Jotul 3cb burning problems

[sjmcd]

We upgraded from a Jotul F 602 to a 3cb over the summer. The Jotul 3 burned great all autumn and early winter with wood we had cut and seasoned. As we neared the end of our supply, we noticed it started to not burn as well. It takes longer to light and get going. Once it's going, the wood will have a nice flame for a little while, but then turns to a black block with a few red coals and tiny flames. We assumed it was because the wood wasn't as well seasoned. Then the glass got a crack in it. We saw that the glass had slipped in the brackets and assumed that caused the cracking. We replaced it with Jotul pyroceram from a local dealer. Then we bought some "seasoned" oak from a local guy. The same bad burn issue continues. It looks like nice wood, but perhaps it's not dry enough? THEN the glass cracked again. We returned to the local dealer and they think they had given us glass for a Jotul 3 F TD (due to price difference). This time we returned home with the correct glass, replaced the gaskets, and hoped for a better burn. But it is burning the same: long start time, good coals finally form, put logs in and they go -- the fire gets plenty hot -- but then turn black and don't let off as much heat. I have to stoke it frequently to keep it up and going and logs burning.

Do you think the glass breaking, wood, bad burn is all connected? Or is the glass a fluke and the wood just too wet? I can't find anyone else describing wood burning this way, so I'm at a loss.

 

[DAKSY]

Do you have a moisture meter? That's the ONLY way to tell the condition of your wood...

 

[jetsam]

Glass problems would cause only hotter fires, not cooler ones (unless your stove is actually designed to let air in around the glass, which is unlikely).

If you had an issue related to an air leak in or around the glass, you might have no ability to burn low, or uncontrollable runaway fires.

Get some dry wood and test it that way. If you have to, you can pick up a small load of ecobricks or even 2x4s and try it with that.

x2 for the moisture meter.

 

[Manly]

I have been burning a 3cb for nearly 20 years. Assuming you have proper drafting, it most certainly sounds like too high a moisture content in the wood. Quite a few times over the years I was relegated to burning wood that was not fully seasoned. It is difficult to start, requires full air open and you don't get much heat. I am talking about wood that was split, stacked and covered, but not quite aged enough. The Jotul 3cb is a small stove but we manage to use it as our primary heat source in our small ranch burning 3 1/2 cord each winter. Already burned through that amount this season since wife is home now. As far as the glass, that has nothing to do with anything beyond improper installation assuming you have the proper glass. I don't know about the newer models, but the old ones have meager retaining clips, and I didn't like the thin gasket they used. I used a flat, wide ribbon gasket the last time I replaced the glass gasket an it seals and secures the glass much better.

 

[DuaeGuttae]

I don’t really have insight for you about the cracked glass. It sounds as though you’re not new to wood burning, but I haven’t seen any mention of checking for an obstruction in the flue or a clogged chimney cap. It’s been a cold winter at points, and there might have been more condensation of flue gases, especially if your wood isn’t quite as dry as it should be. It really sounds as though there could be an obstruction of sorts, and you really want to get some experienced eyes on your chimney and cap.

 

[begreen]

The wood sounds like it is not fully seasoned. I don't think this is tied to the glass breakage.

How full is the stove being loaded. Is the wood touching the glass at times? Has the stove had any backpuffs? (small explosions in the firebox as it fills up with smoke.)

 

[sjmcd]

The wood sounds like it is not fully seasoned. I don't think this is tied to the glass breakage.

How full is the stove being loaded. Is the wood touching the glass at times? Has the stove had any backpuffs? (small explosions in the firebox as it fills up with smoke.)

I am not closing the door on the wood, or trying to fit in as much as possible. Once it's lit and going for a while, I have seen it roll onto the glass as the wood settles.

No backpuffs.

 

[sjmcd]

Do you have a moisture meter? That's the ONLY way to tell the condition of your wood...

I've ordered a meter but it hasn't arrived.

