Black catlyst cover

[Anthony09]

I have new Vermont encore. I have done my break in fires, and immediately on starting first one a good portion of the ceramics in back turned black. Is this normal? Also should closing air supply all the way make fire go out or just slow down?

 

[stoveliker]

If you turn down the stove a lot, you'll get creosote in the firebox. But the cat should clean the gases up before they enter the flue. So this could be normal.

For my cat stove I can extinguish all flames leading to a smoldering heap, the smoke of which is combusted by the glowing cat.

As long as your cat remained in the active temperature range, this should be fine I think (but I don't know your stove).

 

[Ashful]

There is often a limit that, when turned down too far, you'll stall it. A "stall" means any combination of the catalyst falling out of active reburn and usually unburned fuel left in the firebox. On many cat stoves, you can turn down to where it appears there is no fire remaining in the firebox, just black smoking wood. As long as the combustor probe thermometer continues to read above 500F and your plume continues to stay mostly clear, you're burning clean. If plume goes black, or if combustor temp drops below 500F, or if the thing just stops consuming wood altogether, then it's time to try again with a bit more air.

This floor of how low you can go will come up a bit in warmer weather, and drop a bit in colder weather.