Could be your Thermal Fuse. If it's open circuit, and they fail due to old age, it will cause a 'no operation' and perhaps shut off power to your electric element too through a relay.
It's easily spotted as it's inside a piece of black tubing with a kink in it that's in a wire leading to the control module. Right inside the WH cabinet just under the outside panel. The fuse is 1/8" in diameter and 1/2" long. You can remove it and short out the wire ends to test by making a short jumper. Or test the fuse with an ohmmeter.