AL 02 Low water pressure in system
Restore pressure
Check for any leaks in the system
AL 03 High water pressure in system
Empty the system via the drain valve on the
Hydraulic assembly and bring the pressure to approximately 1.2 bar
AL 04 Domestic hot water sensor (SS) fault
Check connections
Replace the sensor
AL 05 Delivery sensor (SM) fault
Check connections
Replace the sensor
AL 06 No flame detection
Check the integrity of the electrode and
Check that it is not grounded
Check gas availability and pressure
Check the operation of the gas valve
AL 07 Safety thermostat (TS) intervention
Check the sensor or thermostat connections
Deaerate the system
Check the bleed valve
Replace the sensor or the thermostat
Check that the pump impeller is not blocked
AL 08 Fault in the flame detection circuit
Check the integrity of the electrode and check that it is not grounded
Check gas availability and pressure
Check the operation of the gas valve
AL 09 No water circulating in the system
Check the rotation of the system pump impeller
Check the electrical connections
Replace the pump
AL 10 Auxiliary sensor fault
Check the hydraulic configuration in the boiler
Check the electrical connection
AL 11 Gas valve modulator disconnected
Check the electrical connection
AL 12 Incorrect configuration of the open / sealed chamber
Set the parameter tS 0.4 (Combustion configuration) to 0
AL 13 Exhaust sensor (SF) intervention
Replace the smoke probe
Contact the Technical Assistance Centre
AL 14 Exhaust sensor (SF) fault
Replace the smoke probe
Check the electrical connection of the smoke probe, if the problem is not resolved, contact the Assistance Centre
AL 15 Fan check cable disconnected
Check the connection cable between the fan and the board
AL 18 Condensate level fault
Check for any clogging in the pipe which takes the condensate to the siphon
Check that the siphon is not clogged
AL 28 Maximum number of consecutive resets reached (6)
Contact the Technical Assistance Centre AL 37 Fault due to low network voltage.
Check with tester
Contact network provider (ENEL)
AL 40 Incorrect supply frequency detected
Contact network provider (ENEL)
AL 41 Flame loss more than 6 consecutive times
Check the detection electrode
Check the gas supply (open valve)
Check mains gas pressure
AL 42 Button fault
Check that buttons are working
AL 43 Open Therm communication fault
Check the electrical connection of the remote control
AL 62 Self-calibrating procedure is required
Carry out the self calibrating procedure (see the specific section)
AL 72 Incorrect positioning of the delivery sensor
Check that the delivery sensor is attached to the delivery pipe
AL 81 Block due to combustion during start-up
Check for blockage in flue
Bleed the air from the gas circuit
AL 83 Irregular combustion (temporary error)
Check for blockage in flue
AL 96 Lockout due to flue (exhaust) blockage
Check for blockage in flue
Additional Functioning Faults
Frequent relief valve intervention
Check circuit pressure
Check expansion vessel
Limited production of domestic hot water
Check the diverter valve
Check that plate heat exchanger is clean
Check domestic hot water circuit valve