INSTALLATION INSTRUCTIONS163.7 Gas ConnectionThe connection to the gas supply must be carried out by professionally qualified personnel inaccordance with relevant standards:When connecting the boiler to the gas supply pipe, only use appropriate washers and gas fittings. Theuse of hemp, Teflon tape and similar materials is not allowed.Before installing the boiler, check the following:■ The pipe work must have a section appropriate for the flow rates requested and the pipe lengths installed, andmust be fitted with all the safety and control devices provided for by current standards.■ The gas supply line must be a minimum of a 22 mm diameter pipe with an uninterrupted supply from meter toboiler and comply with current standards and regulations.■ Check the internal and external seals of the gas supply system.■ A gas shut-off valve must be installed upstream of the appliance■ The gas pipe work must have and bigger or equal section to the one of the boiler.■ Before starting up the boiler, make sure that the type of gas corresponds to that for which the appliance hasbeen set-up (see gas type label inside the boiler).■ The gas supply pressure must be between the values reported on the rating plate (see gas type label inside theboiler).■ Prior to installation, it is good practice to ensure that there are no machining residues on the gas supply pipe.■ Conversion of the appliance from natural gas to LPG or vice versa must be carried out by qualified personnel ;