Lochinvar & A.O. Smith 100208406 Switch

For service technicians and mechanical contractors maintaining high-efficiency boilers, the Lochinvar & A.O. Smith 100208406 Low Air Switch is a critical safety component designed to ensure proper combustion air pressure. This OEM pressure switch, also referenced by part numbers PRS2707 and PRS2707K, operates with a precise 2.48" WC setpoint to monitor the pressure differential across the blower assembly. If it detects a drop in air volume or a blocked flue condition, it immediately breaks the 24V control circuit, preventing the ignition sequence and protecting the heat exchanger from improper soot accumulation or thermal stress. Designed for seamless integration into Lochinvar Knight and Armor water heaters, this low air pressure switch features a robust internal diaphragm and silver contacts for long-term reliability in demanding condensing boiler applications. When troubleshooting APS open error codes or blower proving issues, verified 100208406 boiler parts ensure the system returns to its factory-spec performance without the risks associated with universal after-market alternatives.

• Direct OEM Compatibility: Engineered specifically for Lochinvar and A.O. Smith units, ensuring the 2.48" WC pressure setting matches the original safety parameters.
• Enhanced Failsafe Protection: Effectively detects blocked air intakes or failing blowers to prevent hazardous operating conditions.
• Simplified Field Replacement: Features standard spade terminal connections and a compact housing for quick installation in tight cabinets.
• High-Precision Monitoring: Maintains tight tolerances to avoid nuisance tripping caused by minor atmospheric fluctuations.

• Why is my boiler showing an 'APS Open' lock-out? This typically signifies the 100208406 switch has detected insufficient air flow; check for vent obstructions, debris in the intake screen, or a cracked silicone reference tube before replacing the switch.
• Can I use a PRS2707 in place of a 100208406? Yes, the PRS2707 and PRS2707K are identical manufacturer cross-references for the same technical specification.
• How do I verify if the low air pressure switch is faulty? Use a manometer to measure the actual pressure differential; if the WC level is above the setpoint but the switch remains electrically open, a replacement is necessary.

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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.