In message , Martin Evans
writes

I don't like hedgeing my bets. Ok, since posting the numbers are
interesting since the keep my exisitng system but upgrade my boiler
comes in at £1788 but then dd powerflush ( £330 + VAT)

It might be worth your while looking here

http://www.kamco.co.uk/weblinksENGINEERS.htm

As for prices, sorry, I DIY, always


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geoff