Thanks for that Eric.
Having spoken to several other people I have finally sorted it out & for others out there who may be in the same boat, I have added the solution below.
The boiler was fine, it was the thermostat that was the problem.
1. We removed the batteries from the T Stat for approx. 1/2 hour.
2. We added new batteries to the T Stat & put them into the unit.
3. We then pressed the Reset button on the boiler panel (denoted by a triangle with an exclaimation mark inside it)
4. The boiler then seemed to run through a set if tests.
5. Finally the radiators began to heat - SUCCESS!
Thanks again for you help & hope this may assist others.
Damsel in Thermals
January 2014