The gas-fired heating apparatus, especially a water heater, has a combustion chamber (2a); an atmospheric gas burner (5) within the combustion chamber (2a); a combustion gas/air supply system (18) having an intake device (16) for combustion gas and primary air to be mixed with the combustion gas, which is arranged outside of the combustion chamber, and an oscillation-damping air supply chamber (11) provided with at least one air inlet (12), which is connected upstream to the intake device (16) and is constructed as a Helmholtz resonator to reduce noise and stabilize combustion. To provide sufficient primary air under adverse spatial conditions the air supply chamber (11) has an exterior wall (11′) and a pattern (13, 14) of perforations in the exterior wall, which are formed as additional air inlets for additional supply of the primary air.