You Cannot do this yourself as you will be breaking the law as both gas pipes and flue parts have to be dismantled. you MUST use a Registered Gas Engineer to carry out this work, best to have the Boiler Serviced at the same time, it is important that back Boiler units are serviced EVERY YEAR, as when things go wrong with them it can be very serious
www.gassaferegister.co.uk will hepl you to find a RGI near you
www.elanar.co.uk, July 2009
