The configuration and composition of Radiant Floor Systems (RFS) are essential for an optimal thermal performance, seeking high indoor thermal comfort in buildings. When phase change materials (PCMs) are incorporated into radiant floors to provide thermal energy storage capacity, the system’s configuration becomes increasingly relevant. However, there are still very few large-scale experimental studies dedicated to the thermal performance of RFS incorporating PCMs. In this study, a new configuration for a RFS incorporating PCMs is proposed. The innovative RFS incorporates two macroencapsulated PCMs with different operating temperatures, selected to meet both heating and cooling demands. The thermal performance of a large-scale test specimen is experimentally evaluated under controlled conditions using a climatic chamber, subjecting the innovative PCM-RFS to different environment conditions, and comparing the results with a reference RFS. Despite the system’s ability to operate in heating and cooling, the herein presented work addresses only a heating scenario. The results confirmed that the PCM-RFS has the ability to slowly release heat over a significant period of time after the system is switched off, capable of maintaining the indoor temperature steady within comfort levels.