Gas engineers have to be on the register to do safe and authorized fuel installations and service fuel appliances. http://[email protected]/info.php?a%5B%5D=%3Ca+href%3Dhttps%3A%2F%2Fwww.webwiki.ch%2F%3Egas+engineer+tools%3C%copyright%3E%3Cmeta+http-equiv%3Drefresh+content%3D0%3Burl%3Dhttps%3A%2F%2Fzenwriting.net%2Foceanviola39%2Fthe-relevance-of-gas-security-certifications-for-rental-properties+%2F%3E