I have a 4.0 I installed in parallel with my LP boiler using a dual boiler control with outdoor reset. I'm heating 2100 sq/ft main floor baseboard, 2100sq/ft walkout basement with radiant and indirect water heater. House has 2-9' and 4-6' glass doors on the north side and the basement is 2/3 exposed, located 130 miles north of Green Bay,WI. I light it in Sept and burn into May using 9 ton per year. I load every 4 days in the middle of winter or weekly in spring and fall and empty a scoop of ash. Once a month I pull the turbulators and brush or scrape the tubes. Boiler has lots of adjustments to control output and idle. Built in safety switch for hopper door, fire suppression in auger channel and overheat protection coils. Only issue I've had was of my own creation. Even my wife has lit it when I was not home so very simple operation. Easiest way I have ever burned wood. Haven't used corn, too expensive living on the northern edge of growing range for corn most is trucked in, but we have 3-4 pellet mills within 70 miles. I purchased this used but I would pay retail had I known how simple the operation is.