York S1-025-54125-000 Air Pressure Switch 0 IWC On Fall

Description

York OEM Air Pressure Switch — S1-025-54125-000

The York S1-025-54125-000 is a factory-authorized OEM replacement air pressure switch engineered for use in York heating and cooling systems. Designed with a 0 IWC (inches water column) set point and an “On Fall” switching action, this switch monitors negative pressure within the system to verify proper inducer or blower operation before allowing the heating sequence to proceed — a critical safety function in modern furnaces and air handlers.

How It Works

Air pressure switches in HVAC systems are wired into the control circuit to confirm that the draft inducer motor has created adequate negative pressure in the heat exchanger and flue. With an “On Fall” action, this switch closes its contacts when pressure drops to or below the 0 IWC set point, signaling the control board that safe operating conditions exist. If the required pressure is not achieved — due to a blocked flue, failed inducer, or cracked pressure tubing — the switch remains open and prevents ignition, protecting both the equipment and the occupants.

Key Features

• OEM York replacement part — ensures proper fit and function in compatible York equipment
• Set point: 0 IWC (inches water column)
• Switching action: On Fall (contacts close on pressure decrease)
• Monitors inducer/blower operation for safe furnace sequencing
• Helps prevent ignition under unsafe or improper draft conditions
• Direct drop-in replacement to minimize downtime on service calls

Application

This pressure switch is intended for use in York residential and light commercial furnaces and air handlers that require a 0 IWC On Fall pressure switch. Always verify compatibility with the specific York model being serviced before installation.

Why Choose OEM Parts?

Using genuine York OEM replacement components ensures the part meets original design specifications, maintains equipment warranty compliance, and delivers reliable long-term performance. Aftermarket substitutes may not replicate exact set points or switching characteristics, potentially compromising system safety and efficiency.