McDonnell & Miller 63-M-HD Head Mechanism 30067439-890 Key Benefits Precise Flame Detection:

Key Benefits Precise Flame Detection: High-sensitivity metal electrode ensures accurate ionization signaling to the burner control module

The 5/8" bore must match your motor shaft diameter exactly

and fits a standard 5/16-inch inducer motor shaft

it ensures seamless integration with existing York

Direct OEM Fit: Drop-in replacement for the HC35VE209

McDonnell & Miller 63-M-HD Head Mechanism 30067439-890 Key Benefits Precise Flame Detection:The McDonnell & Miller 63 M HD Head Mechanism (Part Number 143200) is a heavy duty replacement head mechanism designed for the Series 63 Low Water Cut Off. Engineered for both hot water and steam boilers, this manual reset mechanical control ensures critical safety by interrupting the electrical circuit to the burner in 15 psi steam or 50 psi water applications. It features a robust float operated design and includes the No. 2 M switch, providing