I'm in my basement right now with the oil burner running. Yeah, I did it - I fired it up. I have the L8148A aquastat controller hooked to my Weil-McLain 140k BTU boiler and what I'm trying to do is help the EKO maintain the temp for a while while I do some analysis - as my heat got so low last night it would have taken all day for the wood unit to get the house warm again. The wife is home on materiney leave until at least January, but I'm worried that once she goes back to work, especially in the coldest months of the year, we may need oil to back up the house heat. So here's my problem. The L8148 only has a "high limit", and its lowest setting is 180 degrees, not sure what the differential is. I would rather have a relay that comes on when the boiler temp gets much lower than that - perhaps 120? I can sustain hot water (75 gallon tank) at 120 and can get the house to temp and maintain it between 140-150. Is there a way to do this with an add on (the sticker on the stat mentions a series 60 control but nowhere can I find out details on it).? Or should I change the relay? To what? Searching through back posts, it is apparent that perhaps I should re-plumb in parallel instead of in series, as I have huge heat loss through the chimney on the oil boiler... As I'm typing, the boiler shut off at 180 and its now down to 170 and hasn't come back on yet. So I guess my short quesiton is about a new or add on unit to control the oil boiler the way I want. Keep in mind that my Oil boiler and EKO are seperated by about 150 feet.