Mary S Topeka , KS June 18, 2016 Appliance: Whirlpool Electric Range RS670PXK1 Whirlpool Range Rs670pxk1: Range cooktop knobs were broken. How to replace Range Top Burner Control Knob. Ordered new ones online fro appliance Parts Pros. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes