Ferroli boiler troubleshooting



The use of Ferroli boilers for hot water supply systems is an ideal solution for those cases, when a high flow rate of hot water is required. There are other cases, when Ferroli boilers are an ideal solution. Ferroli boiler troubleshooting system provided in the table below is an ideal solution for diagnostics of any Ferroli appliance.

Ferroli DOMIcompact F  boiler troubleshooting

FaultDisplay codePossible causeCure
No burner ignitionF1• Nogas• Check the regular gas flow to the boiler and the air has been purged from the pipes.
• Detection or ignition electrode fault• Check the wiring of the electrode and that it is correctly positioned and free of any deposits
• Defective gas valve• Check and change the gas valve
• Ignition power too low• Adjust the ignition power
• Condensate discharge full or dirty• Check and clean condensate discharge
Flame present with burner off signalF2• Electrodefault• Check the ionizing electrode wiring
• PCB fault• Check the card
Safety thermostat tripsF3• Heating sensor damaged
• No water circulation in the system
• Air in the system
• Check the correct positioning and operation of the heating sensor
• Check the circulator
• Vent the system
• Check the system bypass is sufficient
Air pressure switch (fails to dose the contacts within 60 sec. of turning on the fan)F5• Air pressure switch contact open• Check the wiring to the fan
• Incorrect wiring to the air pressure switch• Check the pressure switch
• Incorrect restrictor ring fitted• Change the restrictor ring
• Flue not correctly sized or obstructed• Check the fan venturi
Delivery sensor faultF7• Sensor damaged
• Wiring shorted
• Wiring broken
• Check the wiring or change the sensor
Tap water sensor faultF9• Sensor damaged
• Wiring shorted
• Wiring broken
• Check the wiring or change the sensor
Low system pressureF37• System empty
• Low Water pressure switch not connected or damaged
• Fill the system to 1 -1.5 bar
• Check the low water pressure switch

Ferroli Optimax 25 C boiler troubleshooting

FaultPossible causeCure
F1No burner ignition•No gas•Check the regular gas flow to the boiler and the air has been purged from the pipes.
•Detection or ignition electrode fault•Check that the electrodes are correctly positioned and free of any deposits
•Defective gas valve•Check and change the gas valve
•Incorrect inlet gas pressure•Check inlet gas pressure
•Siphon obstructed•Check and if necessary change the siphon
F2flame detected with the burner off•Ionisation electrode defected•Check the ionizing electrode wiring
•Main board defected•Check the CVBC
F3100°C Safety thermostat trips•Flow sensor not active or correctly located•Check the correct positioning and operation of the flow sensor
•No system circulation•Check the pump and radiator valves present in the system
F5Fan problem•Tachometer signal interrupted, fan connection•Check the wiring and fan
•Fan damaged, debris in fan•Check the fan, clean debris
F8No flame after the ignition phase•CVBC fault•Check and if necessary change the CVBC
•Ionisation probe fault•Change/clean ionisation probe
•Mains interference•Check the earthing
F9No communication between the CVBC and the gas valve•Incorrect wiring
•Damaged valve
•Check the wiring
•Check the CVBC
•Change the valve
F10 -F22Microprocessor trouble• Microprocessor operating trouble• Cut off and restore the electricity supply. If the trouble remains, check and/or change the main PCB
F25Software fault• Software operating fault• Cut off and restore the electricity supply. If the trouble remains, check and/or change the CVBC
F26No flame after the ignition phase (5 times in 4 min.)•Detection electrode faut• Check that the electrode is corre positioned and is necessary char it
•Flame instable• Check the burner
•Incorrect valve gas Offset• Check Offset at the minimum
•Flue gas circuit obstructed•Check if flue gas circuit is free
•Siphon obstructed• Check and if necessary change t! siphon
F30Flow sensor fault• Sensor damaged or short circuited• Check the wiring or change the sensor
F31Flow sensor fault• Sensor damaged or wiring broken• Check the wiring or change the sensor
F34Supply voltage under 190V. or over 250V.• Electric mains trouble• Check the electrical system
F35Irregular mains frequency• Electric mains trouble• Check the electrical system
F36Main PCB trouble•Faulty CVBC
•Water on CVBC
• Change the electronic CVBC
F37Incorrect system water pressure•Pressure too low•Fill the system
•Sensor damaged•Check the sensor
F43Return sensor fault• Sensor damaged or wiring shorted• Check the wiring or change the sensor
F44Return sensor fault• Sensor damaged or wiring broken• Check the wiring or change the sensor
F45Flue sensor fault• Sensor damaged or wiring shorted• Check the wiring or change the sensor
F46Flue sensor fault• Sensor damaged or wiring broken• Check the wiring or change the sensor

