Simplified Installation: Designed as a bolt-on end bell module

two stainless steel diaphragms

and visible external leakage through the bonnet seal

For UDAP/UDAS models

Lochinvar & A.O. Smith 100276842 Pressure Switch 320788-704 Simplified Installation: Designed as aThe Lochinvar & A. O. Smith 100276842 Pressure Switch is a critical safety component designed to monitor combustion blower performance and ensure proper venting pressure within high efficiency commercial water heaters and boilers. This OEM air pressure switch acts as a fail safe, preventing ignition if the inducer motor fails to establish the correct differential pressure. As the direct 100166151 replacement part, this switch is engineered for high