... I started heaping the coal up in the middle of the firebox in my Harman SF-260 boiler. I was filling to the top of the fire brick and making the top of the coal level with the sides. In a Harman SF-260 boiler, the fire bricks are not placed vertically along the sides of the firebox (they're placed horizontally for some reason
) so that made for not-so-deep coal. The middle portion of my coal load is now twice the height it used to be. Now when I go to shakedown and refill, the coal fire is in much better shape than it used to be. I would occasionally lose the fire before I started mounding it up in the middle.