This electronic fail-safe actuator delivers 112 lbf of linear force

or a noticeable drop in pressure regulation efficiency

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

dry control air to prevent component failure

It matches the electrical specifications and mounting dimensions required for a direct swap

Lennox 59W40 Proving Switch 320720-756 This electronic fail-safe actuator deliversThe 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