Lochinvar & A.O. Smith 100109935 Flue Switch

Maintain the exhaust integrity and operational safety of your high-efficiency heating systems with the Lochinvar & A.O. Smith 100109935 Flue Switch. As a critical safety component, this blocked flue pressure switch is engineered to detect vent obstructions and immediately signal the control board to terminate the ignition cycle, preventing hazardous flue gas recirculation. This genuine OEM part is the designated 100109935 replacement for 9004550215, featuring the exact RSS-498-026 specifications required for consistent set-point reliability in Lochinvar boilers and A.O. Smith water heaters. Designed for professional installation, this HVAC exhaust safety switch ensures your commercial or residential units stay within precise factory pressure tolerances. Whether you are performing routine maintenance or troubleshooting a "blocked outlet" fault code, utilizing this updated OEM heating part ensures seamless mechanical compatibility and restores the system to its original performance standards without the risks associated with generic alternatives.

• Direct OEM Replacement: Optimized for use as the direct successor to part number 9004550215, ensuring a drop-in fit.
• Critical Safety Logic: Precisely monitors vent backpressure to prevent the operation of the burner during flue blockages.
• Broad Compatibility: Validated for a wide range of A.O. Smith and Lochinvar high-efficiency condensing units.
• System Protection: Helps prevent long-term damage to internal components by maintaining proper venting parameters.

How do I know if the 100109935 flue switch is faulty?
Technicians typically check for a specific fault code on the UIM display related to a "Blocked Outlet" or "Flue Clogged." Ensure the venting is clear first; if the vent is unobstructed but the switch fails to close during the blower cycle, the switch may require replacement.

Is the 100109935 compatible with older 9004550215 models?
Yes, the 100109935 is the official updated version specifically designed to replace the 9004550215 and the 193364 part numbers.

Can I test this switch with a manometer?
Professional contractors should use a manometer to verify the actual vent pressure against the switch's specific set-point to determine if the switch is tripping prematurely or failing to activate.

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.