Added a piece of 1" thick ceramic insulation "blanket" to the inside of the fire door. It fit so well that I did not even have to glue it. So far the results are pretty encouraging. There is a noticeable difference in the amount of heat coming from the door when the stoker is running. Cost for the insulation was $24, and there is enough left to do my brother's EFM as well.
I am only running the EFM for domestic hot water until the drum is empty, then I need to shut it down and clean the fines out. I also have a clean out tee to replace the 90 degree elbow currently on the flue outlet of the boiler.
This morning it is 12 degrees outside and the EFM is starting to get into a good rhythm. The basement seems cooler, and the door on the boiler is not smoking hot like it used to be, so I am pretty happy with the ceramic insulation.
At the same time I replaced the circulator that is between the EFM and the oil boiler, and I set the new circulator on "speed 2". Compared to the Taco 007 that was in there before, this should result in a reduction in flow rate between the two boilers. The temperature gauges confirm that - previously I saw hardly any difference in temperature from the supply and return on the EFM, now I am seeing about 10 degrees. Seems like a good thing to have a bigger delta between the heat exchanger in the boiler and the temperature of the flue gasses? Maybe that is a stretch...but the system is certainly quieter, and seems to be the most efficient it has ever been.
I timed it this morning. My fire went out and the oil was running when I woke up, the temp was 68. I turned the oil up to 72, snapped on the coffeemaker. Coffee took 7 minutes, oil furnace shut off at 14 minutes, LOL.