As temperatures dissipate below the 105°F cutout

For applications requiring weather resistance

Ensure the unused primary lead is properly capped to avoid electrical shorts

Key Benefits Precise Thermal Management: Features a 165°F activation point with a 35°F reset differential for reliable furnace blower fan control

which can accidentally enlarge the opening and cause improper combustion

Williams 7B111 Fan Blade 30067439-890 As temperatures dissipate below theThe Williams 7B111 Fan Blade is a critical replacement component designed specifically for Forsaire Counterflow Top Vent furnaces. This 8 blade aluminum assembly is engineered for 65,000 BTU models, including the Williams 6508 series, where maintaining precise static pressure and consistent CFM is vital for heat exchanger integrity. Featuring an 11 1 4" diameter and a 1 2" bore, this CW (clockwise) rotation blade ensures the blower assembly moves air