You have to define "work on a gas installation" - switching on a boiler is not "work" done on it; bleeding a rad is surely not counted as "work on a gas installation"; turning on a radiator valve - is that "work on a gas installation"?
Morally I agree -one should do a safety check, or advise the user to get one before using the appliance (as I did), but legally I can't see there being a case for turning on an appliance in the same manner that the end user would do (unless they had been advised not to).
Morally I agree -one should do a safety check, or advise the user to get one before using the appliance (as I did), but legally I can't see there being a case for turning on an appliance in the same manner that the end user would do (unless they had been advised not to).