In this report, impact of melting heat transfer on nanofluid heat transfer enhancement in presence of magnetic field is simulated. Innovative numerical approach is utilized namely CVFEM. KKL model is taken into account to obtain properties of CuO-water nanofluid. Roles of melting parameter (delta), CuO-water volume fraction (phi), Hartmann (Ha) and Rayleigh (Ra) numbers are demonstrated in outputs. Results depict that temperature gradient augments with rise of melting parameter and Rayleigh number. Nusselt number detracts with rise of Lorentz forces. At higher concentrations, nanofluid has greater merit to be used for heat transfer enhancement. (C) 2017 Elsevier Ltd. All rights reserved.