York S1-024-35270-000 Pressure Switch

The York S1-024-35270-000 Pressure Switch is a critical safety component designed for specific York, Luxaire, and Coleman furnace models. Operating as a SPNO (Single Pole Normally Open) switch, it is calibrated to a -.45" WC set point, closing on a fall in pressure. This HVAC inducer pressure switch ensures the draft inducer motor is moving sufficient air through the heat exchanger before the ignition sequence begins, preventing hazardous combustion conditions. As a direct OEM replacement part, it maintains the precise pressure tolerances required by the manufacturer, ensuring system reliability and preventing nuisance trips or furnace pressure switch lockout issues.

When diagnosing a furnace not igniting, checking the 024-35270-000 pressure switch for proper continuity and diaphragm integrity is standard procedure. This component features a robust housing and high-quality electrical contacts to withstand the thermal cycling and vibration common in residential heating applications. Proper installation requires verifying the vacuum hose connection and ensuring the venting system is clear of obstructions that could impact the pressure differential across the heat exchanger.

Key Technical Benefits

• OEM Precision: Guaranteed compatibility with York S1-024-35270-000 specifications for accurate pressure sensing.
• SPNO Configuration: Single Pole Normally Open design ensures the circuit only completes when the required -.45" WC vacuum is achieved.
• System Protection: Prevents burner operation during inducer motor failure or flue blockage.
• Direct Fit: Replaces outdated or failed HVAC pressure switches without the need for modification or field calibration.

Common Technical Questions

Does this switch replace a different WC rating?
No, pressure switches are calibrated to specific furnace performance curves. Using a switch with a different water column (WC) rating than the -.45" specified can lead to unsafe operation or frequent system faults.

What causes a pressure switch to fail to close?
Common causes include a failing inducer motor, cracked vacuum tubing, a restricted chimney or vent pipe, or a ruptured internal diaphragm within the switch itself.

Can this be used on high-efficiency condensing furnaces?
This switch is designed for specific furnace platforms. Always verify the part number against your model’s parts list to ensure the logic and set point match the OEM requirements.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.