Abstract: An air flow control and routing apparatus for attaching to a water heater, to restrict entry of floor-level gases into the water heater, includes a substantially annular skirt for surrounding a base portion of a water heater. Preferably, the skirt has a closable pilot access door formed therein. The apparatus also includes at least one air intake tube attached to the annular skirt for transporting inlet air therethrough, the air intake tube having an elevated inlet, relative to the skirt, when the apparatus is in an installed orientation thereof. In this first embodiment of the invention, the apparatus is constructed and arranged to feed indoor air, from a portion of a room above floor level, to a water heater combustion chamber, located at the lower end of a water heater, when installed thereon. The invention also encompasses a water heater having the air flow control and routing apparatus installed thereon, and a method of routing inlet air into a water heater using the described apparatus.