<p>Focusing on the urban landscape of Amman, Jordan, this paper examines the governance challenges of renewable energy transition as it intersects with heterogeneous energy infrastructures and diverse thermal practices. Solar thermal water heaters, which are a small-scale form of distributed thermal power assembled from glass, bronze, and steel, are a key part of Amman’s urban thermal landscape. Drawing on ethnographic engagement with Amman’s solar thermal industry, this article reveals how the labor of solar thermal maintenance and repair iterates an alternative urban energy configuration that reshapes the built environment and the trajectory of energy transition. This alternative energy configuration illuminates the pivotal role of labor in shaping energy transition pathways, and the critical ways that heterogenous energy configurations both reproduce and challenge broader political economic relations. In dialogue with recent scholarship on the incremental, processual, and propositional dimensions of heterogeneous energy infrastructures, this paper brings critical focus to ‘unruly’ technologies and the labor of thermal maintenance and repair as key arenas of prefigurative politics that can inform broader research on thermal sustainability and the governance of global renewable energy transitions.</p>