How to Find your Serial / Model Number - Cooktops Last updated Save as PDF Cooktop Located on the base pan of the appliance which sits below the bench. If the appliance is installed where the serial number cannot be located, it will usually be at the back of the customer’s user manual. Cooksurface Serial label located on the underside of the cooktop near the gas entry point on the left. There is also a label on the front left of the chassis which might be visible in some installations.