Currently the majority of homes in Belgrade are supplied by the city owned heating firm and few residents can regulate the temperature of their radiators. The heating is switched on in October and off in April and residents pay a fixed fee for the service all year round. Arguing against the wastefulness of this system, the city is altering its material and regulatory landscapes to move from supply side operations which dispense equal amounts of heat to every radiator in the city, to demand side operations which aim to give residents control. Homes can be purged from the intrusion of a mistrusted and illegitimate state through the thermostatic meters which promise to create the autonomous individual. Calls that challenge the ethics of asking residents to pay for the new system with consumer credit are met by the argument that there is nothing fairer than allowing people to pay exactly for what they consume. The rhetorical ideal of a responsible consumer is undermined, this paper argues, by the technical reality that keeps the radiators connected to the city’s system. Using ethnographic research carried out in two tower blocks and two low rise buildings this paper takes a material culture framework to explore the anxiety that radiators bring into homes. It argues that as hot water flows from one flat to another, it troubles the boundaries of responsibility, undermines ownership and leaves residents uncertain of their own role in the liberalising state and the globalising energy market.