Always check the part number stamped on the side of the original pressure switch

concentrated blue flame for maximum combustion efficiency

installers should verify if existing plugs are reusable or if new 3/4-inch NPT plugs are required for the secondary ports

The Honeywell C554A1463 is a high-sensitivity cadmium sulfide flame detector engineered for precise photoconductive flame sensing in sequencing oil burner systems

Common indicators include the furnace failing to ignite after the inducer motor starts

System Sensor D4120 Detector 30067439-890 Always check the part numberThe System Sensor D4120 is an industrial grade 4 wire photoelectric duct smoke detector designed for high performance smoke detection in HVAC air handling systems. This InnovairFlex duct smoke detector operates across a wide air velocity range of 100 to 4,000 feet per minute, making it suitable for both low flow and high volume applications. It features a versatile pivoting housing that accommodates square or rectangular footprints and mounts easily