Open the cabinet door beneath the cooktop and check the power cord to ensure the cooktop is plugged into a grounded electric outlet.
Push in the burner's control knob and turn it to the "LITE" position. The ignitor clicks and produces a small spark when it is functioning normally.
Check the manual shutoff valve underneath the cooktop's counter. A shutoff valve turned clockwise is off, which restricts gas from reaching the cooktop. Turn the manual shutoff valve counterclockwise to restore gas to the cooktop's ignitor.
Lift off the burner grates and burner heads once they have cooled off after use. Wipe down the ignitor electrode found underneath the burner head to clean it.
Set the burner head and burner grate back onto the cooktop. Push and turn the burner's knob to test the ignitor.