the switch must be installed vertically according to manufacturer specifications

the Macon N10857 horizontal angle body is intended for two-pipe steam systems or hot water applications

Johnstone Supply

a KP5 or KP15 series switch is typically recommended

and FC9M100 furnace models

Lennox 10U93 Pressure Switch 321142-301 the switch must be installedThe Lennox 10U93 Pressure Switch is a critical OEM safety component designed for precise airflow monitoring in Lennox, Armstrong, and Ducane furnace systems. This . 65" WC SPST pressure switch functions by validating that the inducer motor is creating sufficient draft to safely vent combustion gases before allowing the ignition sequence to proceed. As a Single Pole Single Throw (SPST) normally open switch, it provides a reliable electrical signal to