OEM Lennox Dual Pressure Switch Assembly — 14T65

The genuine OEM Lennox 14T65 dual pressure switch assembly monitors negative and positive pressures created by the draft inducer to confirm your Lennox furnace is venting combustion gases safely before the burners are allowed to fire. The dual-switch design verifies proper airflow across two stages or pressure taps, acting as a key safety interlock that prevents operation when venting is blocked or the inducer is underperforming.

When this assembly fails, the furnace typically locks out on a pressure switch fault, won't advance past the inducer stage, short-cycles, or displays a pressure-related error code. Stuck contacts, a cracked switch housing, a clogged pressure tap, or a torn sensing hose are frequent culprits. A switch that stays open blocks ignition, while one stuck closed can allow unsafe firing.

An OEM Lennox 14T65 is calibrated to the exact trip and reset pressures your specific furnace model demands. Aftermarket switches with the wrong set points can nuisance-trip or, worse, fail to protect against dangerous venting conditions. Install the factory-matched assembly to keep your Lennox furnace operating safely and reliably.