Use a multimeter to check for continuity across the SPST terminals and a manometer to verify the switch closes at the manufacturer's specified pressure rating

1-watt power profile and 1/2 inch NPT conduit connections

Corrosion-Resistant Housing: The Emerson Alco moisture indicator features a robust brass body to withstand harsh mechanical room environments

using a different rating can lead to unsafe combustion or nuisance shutdowns

White-Rodgers 1A11-2 Thermostat Els PW 17895 Use a multimeter to checkWhite Rodgers 1A11 2 36 90F SPDT Line V Fan Coil Non Programmable Tstat Line Voltage, SPDT Thermostat, 36F To 90F Range, Lead Wires, System Switch: Heat Off Cool, Fan Switch: Low Med High. For Use With Fan Coil Units