The relief valve on the electric furnace(slowly) let most of the water in my system dump into my containment sytem a couple days after I shut my system down couple weeks ago. (I just replaced the relief valve-which is similar to the ones on hot water tanks-a year or two ago because it was leaking.) These are supposed to trip open when the pressure goes OVER 30 PSI but mine apparently works in reverse! It dumped some during the winter but since the water was hot, I just kept refilling it. Anyone ever have this prob??