That depends. The original house DJs didn't define "house" as a particular style of music at all, but rather the combination of all the different styles and the vibe of the club(s) or parties it was played in. Kraftwerk were definitely a part of the typical house DJ sets, but so were a lot of other bands whose music was of several very different styles.

House didn't really come to mean what we think of as "house" today until Detroit had already started the "techno" thing, at which point "house" became a somewhat smoother form of dance music that also used mostly electronic instruments.