In this study, latent heat storage enhanced with heat pipes is examined. The hot fluid carrying tubes are U shaped to improve heat transfer specifications. The effect of the number of the tubes as well as the angle of the tubes' plates are analyzed which necessitates the examination of at least thirteen models. RT-35 is applied as the phase change material and water as the hot heat transfer fluid (HTF) flows through the U-shaped tube. The enthalpy-porosity is applied to consider phase change within the model. Liquid fraction, phase change material temperature, heat flux, the heat input of the heat pipe and the temperature differences between the HTF inlet and outlet are described for the studied cases. Results indicate that by locating the heat pipe around the single pipe heat storage system, the melting time reduces up to 91%. It is also observed that for the tube plant angle of 30, by increasing the number of HTF tubes to two and three, the melting time reduces up to 12%. While the melting times for the double-tube and triple-tube cases are almost the same. This reduction for double-pipe of 90 plate angle is 17% and for the triple-pipe of the same case is 24%. As the angle of the HTF plate rises the melting time reduces. (C) 2019 Elsevier Ltd. All rights reserved.