John G Bakersfield , CA February 13, 2016 Appliance: Jenn-Air Gas Cooktop JGC8430BDS Jenn-Air Cooktop Jgc8430bds: Broken knob on gas cook top. How to replace Burner Knob. The knobs simply pull off and on with a very snug fit. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes