Secure Connections: 1/4" SAE flare fittings provide a reliable seal and simplified field replacement

the ACM1400M-108 is a reliable solution for improving indoor air quality without stressing the blower motor

dry control air to prevent component failure

the K15DA-48 is a direct replacement for the K15DA-48H

5-inch NPT ports without significant pressure drops

Lennox 59W40 Proving Switch 320720-756 Secure Connections: 1/4" SAE flareThe Lennox 59W40 Blower Proving Switch is a critical safety component designed for specific Lennox furnace models and air handling units. This negative pressure switch is calibrated to a precise . 15" WC setpoint, ensuring the inducer motor or blower assembly is generating sufficient draft before allowing the ignition sequence to proceed. As a genuine Lennox replacement part, the 59W40 ensures seamless integration with the existing control board