York S1-024-35282-000 -.4/-.9″ SPNO Close On Fall Pressure Switch

Description

York S1-024-35282-000 SPNO Close On Fall Pressure Switch

This York OEM pressure switch (S1-024-35282-000) is engineered for reliable combustion airflow and draft proving in York heating systems. With a Single Pole Normally Open (SPNO) configuration and a “Close on Fall” action, this switch monitors negative pressure and closes the circuit when pressure drops to the specified setpoint — a critical safety function that confirms proper inducer or draft blower operation before allowing ignition to proceed.

Key Features

• OEM York replacement part — ensures precise fit and performance in compatible York systems
• SPNO (Single Pole Normally Open) switching configuration
• Close on Fall action — switch closes when monitored pressure falls to setpoint
• Dual setpoints: -.4″ and -.9″ water column (WC)
• Designed for draft proving and combustion air safety applications
• Helps prevent ignition in the absence of proper airflow, protecting equipment and occupants
• Direct OEM replacement for simplified installation and maintenance

Application

This pressure switch is a critical safety component in York furnaces and air handlers. It monitors the negative pressure created by the inducer blower during the pre-purge cycle. If the required pressure differential is not achieved — indicating a blocked flue, failed inducer motor, or other airflow issue — the switch remains open, preventing the ignition sequence from initiating. This safeguards against unsafe combustion conditions and protects the heat exchanger from damage.

Specifications

• SKU: S1-024-35282-000
• Brand: York
• Switch Type: SPNO (Single Pole Normally Open)
• Action: Close on Fall
• Setpoints: -.4″ / -.9″ WC (water column)
• Application: Draft / combustion airflow proving