Question: We recently installed a Large Convection "Consolidated Dutchwest" stove and we are experiencing smoke backpuffing into the room when the catalyst ignites. This doesn't always happen, only when the temp. is high in the catalyst (1200). The stove will also rumble a low repetitive hum as the catalyst approaches 1300. We immediately open the primary damper, and this stops the rumbling and clears the smoke. It also cools the catalyst, so when we close the damper, the burn is not as clean. We then let the stove burn down, and reload and restart the catalyst. Do you have any ideas as to the cause of this, and how we can correct? It scares the kids, and prevents us from leaving the fire for even a short time. Thanks, and keep up the interesting stuff! Answer: It sounds like the chimney and/or inlet air flow is "unbalanced" with the stove. Chances are that the chimney draft is too strong, causing the combustible gases to remain unlit as they pass through the converter...then, when they ignite--Boom...a backpuff. Or, the stove is set with too little primary or seconday air, which is causing too much unburnt fuel vapor to enter the catalytic are. Ideally, there should be a flame on the fire, not just a smokey burn. Besides adjusting the air, you may also want to install either a barometric damper or a turn damper (or both) onto the smokepipe. This will allow you to throttle the chimney to your liking.