Our Encore has started puffing smoke out from around the griddle occasionally, and nothing I can do seems to effect it. We got a terrific chimney, so I can't believe that draft can be the problem (about 25" from flue to top, rises well above nearby roof peak, 8" round ceramic flue tiles). I've also tried opening a door or window to see if that helps, and it doesn't. Puffing is very slight, just a quick wisp or two, so you have to be looking right at it to notice it and even then it can be almost subliminal.
Stove is 20+ years old and was rebuilt last winter with the full fireback/refractory kit, for the second time.
Outside conditions seem to have little effect - we have caught it puffing when it was warm outside and when it was cold, and when it is windy and when it is dead still, and at any thermostat setting from lowest to highest.
Generally happens with a well developed wire, that it is say, some hours into a burn and, of course, only when the stove is in downdraft. The wood we are using is not two-year bone dry, but pretty good dry cut early spring and stored inside.
The griddle seal was replaced a several years earlier, not as part of the rebuild last year, but passes the dollar test. I am tempted to replace it anyhow, but my feeling is that smoke can always find a way to get out if the pressure inside the stove gets higher than the pressure outside, and that it is the draft, not the airtightness of the stove that keeps the smoke where it belongs.
The first time it did this I cleaned the cat, which was fairly obstructed, and it seemed to cure the problem for a while, but it started puffing again a few weeks later (or we may have never stopped, but we just didn't notice, as it doesn't happen continuously). I cleaned the cat again, but it made no difference.
I thought the problem might be that the thermostat was starving the fire too much so it would have mini-explosion when it got a hit of air, like an old Shenandoah, but it happens even when the air door is open.
One possibility. We are currently using a stainless steel catalyst from Condar. The holes in it seem smaller than on the ceramic style, and may be just clogging easier. Still, you'd expect it would go more than a week without cleaning.
Stove is 20+ years old and was rebuilt last winter with the full fireback/refractory kit, for the second time.
Outside conditions seem to have little effect - we have caught it puffing when it was warm outside and when it was cold, and when it is windy and when it is dead still, and at any thermostat setting from lowest to highest.
Generally happens with a well developed wire, that it is say, some hours into a burn and, of course, only when the stove is in downdraft. The wood we are using is not two-year bone dry, but pretty good dry cut early spring and stored inside.
The griddle seal was replaced a several years earlier, not as part of the rebuild last year, but passes the dollar test. I am tempted to replace it anyhow, but my feeling is that smoke can always find a way to get out if the pressure inside the stove gets higher than the pressure outside, and that it is the draft, not the airtightness of the stove that keeps the smoke where it belongs.
The first time it did this I cleaned the cat, which was fairly obstructed, and it seemed to cure the problem for a while, but it started puffing again a few weeks later (or we may have never stopped, but we just didn't notice, as it doesn't happen continuously). I cleaned the cat again, but it made no difference.
I thought the problem might be that the thermostat was starving the fire too much so it would have mini-explosion when it got a hit of air, like an old Shenandoah, but it happens even when the air door is open.
One possibility. We are currently using a stainless steel catalyst from Condar. The holes in it seem smaller than on the ceramic style, and may be just clogging easier. Still, you'd expect it would go more than a week without cleaning.