Flexicom cx combination boiler - installation and service manual

12 Commissioning14507MODEMODEDiagram 12.2DO NOT operate the boiler without water.Check that all external controls are calling for heat.Set the Central Heating temperature and the Domestic HotWater temperature to ON by pressing the MODE buttonon the User Interface until it shows the appropriate symbolor and then pressing the - (minus) SELECTOR button.The °C lighting procedure of the boiler is fully automated.The bar digital°Cdisplay, refer to diagram 12.2, will show waterbartemperature in central heating demand.● The appliance will enter a self checking routine then thefan should start and the ignition will commence.The boiler, if necessary, will automatically repeat theignition sequence a further 4 times.● If the burner fails to ignite “F1” will be displayed, initially,this may be due to air in the gas supply line.● Once the system has been purged of air. Set the hot waterto the desired temperature by using the MODE and +(plus) SELECTOR buttons.Open a hot water tap, the diverter valve motor will move tohot water supply and the display will read domestic hot watertemperature.Check that hot water is available at all taps, then close.● Set the Central heating water temperature to the desiredtemperature by using the MODE and + (plus) SELECTORbuttons.The appliance will then continue to operate in central heatinguntil the user controls are satisfied or there is another demandmade for hot water.12.7 Check the Gas Inlet Pressure & GasRateThe supply from the governed meter must be of adequatesize to provide a steady inlet working pressure of 20mbar (8inwg) at the boiler.On completion, test the gas installation fortightness using the pressure drop method and suitable leakdetection fluid, purge as necessary.NOTE: Due to the modulating operation of the boiler andthe need to check the gas inlet pressure and measure thegas rate at maximum rate, it will be necessary to force itto maximum. After a period of 10 minutes, with the boileroperating in C.H. mode, turn on several hot water taps, thiswill operate the boiler at maximum rate.Operational Gas Inlet PressureWith ALL other gas appliances operating, check theoperational supply pressure at the gas service isolation valvetest point, see diagram 12.1.The nominal supply pressure for Natural Gas (G20) is 20mbar.Turn the taps and appliances off, then disconnect the pressuregauge.Additionally the safe nominal maximum heat input of theappliance can be achieved at an inlet pressure down to15mbar.NOTE: The BURNER PRESSURE cannot be measured andis not used to measure the gas rate.40