I've asked for some quotes to fit a new condensing boiler (my present boiler is 25+yrs old). One of the guys has given me a fair quote but he does not think it necessary to powerflush the system before installing the new boiler. He has said that Powerflushing is "not effective" and is "a waste of money". I thought all systems had to be Powerflushed before a new boiler could be registered? Does this guy have a point? Alarm bells are ringing that I should ignore his quote. Any views?