Among heat accumulators, hot water storage tanks are the most widely used due to their low cost, simplicity, and ease of operation, as well as their low environmental impact. The temperature distribution within a hot water storage tank is a key factor governing the thermal behavior and hot water delivery performance of the system. This distribution is influenced by a number of operating and design parameters. These include the water inlet flow rate, inlet temperature, initial temperature of the water inside the storage tank, tank geometry, the tank diameter-to-height ratio, and the locations and arrangement of the inlet and outlet pipes. Variations in these parameters can significantly affect the temperature stratification and, consequently, the thermal performance of the hot water storage tank. The dependence of the efficiency of hot water storage tanks on many such parameters increases the importance of using mathematical modeling and numerical simulations. In the present study, a one-dimensional mathematical model was established to describe the thermal behavior of a hot water storage tank and subsequently validated against experimental data. The comparison between the numerical predictions and experimental measurements yielded anRMSEof1.85 °C, while the coefficient of determination was calculated as ܴ²=0.94, demonstrating a strong agreement between the model results and experimental observations. The analysis also showed that the storage tank could be completely discharged within 1980 s, equivalent to 33 min.