York S1-7142-3091 Limit Switch What is the primary function

What is the primary function of this transition piece

Does this unit require an external power source

Are the threads standard NPT

For technicians performing HVAC system troubleshooting or routine safety inspections

York S1-7142-3091 Limit Switch What is the primary functionThe York S1 7142 3091 Limit Switch is a critical safety component designed for precise thermal regulation in York, Coleman, and Luxaire gas furnaces. This SPST automatic reset limit switch functions with a 110 150F temperature range, opening the circuit at 150F and automatically closing at 110F to prevent heat exchanger overheating. As a direct OEM replacement for 626245 and 626246, it maintains factory specifications for high limit protection.