Abstract: A new accessory for combustion devices such as swimming pool heaters for preventing downdrafting and allowing for proper ventilation. The inventive device includes a vertically disposed pipe extending upwardly from a combustion device. The pipe has a generally cylindrical configuration. The pipe has an open upper end. The open upper end has a plurality of circumferentially spaced brackets extending upwardly therefrom. Upper ends of the brackets have an upper pipe extending upwardly therefrom. The upper pipe has open upper and lower ends. The open upper end of the upper pipe has a plurality of circumferentially spaced brackets extending outwardly therefrom. A draft hood is secured to the brackets of the vertically disposed pipe downwardly of the upper ends thereof. A vent cap is removably secured to upper ends of the brackets of the upper pipe.