Lochinvar & A.O. Smith 100277772 Pressure Switch 318973-401 Industrial Protection: The NEMA 4

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

Replacing the diaphragm and seat with this kit typically resolves these issues

ensuring fail-safe operation during power interruptions

reducing labor time and system downtime

Lochinvar & A.O. Smith 100277772 Pressure Switch 318973-401 Industrial Protection: The NEMA 4The 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