Lochinvar & A.O. Smith 100277772 Pressure Switch 318973-401 Reliable Combustion: Provides high-intensity ignition

Reliable Combustion: Provides high-intensity ignition to prevent delayed ignition or lockout codes

Its rugged construction is built to withstand the thermal cycling typical of high-demand HVAC heating systems

Industrial Protection: The NEMA 4 rated watertight enclosure allows for safe operation in washdown or outdoor environments

The integrated spring return actuator ensures a reliable fail-safe position during power loss

Simplified Wiring: Includes a built-in transformer and coded screw terminals for efficient field integration

Lochinvar & A.O. Smith 100277772 Pressure Switch 318973-401 Reliable Combustion: Provides high-intensity ignitionThe Lochinvar & A. O. Smith 100277772 Pressure Switch is a critical safety component engineered for high altitude applications in Crest FBN and FBL heating boilers. This F9 high altitude air pressure switch is factory calibrated with a 4. 1 in WC set point to monitor combustion chamber pressure accurately in thinned atmospheres. It serves as a proving switch, ensuring the combustion air blower provides sufficient flow for a clean, safe burn before the