heater vs steam generator

heater

noun
  • A person who heats something, for example in metalworking. 

  • A dead heat; a race in which two or more competitors reach the finish line simultaneously. 

  • A medieval European shield having a rounded triangle shape like a clothes iron. 

  • An extended winning streak. 

  • A device that produces and radiates heat, typically to raise the temperature of a room or building. 

  • A fastball, especially one thrown at high velocity. 

steam generator

noun
  • a type of boiler fitted in a diesel locomotive or another rail vehicle, which provided steam heating in steam-heated passenger trains that had previously been hauled by steam locomotives. 

How often have the words heater and steam generator occurred in a corpus of books? (source: Google Ngram Viewer )