warmflow boiler?

I ran out of oil I have a warmflow u series with a rielller 3.2 burner, I put 50 litres in while waiting on a delivery and pressed the red button on the burner and it fired briefly so I tried it again a couple of times, now the boiler won't even start, all the lights are on opened the bleed Allen screw on the burner but the boiler seems locked, is there any reset or anything i can do to get the pump turning? ta