This snap-action safety device utilizes an open-on-rise switch action to interrupt the electrical circuit when the ambient temperature reaches a fixed open temperature of 190 degrees F

ensuring stable capacitance under varying thermal loads

while the two opposing ends are 1/2-inch SAE Male Flare

000 AFC pressure-sensitive interrupter

York S1-024-21678-700 Relay This snap-action safety device utilizesThe York S1 024 21678 700 is an OEM 24V SPDT Relay designed for heavy duty switching in residential and commercial HVAC control systems. This component serves as the direct 024 21678 000 replacement, ensuring seamless integration into existing control boards without requiring circuit modifications. Engineered with a 24VAC 50 60Hz coil, this Single Pole Double Throw relay provides the necessary electrical isolation between low voltage thermostat