I have a built in Neff oven which is at least 9 years old. I've had the fan replaced once about 4 years ago. Now the main oven has fan working, but no heat. Do I call repair man out again or just get a new one? Dh said he doesn't care which I do (helpful), but he seems to think an oven should last 30 years because his mum's did. I think replace as there is a slight problem with the grill as well. I'm so indecisive I don't know what to do.