Robert S Horseshoe Bay , TX January 01, 2017 Appliance: Thermador CMT-21 SERVICE CODE J & UP Thermador Oven Cmt-21: Oven element burnt out. How to replace Element, Bake. Replaced oven element in upper oven of a 35 year old Thermador double oven Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes