Ideal Boilers Mexico Super RS485 Installation And Servicing

31Mexico Super RS485 - RS4125 - Installation & ServicingFAULT FINDINGFAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDINGDetailed instructions on the cleaning and adjustment orreplacement of faulty components are contained in the'Servicing' section of this publication.Before attempting any electrical fault finding ALWAYS carryout preliminary electrical system checks, i.e. earth continuity,polarity and resistance to earth using a suitable meter.Check mains neon on PCB.Is it illuminated?YESNOIs there a live supply toboth terminals of overheat'stat?(If non- overheat 'statgo to next step).YESNOCheck the control 'stat isset to max and mainsswitch is on.Is there a regular sparkfrom tube SG1 on thePCB?Check mains supply and fuses. Check controls arecalling for heat. Check boiler wiring connections are OK.NOCan the overheat thermostatbe reset with the system cold?Replace fuse but before restoring power check for short circuitbetween L/N and L/Earth on all components plugged into thePCB.Check gap at ignition electrode. Check electrode and leads are not damaged.Check the lead is not shorting to earth. Rectify as necessary.Replace the overheat 'stat.Has the fuse on the PCB blown?Reset the overheat 'stat. Set control'stat to maximum. Allow the boiler toreach temperature - if the overheat 'stattrips again, measure flow temperature.If above 90∞C replace control 'stat.If below 90∞C replace overheat 'stat.YESIs there a spark at theignition electrode?Does the pilot burner light?NOIs there a gas supply to the boiler &has the gas supply been purged ofair?Connect or rectify andpurge the system of air.NOYESReplace the PCB.NO YESNOYESNOYESNOYESNOEnsure pilot and main gas valve leads are notcrossed over. Is there a supply voltage at the pilotgas valve?Is the pilot injectorblocked or the pilotsupply pipe damaged? Rectify or replace as necessaryCheck connections at the gasvalve and rectify as necessary.If no connection fault foundreplace PCB.Replace gas valveYESDoes the spark stopafter the pilot is lit?YESDoes the main burnercross-light from the pilot?NOCheck polarity of mains supply. Checkcontinuity of ignition lead.Does spark now stop when pilot is lit?Is there a supply voltage at the main gas valve?Check connectionsto PCB.If no fault changePCB.Is the main injector blocked? Replace main gas solenoid valve.Does the main burner light?YESNOYESClear blockage and refit.Does main burner light?YESNOReplacegasvalveYESNOYESNOBoileroperatingsatisfactorilyCheck for correct gassupply pressure.Rectify as necessary.NOYESYESNONOFAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING