whereas the AF-2 is specifically calibrated for low velocity air flow detection

this assembly is the designated replacement for several older part numbers including 20460603 and 20517902

000 Ohm sensitivity rating

matching all electrical and physical specifications

Key Benefits: System Safety: Prevents furnace ignition if improper venting or inducer failure is detected

Patterson-Kelley 26-4000-0128 Ignitor 326058-755 whereas the AF-2 is specificallyThe Patterson Kelley 26 4000 0128 Ignitor is a critical high precision component engineered specifically for commercial boiler ignition systems. Designed for use across the Patterson Kelley Mach and P K Compact series, this direct spark ignitor ensures consistent electrode gapping and reliable arc generation in high demand hydronic applications. Veterans in the field recognize this assembly for its robust ceramic insulation and high temperature alloy