For no reason, the display panel started flashing f1 and beeping. I would press the cancel button on the lower over (because nothing would happen when canceling the upper oven) and the flashing and beeping would stop for about 30 seconds. I did this 3 or 4 times before turning off the breaker for 1 hour. After turning the breaker back on, we have not had a problem since (only been about 15 minutes though). What does the f1 mean, and why was is flashing and beeping?