stove. I can't say for sure, but it could be a lot of the power in this product is lost up the flue without a good secondary burn. https://www.hearth.com/econtent/index.php/wiki/BioBricks/

That is interesting. If I were to take a wild guess, I'd say it's the fact that these tend to burn in layers--they don't coal up very well because each exposed layer of the brick goes through all cycles of the burn process (pyrolysis + flame, charcoal, then ash) before the layers underneath burn, so it should provide a sustained secondary burn until near the end, especially with modern stoves w/ firebrick that keep it hot. I've opened the door when the firebox is fairly dark and bashed a brick with the poker, found tan unburned sawdust inside, which promptly caught fire and the firebox was full of flame for another 15-20 minutes or so. Yet if I don't touch it at all, in the end I end up with a pile of fine ashes with some charred sawdust mixed in (not a lot), so I know it burns through well enough without my fiddling around.

 

[jholmes]

Ok, ok I admit I did poke the bricks. I've decided to burn wood this year, only because it is more cost effective for our family. I will go back to the bricks when times are better. On the plus side, at least I can hear the crackling of the fire unlike the silent burn of the bricks. Picked up quite a bit from the responses--thanx.

 

[JohnJay]

I just had my Jotul F3 installed last week - getting 2 tons of Envi Logs this week.... Anyone have any suggestions, comments, thoughts? I grew up using a very old plate steal stove in the 70's.... Looking forward to using this one in a month or two.

Thanks in advance!

J.

 

[stoveguy13]

I just had my Jotul F3 installed last week - getting 2 tons of Envi Logs this week.... Anyone have any suggestions, comments, thoughts? I grew up using a very old plate steal stove in the 70's.... Looking forward to using this one in a month or two.

Thanks in advance!

J.

If the stove is new it will void warrantty to us anything but cord wood