Trane CNT3671 Pressure Switch

The Trane CNT3671 Pressure Switch is an essential OEM replacement part designed for precise airflow monitoring in gas furnace and air handler applications. This .20" WC SPST air pressure switch functions as a critical safety limit, ensuring the inducer motor establishes proper static pressure before the ignition sequence initiates. Rated for a single-pole single-throw (SPST) configuration, the CNT3671 features snap-acting contacts and is engineered for high-cycle reliability in residential and commercial split systems. It serves as the direct factory authorized replacement for legacy part numbers CNT03671 and SWT1858. Built to withstand operating temperatures from -40°F upward, this switch maintains system integrity by detecting venting blockages or inducer failures. For field technicians, confirming the 0.20 inch water column set point is vital for maintaining the manufacturer's specified combustion safety parameters and preventing nuisance trips or no-heat calls in Trane and American Standard equipment.

• OEM Precision: Genuine Trane replacement part ensures exact calibration to 0.20" WC for factory-spec safety performance.
• Enhanced Compatibility: Direct drop-in replacement for CNT03671 and SWT1858, reducing time on the job site.
• Robust Construction: Features snap-acting contacts and 1/4" quick-connect terminals for secure electrical continuity and long service life.
• System Safety: Effectively monitors inducer motor performance to prevent hazardous furnace operation under restricted venting conditions.

How do I know if my Trane pressure switch is failing?
Technicians typically look for a "3-flash" or "2-flash" error code on the integrated furnace control board, which often indicates the furnace pressure switch failed to close or stayed open during the inducer startup cycle.

Can I use a higher WC rated switch as a substitute?
No. Using a switch with a different inches water column (WC) rating can compromise safe combustion or cause the furnace to fail to ignite. Always match the CNT3671 rating of .20" WC for this specific application.

What causes a pressure switch to stay open?
Common culprits include a failing inducer motor, cracked pressure switch tubing, a restricted flue pipe, or a clogged condensate drain in high-efficiency models.

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.