BRAND-NEW-IN-BOX CARRIER MAIN BOARD. Brand new Carrier HK42FZ034 Furnace Control Board for central furnaces and air conditioners. This corded electric control board is compatible with Carrier, Payne, and Bryant brands. It is a reliable and efficient replacement part for your HVAC system’s control and circuit board needs. Ensure your furnace or air conditioner is working at its best with this high-quality control board. Don’t let a malfunctioning control board affect your system’s performance and energy efficiency. Choose the Carrier HK42FZ034 Furnace Control Board for a durable and long-lasting solution.