DOMIcondens F 24 D - F 28 D
36
EN
cod. 3541C751 - Rev. 00 - 10/2013
4.4 Troubleshooting
Diagnostics
The boiler is equipped with an advanced self-diagnosis system. In case of a boiler fault,
the display will flash together with the fault symbol (detail 11 - fig. 1) indicating the fault
code.
There are faults that cause permanent shutdown (marked with the letter "
A
"): to restore
operation, press the RESET button (detail 6 - fig. 1) for 1 second or RESET on the op-
tional remote timer control if installed; if the boiler fails to start, it is necessary to eliminate
the fault.
Faults marked with the letter "
F
" cause temporary shutdowns that are automatically reset
as soon as the value returns within the boiler's normal working range.
List of faults
Table. 5
Fault
code
Fault
Possible cause
Cure
A01
No burner ignition
Excessive condensate level
Empty / clean the trap
No gas
Check the regular gas flow to the
boiler and that the air has been elimi-
nated from the pipes
Ignition/detection electrode fault
Check the wiring of the electrode and
that it is correctly positioned and free
of any deposits
Faulty gas valve
Check the gas valve and replace it if
necessary
Gas valve wiring disconnected
Check the wiring
Ignition power too low
Adjust the ignition power
A02
Flame present signal with
burner off
Electrode fault
Check the ionisation electrode wiring
Card fault
Check the card
A03
Overtemperature protec-
tion activation
Heating sensor damaged
Check the correct positioning and
operation of the heating sensor
No water circulation in the system Check the circulating pump
Air in the system
Vent the system
F04
Fume thermostat fault
Exchangers dirty (clogged on
water side)
Clean the exchangers
Anomalous water circulation
Fume thermostat contact open
Check the thermostat
Wiring disconnected
Check the wiring
F05
Card parameter fault
Wrong card parameter setting
Check the card parameter and modify
it if necessary
Fan fault
Wiring disconnected
Check the wiring
Faulty fan
Check the fan
Card fault
Check the card
A06
No flame after the ignition
phase
Low pressure in the gas system
Check the gas pressure
Burner minimum pressure setting Check the pressures
F07
Card parameter fault
Wrong card parameter setting
Check the card parameter and modify
it if necessary
A09
Gas valve fault
Wiring disconnected
Check the wiring
Faulty gas valve
Check the gas valve and replace it if
necessary
F10
Delivery sensor 1 fault
Sensor damaged
Check the wiring or replace the sen-
sor
Wiring shorted
Wiring disconnected
F11
DHW sensor fault
Sensor damaged
Check the wiring or replace the sen-
sor
Wiring shorted
Wiring disconnected
F14
Delivery sensor 2 fault
Sensor damaged
Check the wiring or replace the sen-
sor
Wiring shorted
Wiring disconnected
A16
Gas valve fault
Wiring disconnected
Check the wiring
Faulty gas valve
Check the gas valve and replace it if
necessary
F20
Combustion control fault
Fan fault
Check the fan and fan wiring
Faulty baffle
Check the baffle and replace it if nec-
essary
Flue obstructed or not correctly
sized
Check the flue
A21
Poor combustion fault
Fault F20 generated 6 times in the
last 10 minutes
See fault F20
A23
Card parameter fault
Wrong card parameter setting
Check the card parameter and modify
it if necessary
A24
Card parameter fault
Wrong card parameter setting
Check the card parameter and modify
it if necessary
F34
Supply voltage under 180V. Electric mains trouble
Check the electrical system
F35
Faulty mains frequency
Electric mains trouble
Check the electrical system
F37
Incorrect system water
pressure
Pressure too low
Fill the system
Water pressure switch damaged
or not connected
Check the sensor
F39
External probe fault
Probe damaged or wiring shorted
Check the wiring or replace the sen-
sor
Probe disconnected after activat-
ing the sliding temperature
Reconnect the external probe or disa-
ble the sliding temperature
A41
Sensor positioning
Delivery sensor or DHW sensor
detached from the pipe
Check the correct positioning and
operation of the sensors
F42
Heating sensor fault
Sensor damaged
Replace the sensor
F43
Exchanger protection acti-
vation.
No system H
2
O circulation
Check the circulating pump
Air in the system
Vent the system
F50
Gas valve fault
Modulating Operator wiring dis-
connected
Check the wiring
Faulty gas valve
Check the gas valve and replace it if
necessary
A51
Poor combustion fault
Inlet/exhaust flue obstruction
Check the flue
Fault
code
Fault
Possible cause
Cure
