Combi CSl 85T Boiler leaking?

I have had my regular plumber out to my Revenheat CSl 85T Boiler, which is only 6 years old, as it is leaking at the bottom he has had a thorough look and came to the conclusion that it could be the Seconday Heater Exchange thats gone however to get to one of the valves is almost impossible as the valve is at the back of the casing on the right hand side, he had a crow tool but could not get near it does anyone know how to do this please. This happened on Friday 23 September so I am left with no hot water or heating can't contact anyone till Monday.