oil burner vs oil furnace

oil burner and oil furnace both are nouns.

Word	Noun	Adjective	Verb	Adverb
oil burner	Yes	No	No	No
oil furnace	Yes	No	No	No

As nouns, oil burner and oil furnace are synonyms defined as:

oil burner (noun)	oil furnace (noun)
a furnace that burns oil	a furnace that burns oil