A low water sensor within the vessel is connected to a relay coil with contacts interrupting the flow of electrical energy to the heating element when water is beneath {HEAD ~ the level} of {TAIL ~ the sensor} 
A low water sensor within the vessel is connected to a relay coil with contacts interrupting the flow of electrical energy to the heating element when water is beneath { HEAD ~ the level } of { TAIL ~ the sensor }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL