Yes I have it hooked to a thermostat, that part doesn’t seem to be an issue at all. I’ll try this tonight and see what it does. I know it’s clean, I sweep the pipe every ton, and have been doing it even more lately since the ash isn’t burning as completely as it used to.R-read thread again. You're in t-stat mode, hi/lo? You say heat level 4? That will be huge flame. Suggest putting feed rate and comb fan rate back in factory settings. Having the damper fully open, it will have difficulty lighting. If your exhaust path is clean, what you are saying doesn't make a ton of sense, any error flashing lights on board? I'm wondering if your control board took a hit... one thing though, I'd suggest getting the stove to run normal in manual mode if possible, then go from there, to see if board is working normally.