I would contact Building Control see exactly what they require you to have, you will probably have to get another suitably qualified fitter/installer to check syste ensuring that all safety aspects have been taken into account and that the boiler has been installed in accordance with the Boiler manufacturers literature, if they sign this off this will let Building Control know that the boiler is safe.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!