Installation And Servicing Instructions - Heatingspares247.com

NWD209/1/2000 Chapter 5 : Fault Finding The Keston Celsius 25 & 25PIGNITION FAILUREIs there 230VAC betw een PL & Nand SL & N at mains connection block.?NThe polarity of the permanent or sw itchedlive supply is reversed. RectifyY YIs there at least 18 mbar dynamicpressure at the gas valves inlet(ie w hen the boiler fires orattempts to fire)?NIncorrect gas supply to boiler.Rectif yIs the condensate trap blocked?NClear blockage and allowcontacts to dry.NYIs modulation LED2 illuminated?NReset lockout. After up to120 seconds does the fan run?NIs there 24VDC at fanconnection (B) on control PCB?YIs there 24VDC at the fan (C)?YReplace fan?NNYReplace control PCB?Wiring from control PCBto fan unit faulty.After up to 10 seconds moredoes the yellow "boiler on"lamp flash rapidly?NNo air flow . Is the flue/airsystem correctly fittedand free of obstruction?YReplace ignition PCB.NYRectify flue/air systemIs there a sparkpresent?NIs there 230VAC atcontrol PCB (D)?Is the spark probeY or HT ignition lead Ndamaged?Is the spark gas3 ... 4 mm?YReplace ignition PCB.NYYReplace control PCB.Replace spark probe.Set spark gap to 3mmIs there gas present?NIs there 230VAC presentat ignition PCB position (E)?YIs there 230VAC at gasvalve connection (F)?YAre gas valvesolenoids faulty?NReplace gas valveYNNYReplace ignition PCB.Replace gas valve lead.Replace solenoid(s)Is the burner pressureand combustion set correctly?YIs there 230VAC at position(G) on ignition PCB?YIs there 230VAC at position(H) on control PCB?YReplace control PCBNNNReplace ignition PCBWiring betw een ignition PCBand control PCB faulty.SERVICE BOILERInstallation & Servicing Instructions Page : 36