In this paper, an analytical solution for the temporal location of moving solid-liquid interface of a phase-change process, occurring in parallel plate channels, is presented. The motion of the solid-liquid interface is governed by the convection from the surface of one of the plates, while constant heat supply is assumed to occur on the surface of the other plate. The steady location of the solid-liquid interface is also determined. The variation of the Blot number versus the Fourier number is investigated. The results of this study indicate that simple analytical solutions for transient phase-change problems with heat flux and convective boundary conditions that are of practical importance to the people working in the held can be obtained. Copyright (C) 2000 John Wiley & Sons, Ltd.