Can someone clarify the law as regards installing a gas combi boiler without payment. The law seems to permit a competentperson to make such an installation in their own home or elsewhere provided payment is not involved. I should make clear that, in years gone by, I have already installed several boilers and then had them subsequently checked by Corgi engineers (without ANY problems or rectifications needed). Under the latest regulations regarding notification of new installations, could I install a combi in my son's house, and get it inspected bya Corgi engineer? What would be a reasonable charge for such an inspection & sign-off, bearing in mind all the work has been done?