Hi folks, I'm a longtime lurker who made the leap this fall into the world of wood heating. My weapon of choice is a Harman PB105 pellet boiler. We kept our old heating unit, a cast iron Burnham oil boiler, as backup. So far we're thrilled with the unit. We had a little problem with over-pressurization but solved it with a larger expansion tank. I had a pro do the installation, BTW.