We have had our Castle Serenity for a little over a year now. We have been burning it on temp with all factory settings until about a month ago with no problems. Now, we seem to have two conflicting problems. One is that the fire is going out before more pellets drop. The second is that the glass is turning black after a few hours. We took it all apart and cleaned the exhaust fan and ventilation system. Nothing changed. We opened the damper some and it just went out faster. We closed the damper some from factory setting and it is still going out and the glass gets dirty faster. Even set on the lowest possible temp (61) it burns on 1 most of the time so I changed it to manual and raised it to 2 and it isn’t helping. We haven’t changed the pellets we burn. It’s not just a couple bad bags because this has been going on for about a month. I’m about to just turn it off and huddle in my bedroom with a space heater! Any advice is greatly appreciated!