1975gt750 wrote:yes i do have a draft blower. i have it plumbed in series with the feed of the coal boiler going into the retun on the oil burner and then out to the house. i am currently running four circulators three are for heat and the other is for the hot water tank. i currently have hooked up the thermostat to the aqua stat on the coal boiler from my erie boler controls on the oil burner. seems to have cut some of the lag time. now when circulators come on the themp drops to about 155.on the coal boiler and seems to recover within 20-30 minutes up to 180 to keep up with demand. if you need some pics i will have to get some i can also give you a hand drawing of the plumming to detrmine where things are. thanks for the imput. one other quick question what did you think of my readings are they in line stack temp/draft/coal cunsumption/temp differential
let me know
Your objective is to make uour oil boiler is an automatic back up to your coal boiler? i.e. no intervention by you? Is that correct? That is something I cannot help you with. I am not familiar with what it takes to do that.
If it were me I would shut down the oil boiler and have a single pole double throw switch to prevent simultaneous electrical operation and install by-pass valving. All trim and controls would be shared by the two boilers. Then the boiler is available for use while away for long periods and to run your hot water in the summer. Otherwise your keystoker is reliable enough for the winter.
As for your readings, I don't think they are out of line but I don't know the unit. a 180 to 155 drop to satisfy a load is nearly ideal. Why it takes 20 minutes to recover is a matter of stoking.