or if your multimeter shows an open circuit or significant resistance between the furnace transformer and the board pins

the synchronous motor drive may require replacement

this double pole double throw component provides isolated control for multiple circuits

protecting the heat exchanger when water levels drop below the critical threshold

Key Benefits Precise Thermal Monitoring: Delivers accurate resistance readings to the control board to prevent system freezing

Greenheck 318864 Motor 318820-201 or if your multimeter showsThe Greenheck 318864 Motor is a high performance 115V 3 4 HP replacement motor engineered specifically for heavy duty ventilation and air handling applications. Operating at 1300 RPM, this motor provides the torque and velocity necessary to maintain proper static pressure in Greenheck fan systems and industrial HVAC equipment. This unit features a counterclockwise lead end (CCWLE) rotation, a critical technical specification for ensuring correct