Precise Safety Calibration: Maintains a strict 120°F to 140°F operating range to protect the gas furnace from overheating and potential cracks in the heat exchanger

supporting dynamic load ratings up to 28

014-inch orifice size and is specifically engineered for 3/16" tube connections

ensuring stable performance across thousands of ignition cycles

It is fully compatible with both the Sensus 243-8 and 243-12 models

Lennox 36N77 Hot Surface Ignitor Precise Safety Calibration: Maintains aThe Lennox 36N77 Hot Surface Ignitor is a critical OEM replacement part designed for high performance gas fired combustion systems. Also identified by the identical part number 36N7701, this nitride ignitor is engineered to withstand extreme thermal cycling within residential furnaces and boilers. As a direct fit HSI, it ensures precise gas ignition by delivering a robust heat source that interfaces seamlessly with the furnace's integrated control