OEM Lennox Gas Valve — 18M65

The genuine OEM Lennox 18M65 gas valve regulates the flow of natural gas or propane to the burners in your Lennox furnace. Working with the ignition control and safety circuit, it opens to admit fuel only when a call for heat and proof of ignition are present, and it maintains the correct manifold pressure for clean, efficient combustion. As a safety-critical component, it also shuts off fuel instantly when the control board removes the signal.

A failing 18M65 commonly causes no-heat conditions, burners that won't light or light weakly, delayed ignition or a "whoomph" on start-up, inconsistent flame, or a furnace that locks out after failed ignition attempts. A gas valve that chatters, leaks, or won't hold the correct manifold pressure is a clear sign of internal wear.

Using the OEM Lennox 18M65 is essential because gas valves are matched to your furnace's fuel type, capacity, and control voltage, and are safety-listed for that application. An incorrect or unrated valve can create combustion problems or serious safety hazards. This factory-matched valve ensures proper fuel metering, correct manifold pressure, and reliable safety shut-off for your Lennox equipment. Installation should always be performed by a qualified technician.