pumping station vs pump house

pumping station and pump house both are nouns.

Word	Noun	Adjective	Verb	Adverb
pumping station	Yes	No	No	No
pump house	Yes	No	No	No

As nouns, pumping station and pump house are synonyms defined as:

pumping station and pump house: a house where pumps (e.g. to irrigate) are installed and operated

pumping station (noun)	pump house (noun)
a house where pumps (e.g. to irrigate) are installed and operated	a house where pumps (e.g. to irrigate) are installed and operated