Energy feedback is a prominent feature of policy initiatives aimed at reducing domestic energy consumption. However little research has been conducted on the phenomenon of energy monitoring itself, with most studies looking at whether, and how, feedback impacts on energy conservation. This paper aims to address that gap from a practice theory perspective. In particular we: set out the difference between energy feedback and energy monitoring; define the practice of energy monitoring; and investigate the rationale and qualitative experiences of those performing energy monitoring. An online energy feedback tool ('iMeasure') was the basis of the case study. A netnographic analysis of online discussion about the tool informed complementary in-depth interviews with ten current/former iMeasure users. We found energy monitoring to be a distinct practice that focuses on measuring and identifying energy use trends and requires specific know-how to perform. However, its connections to other household practices were weak and, for those who did perform monitoring, there was no guarantee that this practice would reorganise other practices to induce household energy saving. In fact, monitoring often followed decisions to make energy-related changes, rather than prompting them. We conclude that policy expectations need to be reframed in terms of how energy monitoring tools are used.