Plumbing Problems in the UK? Ask a Plumber Now.
Is the fan running?
Any lights at all?
Perhaps it has overheated - or it is not being told to come on?
Is the pump running?
Here is a link to manual;
You should check Fuse 1 in the boiler.
Page 32 onwards has a good fault finding guide if you have a multimeter to check for voltage at certain places.