Lochinvar & A.O. Smith 100109962 Switch

The Lochinvar and A.O. Smith 100109962 Blower Prover Switch is a critical safety component designed to verify adequate airflow within the combustion chamber before ignition occurs. This differential pressure switch serves as the current OEM replacement part for legacy numbers 9004586215 and NS2-0097-00. When the inducer motor engages, this switch monitors the pressure drop across the venturi or heat exchanger, ensuring the system can safely vent flue gases. If the pressure switch fails to close due to a blocked flue or failing motor, the ignition control module will lockout to prevent unsafe operation. Engineered for precise setpoint calibration, the 100109962 maintains system integrity in high-efficiency commercial water heaters and boilers. Utilizing high-grade silicone diaphragms and corrosion-resistant electrical contacts, this HVAC pressure switch ensures reliable draft verification and long-term diagnostic accuracy for professional mechanical contractors.

• Direct OEM Compatibility: Engineered specifically for Lochinvar and A.O. Smith units, replacing 9004586215 and NS2-0097-00 seamlessly.
• Critical Safety Integration: Prevents combustion cycles in the event of improper venting or inducer blower failure.
• Accurate Pressure Sensing: Calibrated to detect minute changes in static pressure for consistent system performance.
• Durable Construction: Built to withstand the high-temperature environments found in commercial mechanical rooms.

What causes a blower prover switch to fail?
Failure is often caused by moisture buildup in the sensing tubes, a ruptured internal diaphragm, or carbon deposits hindering the mechanical movement of the switch.

Can I use a universal pressure switch instead of the 100109962?
It is not recommended. This part has a specific WC (Water Column) trip point calibrated for the blower curves of specific A.O. Smith and Lochinvar models to ensure safety protocols are met.

How do I troubleshoot a pressure switch lockout?
Check for obstructions in the venting, inspect the vacuum tubing for cracks, and use a manometer to verify if the inducer motor is pulling the required vacuum to close the circuit.

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.