As a critical motor starting relay

The Parker 70712 is a professional-grade 3/4" NPT solenoid valve designed for high-performance fluid control in commercial and industrial HVACR systems

While designed for a direct swap

and Tempstar brands

Carrier HK42FZ039 Control Board R-134A As a critical motor startingThe Carrier HK42FZ039 Control Board is a critical OEM replacement circuit board engineered for high performance management of residential HVAC furnace and air handler systems. This gas furnace control board serves as the central processing unit, regulating ignition sequences, blower motor speeds, and safety limit circuits. Built to genuine Carrier HVAC parts standards, the HK42FZ039 ensures precise timing for draft inducer motors and gas valve