w.c.) CFM Size 4 Size 5 Modulating Gas System The second system, the Maxitrol modulating gas system, consists of a temperature selector dial, a discharge air sensor, an amplifier, and a Maxitrol 14 modulating gas valve. The two types of Maxitrol systems used are the Maxitrol Amplifier14 series or the Maxitrol 44 series. The Maxitrol 14 utilizes a discharge air sensor and modulates the Maxitrol gas valve to provide discharge air to match the selected temperature on the temperature selector. The M