Can you buy some well seasoned wood from a supplier in your area? Or maybe go to a friends place and borrow some just to see for sure that high moisture content is at issue here?
I feel for you. When I built my boiler years ago, I installed it in mid October, fired it up, and I was thoroughly impressed. I burned some seasoned campfire wood I'd had laying around, with the intent of cutting more wood on the weekend. That Saturday it got cold, and I brought home some white oak(live) that had been leaning over a hay field and causing problems with farm equipment. I could barely keep that stuff lit, and when it was burning, it didn't give off much heat. My neighbor came over, opened my firebox door, saw the water sizzling out of the ends, and told me to go and grab a load of his wood and just replace it with my oak. What a difference. Only hours earlier I'd been second guessing myself on my burn chamber design, and now hours later, I felt like I deserved some type of thermal engineering award.
Hang in there. I've heard that 250 is a pretty descent machine. You will figure it out.