The GN series utilizes updated materials for better thermal resistance and longevity compared to the discontinued GF series while maintaining identical mounting dimensions

Always verify your serial number and fuel type before installation

The K16RA-36 thermocouple is engineered for high-ambient temperatures

making it a reliable OEM replacement part for critical combustion environments

Lochinvar & A.O. Smith 100112678 Flame Sensor 323613-751 The GN series utilizes updatedThe Lochinvar & A. O. Smith 100112678 Flame Sensor is a critical OEM safety component engineered for precise flame rectification in high efficiency boilers and water heaters. Designed for Lochinvar Knight and A. O. Smith B4940, B5930, B5940, and B7930 series units, this sensor monitors the burner's ionized path to ensure the gas valve remains energized only when a stable flame is present. Constructed with a high grade Kanthal or equivalent alloy rod