Worcester boiler 28 cdi - Re igniting when lit?

I have had a number of problems with a Worcester 28 CDI recently. The board had to be replaced as a circuit had gone. This didnt solve the issue which was then diagnosed as a faulty fan (which was very stiff to turn). It looks like one took the other out.

Anyway, all fixed, less than 24 hrs the boiler is playing up again. If i tuen the CH on or demand hot water the boiler fires up and runs and then after 2 minutes or so, you can here it trying to re-ignite even though its already lit. Looking through the window you can see the flame go brighter with each click of the igniter. It does theis a few times then goes back to normal then it does it again, then it stops / shutsdown and the rad light flashes. I then have to reset and it does the same again.

Earlier in the year I also had the board replaced, diaphram and diverter so surely there cant be that much more to go wrong, however its strange it worked for 24 hrs before breaking again.