HotCoals said:You burnt the load up in 2.5 hours and even lost a degree or two?
I would switch back I guess.
Keeping the air open is going to keep the fire cooler and waste a lot of heat up the flue. The air needs to be closed down once the wood is fully aflame and a good secondary burn temp is reached. How far closed will depend on the draft, but usually it is somewhere between 1/4 open to all the closed.