Indesit W123 won't start?

I have an Indesit W123 which is about 6 years old. Yesterday I came home to find the dial rotating so I checked the pump outlet and found nothing. Now when I try to turn it on the door locks and the light goes on constant but nothing happens.
Anyone got any ideas before I spend any money! It has happened before and just tends to clear itself but not this time.
Thank you in advance.