Micro combined-heat-and-power (micro-CHP) technology has potential to contribute significantly to the UK's climate change strategy. This study applies a technological innovation systems (TIS) analysis to the UK domestic micro-CHP sector to better understand the dynamics of this emerging technology, identify policy options for enhanced system development, while also assessing the effectiveness of the TIS framework as an analytical tool. Interviews with key system actors are used to understand system functions, enabling an analysis of system development over time in terms of inter-functional relations, and a brief comparison with the Dutch micro-CHP system. Specific policy recommendations are made, including clarification of government renewable vs low-carbon climate change mitigation objectives, establishing dedicated targets, incentives and supports for adoption, installation and industry representation. A critique of the TIS framework highlights the dangers of selectivity with regard to key functional patterns, underdevelopment of consumer influences, and insularity with respect to wider influences on innovation.