A IS THE PUMP RUNNING? NO YES POWER TO THE PUMP? YES 1 - Check that the pump is not stuck 2 - Release/replace pump NO 1 - Check DHW flowswitch 2 - Check pump cable 3 - Check/replace P.C.B. IS THE FAN RUNNING? YES NO POWER TO FAN ? YES NO 1 - Check/replace connection cable 2 - Check/replace P.C.B. 1 - Replace fan IS SPARK GENERATION FOR IGNITION NORMAL? YES NO 1 - Check/replace ignition electrode 2 - Check ignition cable 3 - Check spark generator 4 - Check ignition electrode cable 5 - Check/replace P.C.B. IS THE BURNER ALIGHT? YES NO 1 - Check power supply of gas valve 2 - Check/replace P.C.B. 3 - Check efficiency of gas valve 4 - Replace gas valve HAS THE BOILER SAFETY SHUTDOWN BEEN ACTIVATED? NO YES 1 - Check if flame strikes detection electrode 2 - Check soft-light gas pressure 3 - Check/replace detection electrode 4 - Check/replace P.C.B. B FC P013 62
B IS THERE STILL A PROBLEM? NO NORMAL OPERATION YES FAULTS 1 Drawing D.H.W: When you turn on a tap burner switches off 2 Drawing D.H.W: radiators heat up in summer mode 3 Drawing D.H.W: insufficient hot water temperature POSSIBILE CAUSES - check temperature probes - faulty D.H.W. flow switch - faulty 3-way valve - check temperature probes - check gas pressures - check water flow rate 4 5 Drawing D.H.W: noisy operation Decrease/increase heating circuit pressure - primary heat exchanger faulty or lime-scale deposits - low heating system water pressure - check gas pressures - check temperature probes - check for leaks on the heating circuit - faulty filling-loop - expansion vessel faulty 6 7 8 9 Repeated shutdowns Repeated intervention of safety thermostat When cold water tap turned off, the boiler ignites Insufficient radiator temperature - faulty detection electrodes - check gas settings - check flame detection electric circuit - check temperature probes - overheat thermostat not calibrated correctly - air in primary water circuit - drop in pressure in the water mains, with consequent water hammer - check C.H. temperature probe - check by-pass and pump speed - check gas pressures FC P014 63
A IS THE PUMP RUNNING? NO YES POWER TO THE PUMP? YES 1 - Check that the pump is not stuck 2 - Release/replace pump NO 1 - Check DHW flowswitch 2 - Check pump cable 3 - Check/replace P.C.B. IS THE FAN RUNNING? YES NO POWER TO FAN ? YES NO 1 - Check/replace connection cable 2 - Check/replace P.C.B. 1 - Replace fan IS SPARK GENERATION FOR IGNITION NORMAL? YES NO 1 - Check/replace ignition electrode 2 - Check ignition cable 3 - Check spark generator 4 - Check ignition electrode cable 5 - Check/replace P.C.B. IS THE BURNER ALIGHT? YES NO 1 - Check power supply of gas valve 2 - Check/replace P.C.B. 3 - Check efficiency of gas valve 4 - Replace gas valve HAS THE BOILER SAFETY SHUTDOWN BEEN ACTIVATED? NO YES 1 - Check if flame strikes detection electrode 2 - Check soft-light gas pressure 3 - Check/replace detection electrode 4 - Check/replace P.C.B. B FC P013 62
B IS THERE STILL A PROBLEM? NO NORMAL OPERATION YES FAULTS 1 Drawing D.H.W: When you turn on a tap burner switches off 2 Drawing D.H.W: radiators heat up in summer mode 3 Drawing D.H.W: insufficient hot water temperature POSSIBILE CAUSES - check temperature probes - faulty D.H.W. flow switch - faulty 3-way valve - check temperature probes - check gas pressures - check water flow rate 4 5 Drawing D.H.W: noisy operation Decrease/increase heating circuit pressure - primary heat exchanger faulty or lime-scale deposits - low heating system water pressure - check gas pressures - check temperature probes - check for leaks on the heating circuit - faulty filling-loop - expansion vessel faulty 6 7 8 9 Repeated shutdowns Repeated intervention of safety thermostat When cold water tap turned off, the boiler ignites Insufficient radiator temperature - faulty detection electrodes - check gas settings - check flame detection electric circuit - check temperature probes - overheat thermostat not calibrated correctly - air in primary water circuit - drop in pressure in the water mains, with consequent water hammer - check C.H. temperature probe - check by-pass and pump speed - check gas pressures FC P014 63
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