Both intermittent and continuous heating are widely used for radiant floor heating systems in Korea, Intermittent heating circulates hot water according to a predefined schedule while the continuous heating controls water flaw using thermostat control units. The standard version of SERI-RES has been modified for the numerical simulation of the problem. Results show relatively large temperature swings in the case of intermittent heating with solar availability, although it costs less to implement due to its simplicity in design. On the other hand, the case of continuous heating would avoid such undesirable temperature fluctuations. These results are also verified by experimental evaluations.