Nuclear modification factor $R_{\rm AA}$ for electrons from semileptonic heavy-flavour hadron decays at mid-rapidity as a function of $p_{\rm T}$ in 0--10\% (left panel) and 20--40\% central (right panel) Pb--Pb collisions at \energy  = 2.76\,TeV. Error bars (open boxes) represent the statistical (systematic) uncertainties. The normalization uncertainties are represented by the boxes at $R_{\rm AA} = 1$. The previously published results from  have been updated using a new glauber model calculation .