though internal components should be protected from direct moisture or heavy vibration

check the spark gap distance against factory specs

or blocked return air grilles

If the vacuum breaker is constantly weeping from the atmospheric vent or fails to close during pressurized flow

maximizing thermal conductivity

Johnson Controls P74FA-1 Pressure Control Els PW 29614 though internal components should beThe Johnson Controls P74FA 1 is a professional grade differential pressure control designed for precise monitoring of pressure variations between two sensing points. This heavy duty SPDT snap acting switch is a standard for contractors managing chillers, water cooled condensers, and heating coils where proof of flow is critical for system protection. Engineered with durable brass bellows, the unit handles non corrosive refrigerants, air, and liquids