Lochinvar & A.O. Smith 100318326 Pressure Switch

The Lochinvar & A.O. Smith 100318326 Pressure Switch is a critical safety component designed for precise water pressure monitoring in high-efficiency Noble Fire Combi Boilers and NKC series units. Engineering to detect low water pressure conditions, this switch acts as a primary fail-safe, preventing dry fire scenarios and potential heat exchanger damage by ensuring the burner circuit remains open unless sufficient system pressure is established. Built with a 1/2-inch NPT connection and brass housing, it provides superior corrosion resistance for long-term reliability in specialized heating and cooling applications. As a veteran-grade HVAC replacement part, it is compatible with NKC110, NKC150, and NKC199 models, as well as LK1200 boiler systems. This OEM water pressure switch ensures a direct fit, maintaining the boiler system safety standards and performance specifications required by licensed HVAC contractors for professional service and furnace repair.

• Universal Compatibility: Specifically engineered for the Lochinvar Noble NKC line (110, 150, 199) and A.O. Smith commercial water heating platforms.
• Rugged Construction: Features high-quality brass threading to prevent galling and ensure a leak-free seal in hydronic heating systems.
• System Protection: Rapidly identifies low pressure to interrupt the ignition cycle, safeguarding the combi boiler from catastrophic failure.
• Standardized Fit: 1/2" NPT fitting allows for straightforward integration into existing manifold or pipe configurations.

Which specific models does the 100318326 support?
This part is the primary water pressure switch for Lochinvar NKC110L/N/P, NKC150N/P, and NKC199L/N/P models, often found in Noble Fire Combi Boilers.

How do I troubleshoot a 100318326 sensor failure?
Technicians should check for continuity across the terminals when the system is pressurized. If the boiler control board reports a low water pressure fault despite verified gauge pressure, the switch's internal diaphragm may be fouled or the contacts stuck.

Is this switch field-adjustable?
No, this component comes with factory-calibrated set points designed to match the safety parameters of the NKC series and should not be tampered with in the field.

This item is not eligible for free shipping.

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.