Today I turned on the oven to pre-heat and after about 20 minutes the temp was about 140. The element at the bottom was not glowing. The cook top was working normally and I tried the broiler and that worked fine. So I turned the oven off and turned it back on. Still no heat. I turned it off and used my wooden toaster tongs to give it a shake, still did not work. For want of a better idea, I went to the basement and flipped the circuit breaker. The oven worked! Can't figure this out. If the breaker was tripped why would the cook top and broiler work. Any thoughts would be greatly appreciated.

Sounds like a bad oven element. Turn off the breaker. Remove the plate holding the element in and then unscrew the element terminals or pull it out depending on your arrangement. Test the element for continuity using an ohmmeter. Set the range scale on R x 1 and place the probes on the element terminals. There should be continuity, with readings ranging from 19 to 115 ohms. Readings will vary according to unit size and the wattage. Look in your manual for any manufacturer's specifications. If there are any signs of element burning, holes or bubbled metal, or if there is no continuity, replace the element. To test for a grounded element, place one probe on the element outer surface and the other on the element terminal. If continuity exists, the element has shorted and should be replaced. Remember to test both terminals. To install a new bake element, reverse the disassembly procedures and reassemble, being sure to follow the wiring diagram and install wires to the correct terminals.