- 53 -ENGLISHOPERATION AND MAINTENANCEPRELIMINARY CHECKSOnce having completed the water, electrical and fuel connections to the boiler, before starting, check that:- The expansion vessel and the safety valve (if required) are connected correctly and cannot be shut-off- The bulbs of the thermostats and the thermometer are secured inside the corresponding sheaths.- The turbulators are positioned in all the flues.- The system is filled with water and completely vented of air.- The pump or the pumps are working properly.- The water, electrical, safety device and fuel connections have been performed in compliance with the national and local legisla-tion in force.- The burner is installed according to the instructions contained in the manual provided by the manufacturer.- The mains voltage and frequency are compatible with the rating of the burner and the boiler’s electrical equipment.- The system is able to absorb the quantity of heat that will be produced.- The recirculating pump is installed, as described on page 48.STARTING FOR THE FIRST TIMEAfter the positive outcome of the checks described in the previous paragraph, the burner can be ignited for the first time; this ope-ration must be performed by a technician who has been authorised by the Manufacturer of the burner. The technician has fullresponsibility as regards the field of calibration, within the declared and approved output range of the boiler. After having openedthe fuel on-off cocks and checked that there are no leaks in the supply line, place all the switches on the ON position.The burner will thus be ready for first ignition and for the adjustments to be made by the authorised technician.On first ignition, check that the door, the burner flange and the connections to the chimney are tight and that there is a slight nega-tive pressure at the base of the flue stack. The fuel rate must correspond to the boiler's rated data and under no circumstances mustexceed the maximum output value declared. The temperature of the flue gas must never fall below 160°C.SHUTTING DOWN THE BOILER- Set the temperature controller to the minimum.- Disconnect power from the burner and close the fuel supply.- Let the pumps operate until they are stopped by the temperature controller.- Disconnect power from the electrical panel.