coalnewbie wrote: The AK 180 is in the basement and the coaltrol is on the first floor. It all works perfectly and none of that oxygen dihydride stuff to rust things up.
That is true...when the furnace is in operation. When it sits idle over the summer, that is a different story. Then you have moisture and oxygen on both sides of the heat exchanger. As you know, proper maintenance is important, and you must take steps to prevent corrosion in the off season. If you treat a boiler the same way, it will easily last as long or longer than any hot air furnace.
For a long time I was not a big fan of the Coal Guns because of the the problems they had with puff backs. However, AHS listened and make some improvements to the design, and to my knowledge no one has had issues with puff-backs since upgrading to the new controls. Coal Gun's are pretty flexible when it comes to coal size. Most guys burn pea size, but buck burns very well also. You can even hand-feed larger sizes if necessary.
Are you planning to install an air-handler? Or just a water to air heat exchanger? Pipe the boiler to allow for easy addition of zones at a later date. A big cast iron radiator in the basement would make a great dump zone.