Abstract: A gas-fired device for generating heat for a dwelling, comprising a vessel containing a liquid with an associated burner assembly for heating the liquid, an air-heat exchanger provided on a portion of the circumferential wall of the vessel, means for passing air through the heat exchanger for heating the air and a connection with means for passing the heated air to the room(s) to be heated, and a discharge for the combustion gases extending to the outside. On the remaining portion of the circumferential wall of said vessel a combustion gases-heat exchanger being mounted, so that heat is supplied to the vessel exclusively from the outside. Preferably a cooking assembly is provided above the vessel, and a condenser is mounted in the discharge channel for the combustion gases for pre-heating the air, a discharge conduit for the combustion gases from the cooking assembly being provided which leads also to said condenser.