Store › Resistor Assembly for Fireboy System | SPC-SW II Image 1 of 1 Resistor Assembly for Fireboy System | SPC-SW II $27.00 Replacement resistor assembly for the Fireboy system on the SPC-SW II. Includes free economy shipping in the Lower 48. Quantity: Add To Cart Added! Replacement resistor assembly for the Fireboy system on the SPC-SW II. Includes free economy shipping in the Lower 48.