The thermal confinement within the confinement zone (between q ≈ 1 and q ≈ 2) of ohmically heated deuterium plasmas bounded by the ergodic divertor (ED) configuration in TORE SUPRA is studied in a 11/2-D analysis of the local power balance. Although the edge electron temperature and the mean electron density (ne) are both on average halved when the ED is applied, the mean electron thermal diffusivity χe shows the same density dependence as that exhibited by standard Ohmic limiter discharges, i.e. an Alcator-like inverse dependence on (ne) at low density (χe ~ (2.5 × 1019)/(ne)) and a saturation at high density. The ion thermal transport as low to medium densities in both limiter discharges and ED discharges is between 10 and 20 times that predicted by neoclassical theory. Comparing ED plasmas and limiter plasmas of the same density, a strong plasma decontamination is observed, with a reduction in Zeff by 1.0-1.5. The effective decoupling of (ne) and Zeff by the ED and the invariant behaviour of χe imply that electron thermal transport is only weakly dependent on Zeff in Ohmic TORE SUPRA discharges