An experimental investigation of the melting process in the vicinity of a heated vertical wall in a rectangular enclosure is presented in this work. A flat-plate heat pipe was used to provide a uniform temperature source, The liquid how patterns during the melting process were captured and the instantaneous marching of the liquid-solid interface was presented. In addition, the temperature distributions in the phase change material were measured at the mid-plans as well as top and bottom walls of the enclosure. Three different heat transfer regimes were identified during the melting process. The parametric domain covered the range of Ra = 2.02 x 10(6)-2.61 x 10(7), Ste Fo = 0.001-0.125 and Pr = 803-1055 while the critical Rayleigh number where the transition from the conduction to the convection regime occurs was found to be in the range of 7.869 x 10(6)-3.237 x 107. It was found that the melt volume fraction and the time-averaged Nusselt number can be correlated by V/V-o = 4.73Fo(0.906) Ste(1.538) Ra-0.002 and (N) over bar = 0.0210Ra(0.387) Pr-0.0191(H/delta)(0.0621) respectively.