Rob is having such great success this summer with his new Hydrostat controller (which has dramatically cut his daily consumption down to about 14 lbs. of coal for DHW) that he has inspired me. Based upon his suggestion to me in a private conversation, I just took down the set point of the Honeywell L4006A aquastat on my AHS S130 Coal Gun to 170 degrees (from the previous 180, where it has been since day one).
Now my boiler will fire up the fan at 160 degrees and shut it off at 170 (vs. firing it up at 170 and shutting it down at 180). I'll give this a try and see if it lowers my daily consumption for DHW (which is currently at about 14-1/3 lbs. for UAE Harmony coal, or 15 lbs. for Blaschak), while maintaining a fire. If anything, it puts me 10 degrees farther away from triggering my 215 degree dump zone, which I just noticed to be in action yesterday. Dumping to the dump zone in the summer is a waste of good coal, and it heats up my basement when it least needs it. My biggest concern is keeping the fire lit, which was never an issue with the L4006A set at 180 degrees.
Rob, are you using the Hydrostat's new feature called 'Thermal Targeting', or are you using 'Outdoor Reset' to achieve your super results with the EFM?