Lochinvar & A.O. Smith 100109966 Flame Sensor 321894-709 Reduced Mechanical Wear: Prevents refrigerant

Reduced Mechanical Wear: Prevents refrigerant dilution of the oil

because this is a DPDT relay

they often lack the long-term setpoint stability of an OEM Trane CNT3520

and UBX series unit heaters

Lochinvar & A.O. Smith 100109966 Flame Sensor 321894-709 Reduced Mechanical Wear: Prevents refrigerantThe Lochinvar & A. O. Smith 100109966 Flame Sensor is a critical diagnostic component designed for precise flame rectification in high efficiency commercial boilers and water heaters. This OEM replacement flame sensor (formerly part number 9004526005) ensures the burner control module receives a consistent microamp signal, preventing nuisance lockouts and ignition failure. Constructed with high grade alumina ceramic insulation and a durable Kanthal