The establishment of a high-fidelity simulation model for heating systems is crucial for practical guidance, as it serves predictive and evaluative purposes, offering accurate references for the operational management of actual engineering projects, thereby minimizing resource and cost wastage. This study, utilizing the Transient System Simulation Program (TRNSYS) software and focusing on an electric boiler water storage heating system in an elementary school, has developed a high-fidelity simulation model. Multiple TRNSYS (Types) modules were independently programmed, and the model's stability and precision were verified through error analysis. The model is capable of dynamically simulating the changes in supply and return water temperatures on both the storage and usage sides of the system under varying external environmental conditions and hydraulic states, achieving synchronous computation of the thermal and hydraulic characteristics of the heating system. The comparison and analysis of the temperature measurements at various system points against actual collected data revealed an average relative error of less than 5% across these measurements, indicating the simulation model's high accuracy and operational stability. It accurately and reliably reflects the thermal dynamics of the heating system, providing a reliable reference for practical application. This model is applicable for guiding the operational management of actual engineering projects and offers a scientific basis for subsequent system design and optimization.