Peggie D Prescott , AZ September 24, 2015 Appliance: Magic Chef Gas Wall Oven 9112WPA Magic Chef Oven 9112Wpa: Knob busted!. How to replace Knob, Thermostat (Chrome). I simply ordered a new knob from this website and it was quick & easy! The photo of the part was good and I was confidant that if the busted knob was the problem, then it would work!!!And most important it worked!!! 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes