Worcester Junior 28i ignition not firing?

I have woken up to no hot water or heating. We have a Worcester Junior 28i and the red light is flashing (fast so I think 4 times per second??) Usually we turn it off, press the red button then call for heat etc and it fires up but this time it isn't. It sounds like it is trying to but then the red light just flashes again? The dial on the extreme right of the machine has the black needle more or less in the middle but the think right one is at the equivalent of '4 o'clock' (hope that makes sense) Can anyone advise - I am not hopeful of an engineer on a bank holiday (that they will turn up or that I can afford it) Thanks