Correct me if I'm wrong but I think I recall reading a post about someone developing a programmable fan controller that adjusted fan speed in relation to stove temp. Yes, I've searched and have not been able to find anything. Can anyone point me in the right direction? The reason I ask is because our shop uses a Central Boiler Pallet burner http://www.centralboiler.com/models.php If you take a look at the pics in the link you'll see the louvered panels on the front doors, they each have a fan in them that forces combustion air into the fire. They also have a damper door that closes when the fans shut off (at a set water temp of 180 degrees). We have been having problems with the unit "backpuffing", at times it can be somewhat violent. This typically happens when the damper doors open after being shut for a period of time. We would like to find a controller that varied the fan speed both up and down instead of just cycling them from "off" to full throttle to "off" again. Any help appreciated. From what I remember the unit I read about here was not designed to control intake air fans BUT hopefully could be adapted to such a setup.