OEM Lennox Dual Pressure Switch Assembly — 14T64

The genuine OEM Lennox 14T64 dual pressure switch assembly is a safety control that verifies proper draft and venting before and during furnace operation. It monitors negative pressure created by the inducer motor and confirms the flue is clear, allowing the ignition sequence to proceed only when it's safe to fire the burners.

Common failure symptoms: A faulty pressure switch commonly causes ignition lockouts, a furnace that won't light, or repeated short-cycling. You may see a pressure-switch fault code, hear the inducer run without the burners igniting, or find the unit stuck in a wait-and-retry loop — often the result of a stuck switch, cracked hose port, or drifted setpoint.

Why OEM matters: Pressure switches are calibrated to a specific trip point matched to your furnace's inducer and venting design. The genuine 14T64 carries the correct pressure rating and port configuration, so it trips exactly when your Lennox system requires. A mismatched aftermarket switch can allow unsafe operation or cause nuisance lockouts, making the OEM part the reliable choice for this safety-critical control.