check water pressure switch connection, normally gets blocked with old systems need to drain boiler to do this or you'll get wet. to find connection look for switch with three ( normally) wires on front and a 3/8" thread at rear. i dont have the manual in front of me but it should be listed on last page in spares list.if this does not work check pump spindle is not stuck. small screwdriver on impeller under chrome cap, rotate with POWER OFF!
gary, January 2009
