Cheers for the replies, looks like i'm going to have a bit time on my hands over the next week or two so i'll give flushing it a shot... whats the best way of doing this?
Regarding the installer - he was a council fitter who is Corgi Registered just not for private jobs, i'm confident he did...
Desperate for some help here, I stupidly went cheap on the boiler when I rennovated my house and bought a Heatline Vizo 24, I have had a few issues with it - mainly the central heating.
Its been cold recently so I decided to turn on the heating for the first time since earlier in the year...