York S1-024-34685-000 Pressure Switch

The York S1-024-34685-000 Pressure Switch is an essential OEM safety component engineered for precise monitoring of the inducer draft and combustion venting cycles. This normally open (N/O) pressure switch is factory-calibrated with a multi-stage setpoint configuration of .75/1.1/.4 in. WC (Inches Water Column). By verifying that the draft inducer motor is moving a sufficient volume of air to safely exhaust combustion gases, this furnace air pressure switch prevents ignition under hazardous conditions such as blocked flues, failing inducer motors, or restricted heat exchangers.

Designed specifically for York HVAC systems and Johnson Controls family equipment, this genuine Source 1 replacement part ensures your residential or light commercial furnace maintains exact pressure sensing accuracy. In the field, technicians rely on this OEM York pressure switch to resolve common furnace fault codes, specifically those indicating a failure to prove the draft (often 3 red flashes on many York control boards). Replacing a drifted or failed diaphragm with this factory-authorized part restores reliable sequencing and protects the heat exchanger from improper air-to-fuel ratios.

Key Technical Benefits:

• OEM Calibration: Precise .75 / 1.1 / .4 in. WC ratings ensure the switch closes and remains closed only when proper negative pressure is established.
• Normally Open (N/O) Logic: Integrated safety design prevents startup if the switch is stuck in a closed position at the beginning of the cycle.
• Wide Compatibility: Direct fit for York, Coleman, and Luxaire furnaces; specifically verified for models like the PV9B12N080DH11A.
• Industrial Durability: Engineered to withstand the rapid thermal cycling and high-moisture environments typical of 80% and high-efficiency gas furnaces.
• Enhanced Safety: Acts as the primary safeguard against carbon monoxide buildup by preventing the gas valve from opening without a confirmed draft.

Common Questions & Troubleshooting:

How do I know if the S1-024-34685-000 is failing?
If the inducer motor runs but the igniter never glows, use a manometer to check the draft. If the suction exceeds 1.1 in. WC but the switch terminals show 24V (meaning the circuit remains open), the internal diaphragm or contacts have likely failed. Always check for clogged vacuum ports or cracked tubing before replacement.

What do the three different pressure ratings represent?
These values correspond to the specific pressure points for opening, closing, and the operating differential (hysteresis). Maintaining the exact OEM specifications is critical; using a universal switch with different ratings can lead to nuisance shutdowns or unsafe operation during high-wind or cold-start conditions.

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.