or a noticeable drop in pressure regulation efficiency

5-inch NPT ports without significant pressure drops

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

Keep this essential furnace limit control in your truck to resolve high-limit trips efficiently and restore safe operation to your client's equipment

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

Lennox 59W40 Proving Switch 320720-756 or a noticeable drop inThe 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