This article contributes to the sociology of education and technology by providing a cultural analysis of scepticism towards new technologies in school, using reactions to the telepresence robot 'AV1' as its case. AV1 is designed to connect 'homebound' students with their 'school-based' teachers and classmates. Despite its idealistic purpose, the robot has been met with significant scepticism by Norwegian school workers. To understand why, the article proposes the novel concepts of 'educational purity' and 'technological danger' to highlight the shared beliefs that underlie school workers' concerns. We find that school workers see AV1 as threatening key ideals of schools being pedagogically oriented, physically copresent and bounded institutions -- all concerns that reflect widespread ideas about how technologies tend to (not) function within educational contexts. In highlighting these symbolic tensions between new technologies and schools, the article sets a course for future studies into the cultural sociology of education and technology.