Ideal Boilers Classic FF 250 P Installation And Servicing Manual

34 Classic FF - Propane InstallationFAULT FINDINGReset the overheat 'stat. Set control'stat to maximum. Allow the boiler toreach temperature - if the overheat'stat trips again, measure flowtemperature.If above 90°C replace control 'stat.If below 90°C replace overheat 'stat.STARTCheck that the mains on neon'I3' is illuminated.YESNOYESYESNOIs there a live supply to bothterminals of overheat 'stat?Is the ignition electrode sparking?YESYESYESChange fanYESNO Rectify bad connectionCheck mains supply and fuses.Check programmer and systemthermostats are all ON. Check thatboiler plug and socket are OK andfully connected.YESCheck connections to pressureswitch. If no faults found, changepressure switch.Replace the sensorCheck connections and leads topressure switch/boiler thermostatand check that fan is operating.Check all connections to PCB.If no fault found change PCB.YESCheck pressure switch sensingpipes for blockages, badconnections and reversedconnection.Is pressure difference at switchgreater than 0.9 mbar?Change fanNOIs the boiler casingcorrectly fitted?Does main burnercross-light from pilot?Does the pilot light ?NOYESYESDoes thespark stopafter pilot islit?NOIs there a gas supplyto the boiler?Is the pilot injectorblocked?YESReplacegas valveNOIs there a supply on terminalsof main gas valve?YESNOYESNO NOIs there a supply on the fanconnector at PCB ('Molex 'marked 'FAN'?).YESYESNOYESCheck the polarity ofthe mains supply.Check the continuity ofthe ignition lead fromconnector to electrode.Does the spark nowcease when gas is lit ?Ensure pilot andmain gas valveleads are notcrossed over.Is there a supplyvoltage at pilotgas valve?NOIs there a regularspark from tube 'SG1'on the PCB?Can the overheat 'statbe reset when thesystem is cold ?NO YESNOReplace fuse BUT, beforeattempting to start boiler, checkfor short between live andneutral, also between live andearth, on all items plugged intoPCBCheck all connections to PCB.If no error found, replace PCB.Remove the sensor(NTC) from the PCB.Is the fan turning ?YES NONOYESHas the fuse blown on PCB ?NONOIs there a live supply on theviolet lead to pressure switch?Is there asupply atthe fan ?Replace the overheat thermostatCheck that the boiler thermostatis set at maximum and the mainson/off switch is ON.Is the fan turning ?Is there a livesupply on the redlead to pressureswitch?Is the main burnerinjector clear?Replace main gassolenoid valveNOChangepressure switchYESCheck gap at ignition electrode.Check electrode and lead areundamaged, and not close toearthed metalwork.Check all connections to PCB.If no fault found, replace PCBFAULT FINDING