Is it possible that you are using RailCraft's World Anchors, therefore meaning you will need to supply them with enderpearls to work? (this CAN be changed in the railcraft config) If you are using some other method like the ChunkLoader from ChickenChunks, I'm not quite sure what could be causing your issue. If it is a problem to keep the boiler fueled, you could always think about just burning the blaze rods in a generator for EU, then using electrical engines for your MJ production...Just a thought, although steam boilers are certainly the way to go if you have the means of keeping them fueled. Best of luck!