Thanks for your reply.
Basically the boiler was working fine until Saturday morning. It had come on that morning with the timer and heated the house and I remember running the hot tap for a long time to clean dishes. Then it cut off.
The red reset lights flashes and the blue status light flashes every 2 / 3 seconds. I have tried the condensor pipe trick having removed it completely. I have reset it a number of times and also turned it off at the wall. On reset it makes some noises, clicking etc, the green gas light temporarily comes on and goes out, the service light too lights up and goes out. It doesn't sound like the fan comes on. However, If I hit the reset button, it goes out as it resets, and then hold it down, the fan or something different seems to kick in and stays on for 10 seconds until the same reset light flashes again. This is different from a normal reset but not sure what that tells you. I have tried running hot tap and turn off heating. No hot water.
If I leave it on with the lights flashing I can hear it if I am in the room above, like it is doing something, the same sort of hum I would normally hear when it first comes on and is warming up the house when it usually works.
Please help. Am stuck with no hot water or heating and my missus is pregnant. BG wont come out til next Tuesday.