Lennox 59W40 Proving Switch 324846-701 Whether you are servicing a

Whether you are servicing a rooftop unit or an indoor furnace

you can replace the diaphragm and O-rings while the valve body remains in the pipeline

Enhanced System Efficiency: Prevents water from pooling in the secondary heat exchanger area

featuring an integrated time delay relay that optimizes airflow by managing the fan motor’s post-purge cycle

120V line voltage control engineered for high-capacity commercial and industrial heating applications

Lennox 59W40 Proving Switch 324846-701 Whether you are servicing aThe 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