If the flame sensor detects a loss of signal during the cycle

the start circuit is cleanly disconnected to prevent winding overhead or damage

ensuring broad compatibility across various commercial and heavy-duty residential boilers and furnaces

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

providing a consistent capillary gap for reliable brazing with Sil-Fos or comparable alloys

Carrier HH680300 Limit Switch THPU32HP7Y If the flame sensor detectsThe 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,