While it fits standard duct sizing used in these systems

as repeated tripping indicates a serious underlying airflow or combustion issue

What is the primary indicator that the pilot assembly needs replacement

Ensure power is disconnected and the old capacitor is discharged before installation

it must be installed with the flow arrow pointing toward the expansion device for proper filtration

York S1-028-12385-700 Sheave While it fits standard ductThe York S1 028 12385 700 Sheave is a professional grade 1 groove variable pitch pulley engineered for precision air balancing in commercial and residential air handlers. Featuring a standard 7 8 inch bore, this adjustable component allows technicians to fine tune blower speeds and system CFM by modifying the pitch diameter. As an OEM S1 028 12385 700 replacement, it ensures exact mechanical compatibility with Johnson Controls and York blower