normal pressure a valve associated with the uppermost one of the fluid inlets shuts off the flow of heating fluid to the uppermost one of the fluid inlets responsive to determination of the low pressure condition by the controller application_number US 201514617353 A description referring to the accompanying figures there is illustrated an aggregate bin control and monitoring system generally indicated by reference numeral 10 the system 10 is particularly suited for use with an aggregate heater bin 12 in the illustrated embodiment the bin 12 includes two upright side walls 14 and two end walls 16 joined between the side walls at longitudinally opposed ends in this manner the walls define a full perimeter containment spanning between an open top end 18 of the bin through which aggregate may be loaded to a bottom end 20 locating a hopper with a gate mechanism to control the discharge of aggregate therethrough the bin further includes a plurality of diffuser elements 22 spanning horizontally across the bin at each of three different elevations at each elevation at least one diffuser element 22 extends longitudinally between the two end walls 16 and a plurality of diffuser elements 22 span laterally between the opposing two side walls 14 perpendicularly across the longitudinal diffuser elements each diffuser element 22 comprises a rigid elongate channel which is formed by bending a flat.