The challenge is of course Jonty that the scope of most documents published in this subject area are constrained by the intended purpose of the appliances, e.g. heaters used for homes/building or water heaters, etc. and make the unwritten (or stated) assumption that installers are generally qualified and experienced to provide the appropriate safety conditions relating to the appliances, e.g. flues, regulators, safety controls, etc. Generally, they don't really address the scenarios whereby a person purchases an appliance from overseas and then goes about arranging installation themselves or with contractors. I've had some experience in the past with these type of discussion papers - principles and basic guidelines but in many cases they are deemed toothless tigers by the authorities, such as the ESV. I had a real situation 3.5 years ago where the ESV refused to accept some published information from AGA because it was not incorporated within their own manual (dated in the 70's). In Victoria, PLC's are not deemed safe and additional manual safety controls are needed such as proving switches/relays. My advice - perform due diligence or you may find that compliance costs could be as much as the appliance.
