How to Install a Corner Cooktop

Mark the space on the countertop for installation of the cooktop, using a tape measure to draw the outlines as specified by the manufacturer for a rough opening. Measure in a corner to make sure all walls are the safe distance specified by the manufacturer, generally at least 24 inches from any heat. Turn off all gas and electric service to the countertop with cutoffs or circuit breakers.

Cut the rough opening with a reciprocal saw in a plywood or other wood countertop. Cut Formica or similar material with a saw recommended by the manufacturer. Hire a professional to cut a rough opening in granite or other stone tops.

Set the cooktop unit in the opening and secure it with bolts, tabs or clips; this will vary with the manufacturer. Read the unit instruction manual if the fasteners are not obvious. Use a level to ensure the unit is level on the countertop -- adjust it if necessary with shims or according to instructions with the unit; some cooktops have adjustable mounting screws that you can tighten or loosen to level the top. Tighten fasteners with wrenches or screwdrivers, depending on the type.

Attach gas lines to cooktops with the screw-on connectors on the unit; seal the connection by wrapping the threads first with Teflon tape specified for gas use. Plug the electrical connection for a gas unit into a plug under the cabinet. Wire an electric cooktop by connecting its three wires -- black, white and bare copper -- with wire nuts to the appropriate wires in a junction box under the cabinet.

Restore gas and electricity and test all connections by turning on the cooktop. Turn it off immediately if there is any smell of gas or sparks and call a professional serviceman if you cannot instantly identify and correct the problem. Put a cover on an electrical junction box. Add any burner covers or other accessories.