This raster dataset shows the modelled P50 distribution of the theoretical potential 'heat recoverable' (Hrec) across the northern and southern early Carboniferous limestone (ECL) in Great Britain (MW/km2), at a resolution of 2500 m x 2500 m. Hrec is calculated for resource temperatures greater than 50°C, which represents the minimum temperature required for direct use of heat from hot sedimentary aquifer resources. Hrec represents the proportion of accessible heat in an aquifer according to the USGS definition described in e.g. Muffler and Cataldi (1978). Its calculation is part of the research published by D J.R. Jones, T. Randles, T. Kearsey, T.C. Pharaoh, A. Newell (2023). https://doi.org/10.1016/j.geothermics.2023.102649. Areas of high uncertainty are delineated in the published paper and the theoretical potential of the recoverable heat is presented with very high uncertainty.