 

[sjmcd]

I have been burning a 3cb for nearly 20 years. Assuming you have proper drafting, it most certainly sounds like too high a moisture content in the wood. Quite a few times over the years I was relegated to burning wood that was not fully seasoned. It is difficult to start, requires full air open and you don't get much heat. I am talking about wood that was split, stacked and covered, but not quite aged enough. The Jotul 3cb is a small stove but we manage to use it as our primary heat source in our small ranch burning 3 1/2 cord each winter. Already burned through that amount this season since wife is home now. As far as the glass, that has nothing to do with anything beyond improper installation assuming you have the proper glass. I don't know about the newer models, but the old ones have meager retaining clips, and I didn't like the thin gasket they used. I used a flat, wide ribbon gasket the last time I replaced the glass gasket an it seals and secures the glass much better.

We replaced the brackets and gasket with the Jotul gasket kit. It was a thin, maybe 1/3 inch self-adhesive gasket for the glass. Does that sound like what you use?

 

[begreen]

I am not closing the door on the wood, or trying to fit in as much as possible. Once it's lit and going for a while, I have seen it roll onto the glass as the wood settles.

No backpuffs.

OK, a common reason for glass breaking is overtightening the glass retainer clips. The back puff guess was a long shot. It would take a monsterous back puff to break the glass.

 

[Manly]

We replaced the brackets and gasket with the Jotul gasket kit. It was a thin, maybe 1/3 inch self-adhesive gasket for the glass. Does that sound like what you use?

The thin self-adhesive gasket is what Jotul uses. Over the years I had to replace this glass gasket quite frequently. A few years back I used a wider flat ribbon style gasket. It lays flat, over the channel where the original gasket would lay. It protrudes the outer edge of the glass and also shows a bit of overlap from the outside of the door. I also put a piece between the retaining clips and the glass. For me this setup has held the glass more securely and absolutely no air leakage around the glass. I always developed air leaks using the original thin gasket material and the glass would eventual show movement when I would clean the glass. I will try to post a picture of the setup when I get home this weekend.

 

[sjmcd]

I don’t really have insight for you about the cracked glass. It sounds as though you’re not new to wood burning, but I haven’t seen any mention of checking for an obstruction in the flue or a clogged chimney cap. It’s been a cold winter at points, and there might have been more condensation of flue gases, especially if your wood isn’t quite as dry as it should be. It really sounds as though there could be an obstruction of sorts, and you really want to get some experienced eyes on your chimney and cap.

There are no obstructions. The chimney was swept last year and we burned oak for this first half of the year.

 

[edyit]

There are no obstructions. The chimney was swept last year and we burned oak for this first half of the year.

how dry was the oak? you'd be surprised how fast unseasoned wood can gunk up a chimney, and oak is one of the wood types that takes a few years to dry.

 

[DuaeGuttae]

There are no obstructions. The chimney was swept last year and we burned oak for this first half of the year.

No matter what you’re burning, the symptoms you describe warrant checking the condition of your chimney. Under seasoned wood causes creosote, not pine versus oak. Oak is probably more likely as it is denser and holds its moisture longer. The chimney could easily have a layer of creosote or a clogged cap, especially if you’ve been continuing to try to burn recently purchased wood (likely to be pretty wet despite any claims of seasoning on a seller’s part— there’s no legal definition for that, and most just count from when a tree was felled not from when the wood was split).

Chimney clogging can happen pretty rapidly. If you have a mesh screen at the top, just using paper or cardboard to get things started can start clogging the air spaces. Then you get less draft, then you start using more paper and cardboard to coax that damp wood to flame. The wood smolders because there isn’t enough air moving through, the smoky exhaust cools, you get creosote build-up.

I’m not an expert, and I certainly can’t say for certain what is going on with your chimney. If it were mine, and I couldn’t check or clean it myself, I’d get a professional to check it. Your description of it getting harder and harder to light really is indicative of progressive build-up in the flue.

I think the cracked glass is probably a red herring. I’m glad others can help you with better advice for that.