load of rubbish. you can flush both heating and hot water heat exchangers we do them all the time. your system was either not done right if at all when your boiler was installed. plus it is a regulation that all  systems are powerflushed when new boilers installed. go to this site tells you all you want to no..               WWW.KAMCO.CO.UK
                 hi-spec plumbing
                
 November 2006