Oven not working?

Hi, recently I had a power cut whilst Neff oven was on, I restored power throughout the house but the oven didn't return. I have pressed the left sided button until the red upside down triangle moves along to hover over the arrow pointing to the right which then allows me to adjust the oven knobs to heat it. The oven is not heating. The grill, fan etc is working......please can you help?