and resets at 1

this furnace air pressure switch is critical for verifying proper inducer motor draft before allowing the gas valve to energize

provided the spring is correctly calibrated for the gas type

This specific model features a factory-set

The system supports a total of 30 transmitters

Armstrong Fluid Technology 425742-001 Impeller Washer 321702-401 and resets at 1The Armstrong Fluid Technology 425742 001 Impeller Washer is a precision engineered HVAC pump component designed for high performance fluid system maintenance. Engineered to meet exact Armstrong pump repair parts specifications, this stainless steel washer ensures optimal axial positioning and stability for the impeller assembly. By maintaining tight tolerances within the pump casing, it prevents excessive vibration and premature wear on the rotating