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.

Vecyork, November 2009