Getting SOME Smoke from chimney - Cat Stove - OK?

[777funk]

I notice that I'm getting a small amount of smoke after the fire has died down and the door is shut.

Here's how I've been burning:
-Light it with kindling. Hot fire fast
-Once logs are engulfed pretty good (flames coming from 3/4 of their length) I close the door
-Vents open enough to keep light to medium (4-6) blue flames 1 hour after lighting then only coals thereafter.

IF the house gets too hot, I'll close the vents down most of the way as long as I can still see coals glowing and the top of the stove is too hot to touch.

I'm still seeing smoke after a few hours of hot stove burn (thin and extends about 3' long past chimney). My glass is also turning pretty black by the way. Most of my burns have been near the back if the stove a good 10-12 inches from the front glass fwiw.

 

[begreen]

There should be no smoke at all. It sounds like the stove is being run too cool for this time of year and perhaps the chimney cap screen is starting to plug up? Could be the cat is stalling too. At what point is the cat bypass being engaged?

 

[777funk]

I usually engage the cat after the top is hot to the touch (2-3 seconds hot). This is 10-20 minutes after lighting. I leave it engaged as long as the top is hot. Chimney and all piping are new this season.

 

[begreen]

Caps can clog up in a few weeks if the stove is being run too low and/or the wood is not nicely seasoned. It's worth a check just to see how the stove has been burning.

 

[Highbeam]

I'm still seeing smoke after a few hours of hot stove burn (thin and extends about 3' long past chimney).

Sounds just fine.

There should be no smoke at all.

So I own a cat stove and can tell you, it is normal to have some smoke. It might be bluish, light, and intermittent but cats do not eat everything.

 

[Highbeam]

My glass is also turning pretty black by the way. Most of my burns have been near the back if the stove a good 10-12 inches from the front glass fwiw.

Every stove is different but burning small fires in the back of a cat stove cause the quickest accumulations of glass gunk. The glass is only exposed to heat from the fire, not the cat, and since we all burn a cold fire and let the cat make the heat it is tough to keep the window clean. Some designs are better than others, usually the ones with short burntimes or double pane glass.

 

[begreen]

Sorry, my bad I was interpreting this wrong and thinking the smoke was indoors. Yes, apparently cat stoves do release some smoke at times in the burn as reported by you and others.

 

[777funk]

Ah! yes, no smoke indoors but smoke at almost all times coming from the chimney.

 

[begreen]

Almost all the time would bug me. I can see it on startup, but would expect the cat to do a better job. Is the cat new?

 

[777funk]

The cat is probably stock. Also I measured and the wood humidity is 20-40% range depending on the species and piece.

 

[Highbeam]

Ah! yes, no smoke indoors but smoke at almost all times coming from the chimney.

Almost all the time does sound a little excessive. I can count on heavy smoke at the beginning of a load and then the light whisps intermittently for the remainder of the burn. Probably 50% of the time there is something visible from the chimney. I burn a very modern BK stove though and your 23 year old country stove might not have ever been capable of the same level of combustion. 1991 was a time when manufacturers were winging out some new technology to meet the tighter regulations.

 

[mellow]

You really should have a Condar Catalytic probe on that cat so you can see what temps it is running, that will let you know if the cat is stalling.

http://www.condar.com/Catalytic_Thermometers.html

 

[Tenn Dave]

The cat is probably stock. Also I measured and the wood humidity is 20-40% range depending on the species and piece.

Isn't that very wet wood? Could that be part of the problem? maybe the cat can't keep up with all the smoke the damp wood is producing?

 

[begreen]

Isn't that very wet wood? Could that be part of the problem? maybe the cat can't keep up with all the smoke the damp wood is producing?

Yes, this wood is not fully seasoned. That will smoke more and produce less heat.

 

[mellow]

And potentially thermal shock the cat to the point where it crumbles and does not work anymore.

 

[dougand3]

wood humidity is 20-40% range

That is WET wood. You want 15 - 20%. Try a burn with grocery store bundles, cut up pallets or 2 by scraps (non PT).

 

[Charles1981]

My suspicious would be a failed cat (crumbling, cracked, ect or just disintegrated). Be nice to get a first hand glance at it...the wet wood isn't great either.

 

[Kool_hand_Looke]

Possibility of steam?

I know he said after a few hours.

The "thin, extends 3 ft. past the chimney" spells steam to me.

 

[777funk]

Yes, this wood is not fully seasoned. That will smoke more and produce less heat.

I'm sure this is the case. Even so it's producing WAY more heat than we'd like. We're using four 8" diameter splits (20" length) per 24 hour period and our 1200sq-ft house is holding at 80 to 85F with outdoor temps of 45F day and 35F nights. I'm afraid to turn the burn rate down because I want the cat hot. I will be cleaning the flue frequently for this first season.

And yes to others mentioning the cat, I pulled it and it looks ok for most but there are a few cells that crumbled leaving a 1/2 hole in one or two places (out of 8x12x2 approx worth of 1/8" spaced cells).

 

[begreen]

Feed it less fuel if you are way too hot. Wait until it gets cold before filling the stove.

 

[777funk]

Thanks! I'd read somewhere that it's good to always keep the stove filled.

Is there a way to keep the house around 65F or so and still keep the cat hot? This stove would barely be smoldering one or two splits at that temp and I'd be afraid the cat would stall or the fire would almost go out. I'm still learning this thing though.

 

[begreen]

3-4 medium sized (3-4") splits should do.

 

[Woody Stover]

II'd be afraid the cat would stall or the fire would almost go out. I'm still learning this thing though.

Yep, get the probe and you will know what's going on at all stages of the burn. My neighbor has a Country Flame BBF. On that stove, and on the Buck 91, I can see the cat glowing early in the burn if I look in through the bypass rod hole at the proper angle. Later in the burn when the cat is no longer glowing, but still burning, you'll need the probe to know if the cat is still active. Do you know how new the cat is? It could be that it either needs a distilled vinegar/distilled water simmer to revive it, or it could be on its way out if it's 5+ yrs old. Like Kool Hand said, could just be steam if it's disappearing after several feet away from the stack. On a humid day steam will carry further, though. But wet wood will cool it and that could result in unburned smoke getting past it. Downwind of the stack you should be able to smell weather it's actually smoke.

Probably 50% of the time there is something visible from the chimney. I burn a very modern BK stove though and your 23 year old country stove might not have ever been capable of the same level of combustion. 1991 was a time when manufacturers were winging out some new technology to meet the tighter regulations.

Unless I have the air open and flame in the box at the beginning of the burn when a lot of wood is gassing, I don't see any smoke from my stoves for the remainder of the burn (haven't been able to observe the Buck as much since it's not at my house.) I'm gonna guess these Country Flames haven't changed over the years and should work fine, but I could very well be wrong...