Siemen Oven won't heat up and fan is on both on fan and oven only ?

I have an 84year old lady who phones me every time she has a problem This time it goes (she is quite senile)
Rang me All my electrics gone (narrowed to my oven ( I Could not go but she said no lights But eventually talked her to resetting timer and all worked except the timer immediately rang the buzzer and she said she felt there was no heat) Eventually I went this morning Timer showed Flashing Symbol I press Stop button All Ok except No heat from element and main fan oven came on in Both, oven only and Fan assisted as well as Cooling Fan
If the element had blown causing reset of power Is it likely to be 2 faults !, Fan 2 Element or could replacing element make oven work normal