Thanks for the ideas guys.
This morning the boiler is on again so I am leaning towards the clock being the problem. Short term fix has been to extend the on period until tonight. I will track down a timer. If this doesn't work I'll bypass the clock.
First I know ravenheat boilers have a poor reputation but thats what I've got and am stuck with.
Sorry for the long post.
Currently I can get hot water no problem but the heating does not come on. I have linked out the thermostat and that made no difference.
I then checked that the pump...