this SPDT air pressure sensing switch is factory-calibrated to operate on a pressure rise at 0

It serves as a direct fit for various Knight XL models and select Armor water heaters

Built for demanding commercial environments

this genuine HVAC furnace control board ensures the unit maintains factory-spec operational parameters

Optimized Performance: Facilitates reliable flame rectification

Lochinvar & A.O. Smith 100288429 Switch 319825-402 this SPDT air pressure sensingThe Lochinvar & A. O. Smith 100288429 Switch is a critical safety component designed for precise air pressure sensing in high efficiency heating systems. This OEM replacement part is factory calibrated to a 3. 90" water column (WC) set point, serving as a primary air proving switch to ensure the blower motor is moving sufficient combustion air before the ignition sequence begins. Engineered for compatibility with specific Lochinvar boilers and A. O.