Copeland Comfort Control (White Rodgers) F91-3889 120V Secondary Replacement Coil

The Emerson Climate-White Rodgers F91-3889 Secondary Coil is an electromagnetic coil used in gas valve and relay assemblies to provide switching action. It operates by energizing a copper winding with 120 VAC, generating a magnetic field that actuates valve or relay movement for opening and closing electrical or gas flow paths. In HVAC systems such as furnaces and heating units using 25M series valves, it is fitted inside the valve assembly housing and connected to the control circuit terminals. It restores coil-driven switching response, reduces interruption in valve operation, and maintains consistent system cycling in heating equipment.