Heating by gas combustion is widespread in residential and industrial environments, through the use of different types of systems and plants. A relevant case is that of gas stoves, where the heat-radiating unit operates autonomously with local gas feeding and, eventually, electricity for an optional fan convector. A thermoelectric generator (TEG) can be integrated within this type of autonomous gas heater, for the local production of electric power, able to support electrical auxiliaries, where desired, without the need for any connection to the electrical grid. This approach can lead to easier installation and operation and, eventually, it increases the overall efficiency. Following the development work plan drawn in previous reports [1][2], a new prototype of an autonomous gas heater has been implemented through the integration of a TEG device with a simple and robust design, easily operated by the end user. A small amount of heat is withdrawn and converted into electricity by the TEG, providing self-sustaining operation and, moreover, powering new ancillary functions (e.g. fan convector) without extra electrical requirements and no need for an electrical connection.