Electronically

The impedance-protected coil provides thermal protection during continuous operation or stall conditions

Optimized Flame Pattern: Precise venturi design promotes stable combustion efficiency and reduces call-backs for lifting or yellowing flames

Vibration-Resistant Solenoid: Built to handle the rapid cycling requirements of modern condensing boilers

Carrier HH18HA304 Limit Switch R-410A ElectronicallyThe Carrier HH18HA304 Limit Switch is a critical safety component designed for precise thermal monitoring in residential gas furnaces and air handlers. Engineered as a L55F 22 furnace limit switch, this normally closed (NC) sensor features a 55 degree Fahrenheit fixed temperature trip point with a 22 degree differential for automatic reset. This OEM replacement ensures the furnace high limit switch maintains the heat exchanger within safe operating