42" air pressure switch (1

cutting or kinking the tube will destroy the sensing bulb functionality and render the part useless

and Marley Engineered Products electric heating installations

Smith and Lochinvar technical assemblies

Installing a blade with a different pitch than the specified 38 degrees can lead to motor overloading or insufficient airflow

Lennox 97J69 Pressure Switch 328140-751 42" air pressure switch (1The Lennox 97J69 Pressure Switch is a critical safety component designed for specific Lennox furnace models to monitor induction blower performance and flue venting integrated within the combustion circuit. This SPST (Single Pole Single Throw) vacuum switch is factory calibrated to a . 85" WC (Water Column) set point, ensuring the system only initiates the ignition sequence when proper static pressure is established. Featuring a standard 1 4" barb