Use a multimeter to measure the resistance across the leads

Standardized Fitment: Features a round form factor and integrated bracket for immediate mounting

repetitive ignition attempts followed by lockout

protecting the heat exchanger and evaporator coil from airflow-related issues

Carrier HH680300 Limit Switch THPU32HP7Y Use a multimeter to measureThe Carrier HH680300 is an essential OEM L140 15F 3 wire limit switch designed for precision thermal monitoring in residential and commercial furnaces. As a primary safety control switch, it features a fixed 140 degree Fahrenheit cut out setpoint and a 15 degree differential, ensuring the system interrupts operation effectively if the plenum temperature exceeds safe factory limits. This SPDT limit switch is engineered for high cycle reliability,