If you can hear the fan but the oven isn't heating up then yes, it probably just means the heating element is broken.
When mine did that, I checked in the manual which one I needed for my oven & ordered it online (not expensive), but then got an oven technician out to check that was the only thing wrong and to instal the element for me - that way I only paid one call-out fee, rather than getting him round to tell me that the element was broken and he'd have to order one, and come back in a few days to fix it.
I've had to replace the heater element on a previous Neff oven about three times. A lot cheaper than replacing the oven although I know a friendly electrician! I got the part from a local shop which just deals with spare parts rather than from Neff.
My (built-in) electric fan oven isn't working, grill seems to be absolutely fine, but when I put the fan assisted oven thingy on - nothing . Anyone know if this is a fixable problem (v skint at the moment, so really, really hoping this might be the case) or not?? It's about 6 years old.........