Heat transfer enhancement during phase change is important in design of latent heat thermal energy storage system. This paper presents a practical study of heat transfer enhancement of paraffin wax existing in single slope solar distiller base and sides. Aluminum powder was added to paraffin wax to enhance its thermal conductivity. Three distillers were fabricated; one without any modification, the second took the advantage of placing PCM inside it. The third one used PCM with aluminum powder to enhance its thermal conductivity. The practical tests were conducted in Baghdad – Iraqi weathers at January and February, 2013. The results show that aluminum powder ameliorated phase change materials exhibit enhanced thermal conductivity in comparison to the base material. Adding aluminum powder PCM increased distiller productivity as well as increased distillation time