Doesn't this come under the loop hole that you can fit what you want in your own property as long as your not doing it for gain ! and the only way it will ever be stopped is if the general public are stopped from buying gas appliances, but we all know this will never happen, it's been looked into , but comes under restrictive practice , Have been asked loads of times in the past about doing the same thing, so they can get the warranty on the boiler, not sure how the house insurer would look on customer installing own gas appliance, would they invalidate any policy immediately or just wait until something happened ????? and how meny would tell insurance company in the first place, This just makes a mockery of everything we have to go through do our job.