IMAGE COMING SOON
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The genuine OEM Lennox 75M22 pressure switch is a critical safety control that verifies proper airflow and venting in your furnace before allowing ignition. Connected to the draft inducer by a rubber hose, it senses negative pressure and closes its contacts only when adequate combustion airflow is confirmed. This factory-calibrated switch is set to the precise trip point required by your Lennox furnace, protecting against dangerous flue blockages and inadequate venting.
Common failure symptoms: When the 75M22 fails or trips, the furnace typically will not light and often locks out on a fault code. Watch for the draft inducer running but no ignition, short cycling, a furnace that starts then shuts down, or blower-only operation with no heat. Cracked hoses, condensate blockage, or worn contacts are frequent causes.
Why OEM matters: Pressure switches are calibrated to a specific "inches of water column" set point. A generic replacement with the wrong rating can nuisance-trip or, worse, allow the furnace to fire under unsafe venting conditions. The OEM Lennox 75M22 delivers the exact factory calibration and connection fit your system was designed around, restoring safe, reliable furnace operation.