Here's a weird one.. starting this spring I noticed a little lag in my cat, something just didn't seem right, I would lite the stove get her cranking but once the cat was engaged the needle would only hover around the 12 oclock area, then slowly fall to the inactive zone as the burn continued. Sometimes the cat would go into the inactive zone when there was still a little fuel left over, I just figured the cat was settling, and that it basically is what it is. Last night I lit the stove burning only pine about 15% moisture content, as was the mentioned earlier I got the stove up to temp, closed the bypass and the cat rose up to high noon, a little over, I turned the thermostat down to 1.5, and the need fell to the 9 oclock position, which I was use to, just above active, looking at the chimney while the cat was active I still noticed whisps of smoke, its been like that since March, I didn't think twice.
Tonight we are experiencing the same temps so I loaded the stove with the same pine, before I lit the stove I decided dollar bill test the door gasket, now I only installed this stove in the beginning of December and I made sure the gasket was tight to the door at installation time, also looking at the gasket right now you would never see an air leak sign, the outside of the gasket is still white, while the inside gasket in brown / black. I did the test and noticed the bottom part of the door had very little resistance, the top and area by the door latch has some resistance. I decided to tighten the fixed door latch. Man oh Man.... that stove is operating like the day I bought it, using the same air settings, the cat is in the 2 oclock position, air setting at 1.5, no smoke out the chimney, you cant even tell im burning right now.
The point of this is if you have a newer stove and you experiencing some smoke out the chimney while the cat is engaged, and your using wood that is dry <20%, and you can only get the cat to the noon stage, do yourself a favor and check your door seal, check the whole thing, it makes a night and day difference from a loose latch to a tight latch. FYI the stove is a BK princess, basement install, about 20ft of metal chimney, its about 48 deg outside right now.