That dial on the side.....I could never master what that thing does, if 1 1/2 turns open works for you then thats it. I think mine found a happy place at about 1/2 turn open. If you want a hot cat fire run the primary air open about half way, this will get things good and hot although I'm not sure I would leave it overnight open more than a good 1/4. Remember you have a convection stove (iron box inside an iron box with an airspace in between) so stove top temps will not get super hot, you can't boil water on the stove top, steam yes but rolling boil no. Try the thermometer on the side loading door for temp readings as this is only one layer of iron between the fire and the room. The hottest mine ever got was unintended when the bypass damper was left open and the primary damper wide open. The stove was cranking heat and as far as I could see didn't hurt anything. I forget, what is the cat operating range on the probe? I seem to remember temps on that gage going considerably higher than 750 before overfire during normal heating temps. I just remembered something else, with mine if you really got it cranking getting ready to close bypass, the primary air damper would become hard to operate/close. This happened to you yet? No worries, keep experimenting, avoid the too hots and the too lows and you will be fine. Going into spring don't be surprised if getting a full blown cat engaged fire is too much heat, you may find that burning a few splits on low air/bypass open is just the ticket. Good luck!