Whaddya' think about this theory? Maybe the 160 degree thermostat was stuck in the closed position, thus causing the temp to operate at 190 degrees (or would it heat to well beyond that with a stuck thermostat?). Then, for some reason, the thermostat unstuck on its own and that's why I'm now hovering around 160 degrees. That's the only thing I can imagine. Thanks again for all of your responses.
