panel heating vs heating plant

panel heating and heating plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
panel heating	Yes	No	No	No
heating plant	Yes	No	No	No

As nouns, heating plant is a hypernym of panel heating; that is, heating plant is a word with a broader meaning than panel heating:

panel heating: heating system consisting of wall or floor or baseboard or ceiling panels containing electric conductors or heating pipes
heating plant: utility to warm a building

Other hypernyms of panel heating include heat, heating, heating system.

panel heating (noun)	heating plant (noun)
heating system consisting of wall or floor or baseboard or ceiling panels containing electric conductors or heating pipes	utility to warm a building