Jan B Litchfield , NH February 17, 2020 Appliance: Jenn-Air Electric Downdraft Surface Unit C301-C Jenn-Air Cooktop C301-C: Burner always on high. How to replace Cooktop Burner Control Knob Kit. Installed a new infinite switch. There may be extra terminals. Just pay attention to which wire goes to which terminal. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes