Armstrong Furnace R604221-01 Switch always verify the specific screw

always verify the specific screw size of your controller before applying torque

5 MFD) in a single compact round capacitor footprint

While designed for differential velocity pressure

Always cross-reference the burner orifice stamp with the conversion kit technical data provided in the installation manual to ensure correct gas flow

Armstrong Furnace R604221-01 Switch always verify the specific screwThe Armstrong Furnace R604221 01 Door Switch is a critical safety interlock component designed for modern HVAC systems. This furnace door safety switch functions as a primary disconnect, ensuring the blower motor and burner assembly cannot operate when the service panel is removed. Engineered to withstand high cycle operations, this interlock switch replacement serves as a direct OEM component for Armstrong, AirEase, and Ducane units. Proper