Ferroli Optimax HE PLUS C  boiler troubleshooting

Fault codeFaultPossible causeCure
A01No burner ignitionNo gasCheck the regular gas flow to the boiler and that the air has been purged from the pipes
Detection or Ignition electrode faultCheck that the electrodes are correctly positioned and free of any deposits
Defective gas valveCheck and change the gas valve
Incorrect inlet gas pressureCheck inlet gas pressure
Siphon obstructedCheck and if necessary change the siphon
A02Flame detected with the burner offIonization electrode defectiveCheck the ionizing electrode wiring
Main board defectiveCheck the PCB
A03High limit protectionFlow temperature sensor not active or correctly locatedCheck the correct positioning and operation of the flow sensor
No system circulationCheck pump and radiator valves present in the system Check operation of the internal by-pass
A04Flue gas faultFault F07 happened 3 times in the last 24 hoursCheck the flue
A05Fan problemTachometer signal interrupted for 1 hour or longerCheck the wiring and the fan
A06No flame after the ignition phase (6 times in 4 minutes)Detection electrode faultCheck that the electrodes are correctly positioned and if necessary change it
Flame unstableCheck the burner
Incorrect valve gas OffsetCheck the Offset at the minimum power
Flue gas circuit obstructedCheck if flue gas circuit is free
Siphon obstructedCheck and if necessary change the siphon
A41Flow sensor disconnectedSensor disconnectedCheck the correct positioning and operation of the flow sensor
F07High fume temperatureThe exchanger probe detects and excessive temperature for over 2 minutesCheck the exchanger
F10Flow sensor faultSensor damaged or short circuited Sensor damaged or wiring brokenCheck the wiring or change the sensor
F11Return sensor faultSensor damaged or v/iring shorted Sensor damaged or wiring brokenCheck the wiring or change the sensor
F12DHW sensor faultSensor damaged Wiring shorted Wiring disconnectedCheck the wiring or replace the sensor
F13Exchanger probe faultSensor damaged or v/iring shorted Sensor damaged or wiring brokenCheck the wiring or replace the probe
F14Flow sensor faultSensor damaged or short circuited Sensor damaged or wiring brokenCheck the wiring or change the sensor
F15Fan problemTachometer signal interrupted, fan connectionCheck the wiring and the fan
Fan damaged, debris in fanCheck the fan. clean debris
F34Supply voltage under 170VElectric supply problemCheck the electrical system
F35Irregular mains frequencyElectric supply problemCheck the electrical system
F37Incorrect system water pressurePressure too lowFill the system
Sensor damagedCheck the sensor
F39External probe faultSensor damaged or short-circuitedCheck the wiring or change the sensor
F42Flow sensor faultSensor damagedChange the sensor

Ferroli PEGASUS F3 N 2S  boiler troubleshooting

ProblemCause/Solutions
After a few attempts at ignition, the electronic controller shuts down the boiler.Pilot light nozzle dirty Clean with compressed air.
Check the regular gas flow to the boiler and the air has been eliminated from the pipes.
Check that the electrodes are correctly positioned and free of any deposits (see fig. 21).
Make sure that the boiler is connected to a good earth connection.
Check the connections to the ignition and ionization electrodes.
The electrodes are not discharging in the ignition phase.Check that the electrodes are correctly positioned and free of any deposits (see fig. 21). Regulation thermostat adjusted too low.
Check the electrical power supply.
Check the connections to the ignition and ionization electrodes.
Check the connections at the electronic flame controller.
Make sure that PHASE and NEUTRAL are not inverted and that the earth contacts are efficient. Check the inlet gas pressure and any open pressure switches.
Reset the safety thermostat.
Reset the fume thermostat.
Make sure the room thermostat is closed.
The burner burns poorly: flames too high, too low or too yellow.Gas valve filter dirty.
Check the gas supply pressure.
Gas nozzles dirty.
Make sure that the boiler is not dirty.
Make sure that ventilation in the room where the unit is located is sufficient for good combustion.
Smell of unburnt gas.Make sure that the boiler is clean.
Check the draught of the flue.
Check that gas consumption is not excessive.
The boiler works but the temperature fails to increase.Check the 2-stage adjustment thermostat works properly.
Check that the operator of the 2nd stage of the gas valve (full power) is supplied (see Fig. 14). Check that gas consumption is not less than that provided for.
Make sure that the boiler is perfectly clean.
Check that the boiler is adequate for the system.
Check that the heating pump is not blocked.
Temperature of the water to the system too high or too low.Check the 2-stage adjustment thermostat works properly.
Check that the pump is not blocked.
Make sure that the characteristics of the circulating pump are adequate for the system.
Burner explosion. Delay on ignition.Check that the gas pressure is sufficient and the boiler casing is not dirty.
The adjustment thermostat switches back on with too great a temperature difference.Check that the thermostat bulb is properly inserted in the sheath.
Check the 2-stage thermostat works properly.
The boiler produces condensation water.Check that the boiler is not operating at too low a temperature (below 50°C).
Check that gas consumption is regular.
Check the efficiency of the flue.
The boiler goes out for no apparent reason.Fume thermostat trips.
Safety thermostat trips due to temperature rise.

