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