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