In Europe, heating accounts for the largest part of energy consumption and GHG emissions of the residential sector (EU, 2021). Most of the scenarios aiming at carbon neutrality rely on a combination of improved energy efficiency (EE) and lowered indoor temperatures in a perspective of sufficiency. While many studies and tools, including Energy Performance Certificate, describe the EE of the housing stock, little is known of the current heating behaviours, which are assumed to change toward sufficiency. Before imagining where we could go, we answer the question: where do we stand right now? This paper describes French households’ heating behaviours in 2018, from a representative survey of 4000 people. First, patterns of declared temperature levels, by room and time of the day, reveal a range of spatial and temporal management behaviours. Then a “heating management” typology is analysed in relation with households’ demographics and equipment (building, heating system, control devices). Finally, the energy savings potentially resulting from a change of behaviour toward sufficiency is estimated. Strikingly, most French households do manage temperatures, either manually or through programming devices, achieving a much lower average temperature (in time and space), than their maximum level of comfort. Temperature depends mainly on the heating system quality: poor equipment only allows lower temperatures, while energy-efficient systems produce higher temperatures. For low-carbon scenarios, this work shows a large part of the potential for lower than 19°C indoor temperature is not available for future energy savings. Moreover, the deployment of heating control devices promoted in energy policies is unlikely to help a temperature reduction, given people without devices already manage their heating. However, the use of these control systems could mitigate the rise of temperature driven by the spread of more efficient heating systems and could provide controlled flexibility to the electric grid.