The conversion of net efficiency to gross was achieved by multiplying the netefficiency by the following conversion factor from Table E3 of SAP 2005, roundingdown to the nearest whole number.4. GENERAL INSTALLATION REQUIREMENTS4.1 The installation must be in accordance with these instructions.For the user’s protection, in the United Kingdom it is the law that all gas appliancesare installed by competent persons in accordance with the current edition of the GasSafety (Installation and Use) Regulations. Failure to install the appliance correctlycould lead to prosecution. CORGI requires its members to work to recognisedstandards.In the United Kingdom the installation must also be in accordance with: All the relevant parts of local regulations. All relevant codes of practice. The relevant parts of the current editions of the following British Standards:-BS 715BS EN 1806 which replaces BS 1289 Part 2BS 5440 Part 1BS 5440 Part 2BS 6891BS 1251BS EN 1856 Part 1 which replaces BS 4543 Part 2BS 5871 Part 1BS EN 1858 which replaces BS 1289 Part 1BS 6461 Part 1 In England and Wales, the current edition of the Building Regulations issued bythe Department of the Environment and the Welsh Office. In Scotland, the current edition of the Building Standards (Scotland) Regulationsissued by the Scottish Executive. In Northern Ireland, the current edition of the Building regulations (NorthernIreland) issued by the Department of the Environment for Northern Ireland. In the republic of Ireland the installation must be carried out by a competentperson and installed in accordance with:a) The current edition of IS 813 “Domestic gas installations”.b) All relevant national and local rules in force.c) The current building regulationsWhere no specific instructions are given, reference should be made to the relevantBritish Standard Code of Practice.Page 8© Baxi Heating U.K. Limited 2008.Gas Conversion factor from net to gross efficiencyNatural Gas 0.901LPG 0.921INSTALLER GUIDE