York S1-024-27632-001 0.4″ WC SPNO Close On Fall Pressure Switch

Description

York OEM Pressure Switch — S1-024-27632-001

The York S1-024-27632-001 is a factory OEM pressure switch engineered for use in York heating systems. Rated at 0.4″ water column (WC), this Single Pole Normally Open (SPNO) switch features a Close-on-Fall action, meaning its contacts close when the monitored pressure drops below the set point. This behavior is characteristic of draft inducer and combustion air pressure switches, which verify that the inducer motor is operating correctly and that the flue venting path is clear before allowing the burner to fire.

How It Works

During normal furnace operation, the inducer motor creates a negative pressure in the heat exchanger and flue system. The pressure switch monitors this negative pressure. If the pressure falls below the 0.4″ WC threshold — indicating proper draft — the SPNO contacts close, signaling the control board to proceed with ignition. If adequate negative pressure is not established (due to a blocked flue, failed inducer, or cracked heat exchanger), the switch remains open, locking out the burner as a critical safety measure.

Key Features

• OEM York replacement part — direct fit for compatible York furnace models
• Set point: 0.4″ water column (WC)
• Switch type: Single Pole Normally Open (SPNO)
• Action: Close on Fall — contacts close when pressure drops below set point
• Functions as a draft/inducer proving safety switch
• Prevents burner ignition if proper venting pressure is not confirmed
• Designed for reliable, long-term performance in residential and light commercial furnace applications

Application

• York brand furnaces and heating systems requiring OEM pressure switch replacement
• Draft inducer pressure monitoring and safety interlock circuits
• Direct OEM replacement to maintain system warranty and performance standards

Why Choose OEM?

Using a genuine York OEM pressure switch ensures precise calibration to your equipment’s factory specifications. Aftermarket substitutes may not match the exact set point or electrical ratings, potentially compromising system safety and efficiency. Always verify compatibility with your specific York model before installation.