I was considering replacing the 3/4" loop in the stoker with a coil, the recovery is very slow and when the DHW demand is high we run out of hot water, I have to switch on the oil burner to heat up the tank. I'm running a burn of approx. 1 1/2" on the grate for the summer, I have no method of increasing the burn other then to lengthen the carpet travel. I have a rheostat on the stoker motor but changing the speed doesn't have much of an effect on the burn size, it really performs no useful function.
I was thinking of this:
Replacing the loop with a coil, installing a timer to run the combustion fan and the stoker motor as needed to keep the fire going (the fire will go out in less then 15 minutes with no power), and connecting the aquastat in the tank to run the motors continuously when water heating is needed. I would set the carpet travel for the maximum burn length recommended by Alaska. I also would leave the small circulator running continuously, as it is now, to prevent boiling in the coil during periods when no heating is needed. My goal is to keep the oil burner out of the loop as much as necessary.
I need info on sourcing the coil and sizing it as well as the timer, which would have to be capable of running the motors several times an hour.