In this study, thermophotovoltaic (TPV) system components are examined and introduced, and theoretically, it is given information about the applicability of the system in a combi boiler. The latest developments in the components of the TPV system, heat source, emitter, filter and TPV cell, are explained. Also, the study state how the TPV system should be integrated into a combi boiler. It is estimated that the TPV system integrated into the combi boiler can produce 36.96 kWh per month in the case that it has 2% electrical efficiency. The study is stated that the higher TPV system electric power output can be achieved if the emitter, the filter and the TPV cell are matched in harmony with each other in the combi boiler, the distances of these components and the emitter-filter dimensions are arranged. Thus, a standard family in Turkey can be supplied a certain amount of monthly energy demand. Also, it is explained in the study the issues that should be taken into consideration when this system is integrated into the combi boiler.