Ferroli MODENA 27 C HE  boiler troubleshooting

Fault codeFaultPossible causeCure
A01No burner ignitionNo gasCheck the regular gas flow to the boiler and that the air has been purged from the pipes
Detection or Ignition electrode faultCheck that the electrodes are correctly positioned and free of any deposits
Defective gas valveCheck and change the gas valve
Incorrect inlet gas pressureCheck inlet gas pressure
Siphon obstructedCheck and if necessary change the siphon
A02Flame detected with the burner offIonisation electrode defectiveCheck the ionising electrode wiring
Main board defectiveCheck the PCB
A03High limit protectionFlow temperature sensor not active or correctly locatedCheck the correct positioning and operation of the flow sensor
No system circulationCheck pump and radiator valves present in the system Check operation of the internal by-pass
A04Flue gas faultFault F07 happened 3 times in the last 24 hoursCheck the flue
A05Fan problemTachometer signal interrupted for 1 hour or longerCheck the v/iring and the fan
A06No flame after the ignition phase (6 times in 4 minutes)Detection electrode faultCheck that the electrodes are correctly positioned and if necessary change it
Flame unstableCheck the burner
Incorrect valve gas OffsetCheck the Offset at the minimum power
Flue gas circuit obstructedCheck if flue gas circuit is free
Siphon obstructedCheck and if necessary change the siphon
A41Flow sensor disconnectedSensor disconnectedCheck the correct positioning and operation of the flow sensor
A42Flow sensor faultSensor damagedChange the sensor
F07High fume temperatureThe exchanger probe detects and excessive temperature for over 2 minutesCheck the exchanger
F10Flow sensor faultSensor damaged or short circuitedCheck the wiring or change the sensor
Sensor damaged or wiring broken
F11Return sensor faultSensor damaged or wiring shortedCheck the wiring or change the sensor
Sensor damaged or wiring broken
F12DHW sensor faultSensor damagedCheck the v/iring or replace the sensor
Wiring shorted
Wiring disconnected
F13Exchanger probe faultSensor damaged or wiring shortedCheck the wiring or replace the probe
Sensor damaged or wring broken
F14Flow sensor faultSensor damaged or short circuitedCheck the wiring or change the sensor
Sensor damaged or wring broken
F15Fan problemTachometer signal interrupted, fan connectionCheck the v/iring and the fan
Fan damaged, debris in fanCheck the fan. dean debris
F34Supply voltage under 170 VElectric supply problemCheck the electrical system
F35Irregular mains frequencyElectric supply problemCheck the electrical system
F37Incorrect system water pressurePressure too lowFill the system
Sensor damagedCheck the sensor
F39External probe faultSensor damaged or short-circuitedCheck the wiring or change the sensor
F43Exchanger protection activation.No system circulationCheck the circulating pump
Air in the systemVent the system
F 52Flow sensor faultSensor damagedChange the sensor
A61Controller ABM03A faultController ABM03A internal errorCheck the earth connection and replace the controller if necessary.
A62No communication between controller and gas valveController not connectedConnect the controller to the gas valve
Valve damagedReplace the valve
A63, A64, F66
Controller ABM03A faultController ABM03A internal errorCheck the earth connection and replace the controller if necessary.

Ferroli Optimax 25 C  boiler troubleshooting

FaultPossible causeCure
F1No burner ignition• No gas• Check the regular gas flow to the boiler and the air has been purged from the pipes.
• Detection or ignition electrode fault• Check that the electrodes are correctly positioned and free of any deposits
• Defective gas valve• Check and change the gas valve
• Incorrect inlet gas pressure• Check inlet gas pressure
• Siphon obstructed• Check and if necessary change the siphon
F2flame detected with the burner off• Ionisation electrode defected• Check the ionizing electrode wiring
• Main board defected• Check the CVBC
F3100°C Safety thermostat trips• Flow sensor not active or correctly located• Check the correct positioning and operation of the flow sensor
• No system circulation• Check the pump and radiator valves present in the system
F5Fan problem• Tachometer signal interrupted, fan connection• Check the wiring and fan
• Fan damaged, debris in fan• Check the fan, clean debris
F8No flame after the ignition phase• CVBC fault• Check and if necessary change the CVBC
• Ionisation probe fault• Change/clean ionisation probe
• Mains interference• Check the earthing
F9No communication between the CVBC and the gas valve• Incorrect wiring• Check the wiring
• Damaged valve• Check the CVBC
• Change the valve
F10 - F22Microprocessor trouble• Microprocessor operating trouble• Cut off and restore the electricity supply. If the trouble remains, check and/or change the main PCB