I too have an Attack FD-42 coal boiler. While, in all honesty, my dream boiler was an AHS-130, the budget mandated that the FD42, at half the price, will have to do. It is plumbed in-series with my Burnham C-4 oil boiler; the plumbers were finally able to finish it up on 12/31/08, and I spent New Years Day firing it up for the first time. Started with a nice hardwood fire that took off like a rocket, (excellent chimney draft) and let it burn down and slowly added coal(Nut) until right up to the bottom of loading door opening. The boiler burned very well for several days on a 12-hour load and riddle schedule, and made the house quite toasty in near ZERO weather. However, I was having difficulty finding clear instruction on the "slicing"/"knifing"/ "riddling" procedures, as there are only very generic and vague references to ridding in the Attack manual. This boiler is identical or nearly so to the Sime Solida, Buderus G131 and G112, as well as several other central/eastern european models, so I was able to glean pieces of info from other manuals, and string most of it together. I have come to the conclusion that this type of boiler is so ubiquitous in eastern europe, that providing "riddling" instructions in the manual is probably akin to stating that one must "close the door when leaving the house"; but I didn't grow up in eastern Europe... Anyway, after 4 days, I nearly lost my fire, but was able to revive it, several days later I did in fact lose it for real. So yesterday I tore it down and started over. In the mean time, I have clarified the riddling procedures a bit, thanks to Craig, the webmaster at Hearth.com(Sorry NEPA), who used operate and sell these as "Sime" units from Italy. The lessons I've learned so far, are that the boiler seems to like slow and gentle loading, over about 70% of the coal bed at any given time. I upped my low-limit on the inter-boiler circulator aquastat to 150 F, and the FD-42's draught regulator to a little under 70 C (165F). Also, once it is going, it seems to just LOVE a little bit (1/4"-3/8" opening) of over-fire (secondary) draft, with the smoke damper set at about 50% open, and the the coal bed about 2" below the bottom of loading door; and once it's going, don't FUSS with it!!! I am hoping to keep riddling manually, but if I keep losing the fire every 4-5 days, I think I will opt for a set of shaker grates. I took this on as a challenge to learn a new skill, and I am committed to learn it, if at all possible. But I do need to heat this house.... Here, in Northern New England, no one has fired coal boilers in a very long time, so there are really no "old-timers" to access as a resource. Firewood has always been plentiful and relatively inexpensive if you have the connections and are willing to do the work, and is just part of the local culture. You NEPA folks will probably find this strange, but Coal, unfortunately just is not on anyone's "RADAR" screen up here. Though that is changing slowly. A few of us brave souls did the math, and were venturesome enough to give it an honest shot, and I like it, but it is an artform for sure. If all else, fails, I'll buy shakers.