Utica-Dunkirk 18682 Pressure Switch

The Utica-Dunkirk 18682 Pressure Switch is a critical safety component engineered for precise combustion air proving in high-efficiency boilers and furnaces. Rated at .60" WC (Water Column), this normally open (NO) switch is factory-calibrated to ensure the inducer fan generates sufficient static pressure before allowing the ignition sequence to proceed. As a veteran technician knows, maintaining the correct differential pressure is non-negotiable for preventing the buildup of flue gases and ensuring safe, reliable operation in residential and commercial HVAC systems.

Constructed with a high-durability diaphragm and a robust housing, the OEM replacement 18682 is designed to withstand the thermal stress and moisture common in condensing heating units. This switch serves as the primary safeguard against blocked vent conditions or inducer motor failure. By monitoring the vacuum levels within the collector box or vent pipe, it provides the control board with the exact feedback needed to energize the gas valve. When troubleshooting short-cycling or no-heat calls, verifying the .60" WC setpoint with a digital manometer is a standard best practice for any contractor servicing Utica or Dunkirk equipment.

• Precise Actuation: Calibrated specifically to a .60-inch WC setpoint for exact airflow verification.
• OEM Compatibility: Authentic Utica-Dunkirk part ensures perfect fitment and eliminates the risks associated with generic universal switches.
• Enhanced Safety: Acts as a failsafe to prevent burner operation during restricted venting or manifold pressure issues.
• Durable Engineering: Designed to resist fatigue and environmental factors in demanding condensing boiler environments.

What causes a "Pressure Switch Open" fault code?
This is typically caused by a blocked vent, a failing inducer motor, water in the sensing tubes, or a ruptured internal diaphragm within the switch itself.

Can I use a higher or lower WC rated switch as a substitute?
No. Pressure switches must match the manufacturer specifications exactly. Using the wrong setpoint can lead to dangerous incomplete combustion or frequent lockouts.

How do I verify if the 18682 switch is functional?
Check for 24V across the terminals while the inducer is running. If the inducer is pulling at least .60" WC and the switch remains open, the internal contacts are likely fouled or stuck.

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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.