Slant Fin 440-856-000 Pressure Switch

The Slant Fin 440-856-000 Pressure Switch is a critical safety component engineered specifically for high-efficiency draft inducer monitoring. This OEM Slant Fin replacement part is calibrated to a fixed .90" WC pressure setting, providing precise differential air pressure detection to ensure the combustion blower is moving sufficient air for safe burner operation. Designed for compatibility with the Slant Fin Victory II series, including models VHS-30, VHS-60, VHS-90, VHS-120, VHS-150, and VHS-180, this switch prevents the ignition sequence if flue venting or intake air is obstructed. The NS2-0312-00 pressure switch features a high-sensitivity internal diaphragm and a rugged housing built to withstand the thermal cycling typical of gas-fired hydronic boilers. When troubleshooting boiler lockout codes or inducer circuit failures, verifying the 0.90" WC trip point with a manometer is essential before swapping this HVAC draft pressure switch. Its compact footprint and standardized spade terminals facilitate straightforward integration into the existing control loop.

• Factory Calibrated Precision: Fixed 0.90" WC setpoint ensures reliable furnace and boiler safety circuit operation without the need for field adjustment.
• Extensive Model Compatibility: Drop-in OEM part 440-856-000 for the complete Slant Fin Victory II boiler lineup (VHS-30 through VHS-180).
• Inducer Fan Verification: Continuously monitors the pressure differential produced by the draft inducer to confirm proper venting.
• Durable Construction: Engineered with a high-grade diaphragm and robust electrical contacts to handle frequent cycling in residential heating applications.

What causes a .90" WC pressure switch to fail?
Mechanical failure is often caused by a ruptured diaphragm or moisture buildup in the sensing lines. However, frequent "Open Pressure Switch" errors are usually symptomatic of a restricted vent, a failing inducer motor, or a clogged heat exchanger rather than a faulty Slant Fin 440-856-000 switch itself.

Can I use this as a universal HVAC pressure switch?
No, this is a brand-specific OEM replacement. Pressure switches must match the exact WC rating (0.90") and contact configuration (typically SPST) of the original component to maintain the gas valve safety interlock.

Does this switch handle high-voltage inducer circuits?
This switch is designed for the 24V pilot circuit. It acts as a safety gate for the control board to verify airflow before energizing the hot surface igniter or spark ignition system.

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.