Wells Controller Repairs Repair Cost $389 Wells M4200 Oven Controller 2-YEAR WARRANTY. Part Numbers: 64964, 44964. Used in Model M4200. Includes Genuine Wells Graphic Overlay. Repair Cost $389 Wells M4200-3S Oven Controller 2-YEAR WARRANTY. Part Numbers: 2J-306966, TWC-OC752-010G, TWL-OC752-010. Used in Model: M4200-3S. Includes New Graphic Overlay.