In line tankless water heater with upper heating compartment, lower wiring compartment, and microswitch compartment disposed therebetween

A unitary electric resistance "in line" tankless water heater for interconnection to an electric power supply conduit, a cold water inlet line and a hot water supply line, said heater comprised of:

• a) a lower field wiring compartment defined by a cylindrical side wall, a removable bottom cover plate and a removable upper cover plate, said lower compartment having a port in said side wall for receiving said electric power supply conduit, and said lower compartment enclosing a terminal block mounted to the underside of said upper cover plate and positioned within said compartment for interconnection to power supply leads of said power supply conduit;
• b) an upper water heating compartment defined by a cylindrical side wall and an integral bottom wall from which there projects inwardly and upwardly a central post section, said upper compartment containing a circular electric coil heating element positioned around said post section in the trough space formed between said post section and said side wall and having separated coil-end terminals, and said upper compartment having a removable top cover plate including a cold water inlet port for interconnection to said cold water inlet line and including a hot water outlet port for interconnection to said hot water supply line;
• c) an intermediate compartment defined by a cylindrical side wall, the removable upper cover plate of said lower compartment, and said bottom wall of said upper compartment, said intermediate compartment enclosing a microswitch with electric power input leads interconnected through said terminal block to said power supply leads and with electric power output leads interconnected to said coil-end terminals;
• and
• d) heater control means within said upper compartment responsive to the entry flow of cold water from said cold water inlet line and cold water inlet port and to the exit flow of heated water through said outlet port and hot water supply line, said control means mechanically interactive with said microswitch to electrically energize said heating element when water flows within said upper compartment.