Datasets contain experimental data for a thermal storage tank. In the datasets provided two experiments are carried out - one where the tank is filled only with water and the second where part of the volume in the top portion of the tank is replaced by containers containing phase change materials. In both cases, the system is firstly heated up to 65 °C. After water and PCM has reached that temperature, the system is being cooled by a direct flow of cold water. Temperature measurements are logged on the side of the tank describing different levels within tank. For the measurement of PCM, temperature sensor is placed inside the PCM container. Data can be used to validate mathematical models of the latent thermal storage systems. More detailed information in added Description.pdf file.