Product Service Systems (PSS) designers are increasingly signaling the importance of emotion. However, emotion is yet to be theoretically and empirically studied in PSS design. This paper offers a conceptual model as well as an in-depth field study of the design of an emotion-centred PSS. While the analysis is inductive, it draws on related concepts from structural appraisal theory and structuration theory to further conceptualise the findings. The notion of ‘emotional chain reactions’ in the stimulation of user agency is put forward, producing implications for PSS design theory and practice. For the latter we suggest an emotion-based blueprinting technique.