Problems with Worcester Bosch Greenstar Ri?

Hi,
We have the above boiler, it started making clicking noises a few weeks ago (its 5 years old) when we turned the heating off at night, we were waiting for our gas man to come so started turning the boiler off at night to stop the clicking. A week later the boiler went out altogether, came back on with re-set, but the green light is never on and the pump still runs when we turn heating off. Gas man says there is an intermittant fault and is calling me back later to discuss options, just wondered if anyone else has had similar problems? Thanks