York S1-1PS0309 Pressure Switch

The York S1-1PS0309 Pressure Switch is an OEM-specified safety component engineered for high-altitude gas furnace installations. This SPST pressure switch is calibrated to a fixed setpoint of -0.90" WC (water column), ensuring the inducer motor maintains the critical vacuum thresholds necessary for safe flue gas venting in low-density air environments. Designed for precise atmospheric monitoring, this switch replaces standard units to prevent nuisance tripping and operational failures at elevations up to 10,000 feet. The Source1 S1-1PS0309 features a reliable 1/4-inch barbed connection for secure pneumatic tubing attachment and provides a direct interface with the ignition control module to confirm proper combustion airflow before the burner cycle initiates.

Key Benefits:

• Optimized High-Altitude Performance: Specifically calibrated for heating equipment operating in thin air conditions where standard furnace pressure switches may fail.
• Direct OEM Replacement: Ensures exact fit and function for York, Coleman, and Luxaire units, maintaining the original engineering specifications of the appliance.
• HVAC System Safety: Actively monitors draft pressure to prevent the operation of the gas valve under hazardous venting conditions.
• Rugged SPST Construction: Single-pole single-throw electrical configuration provides a durable, heat-resistant switching mechanism for high-cycle industrial use.
• Ease of Installation: Features a standard 1/4" barbed connection and multi-position mounting bracket for fast replacement in the field.

Common Questions:

When should I use a high-altitude pressure switch vs. a standard switch?
Standard switches are calibrated for sea-level air density. If a furnace is installed at elevations typically above 2,000 to 5,000 feet, the lower air density provides less resistance, making the -0.90" pf pressure switch necessary to ensure the inducer motor can successfully close the circuit.

Will this switch fix a "Pressure Switch Stuck Open" fault code?
While this S1-1PS0309 switch is a common solution for fault codes, technicians should first verify the heat exchanger integrity, flue pipe obstructions, and inducer motor RPM. If those parameters are within spec, the internal diaphragm of the switch may be ruptured or fatigued.

Is this switch compatible with multi-stage furnaces?
This specific model is typically utilized as a safety limit for specific York furnace models. Always cross-reference the part number and WC rating on the existing switch's label to ensure compatibility with your specific HVAC unit’s manifold pressure 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.