3.4 Troubleshooting
Diagnostics
The boiler is equipped with an advanced self-diagnosis system. In case of a boiler anomaly, the display will flash to-
gether with the fault symbol (detail 22 - fig. 1) indicating the fault code.
There are faults that cause permanent shutdowns (marked with the letter "A"): to restore operation just turn the selector
(detail 3 - fig. 1) to RESET (detail 8 - fig. 1) for 1 second or use the RESET on the Remote Timer Control (optional) if
installed; if the boiler fails to start, it is necessary to eliminate the fault indicated by the operation LEDs.
Other faults cause temporary shutdowns (marked with the letter "F" with operation automatically restored as soon as
the value returns within the boiler's normal operating range.
Table. 5 - Fault list
Fault
Fault
code
A01
No burner ignition
Flame present signal with
A02
burner off
Overtemperature protection
A03
intervention
Air pressure switch (fails to
F05
close contacts within 20 sec.
of fan activation)
A06
No flame after ignition phase
F10
Delivery sensor 1 fault
F11
DHW circuit sensor fault
F14
Delivery sensor 2 fault
Power supply voltage under
F34
170V.
F35
Mains frequency fault
Incorrect system water pres-
F37
sure
F39
External probe fault
54
Possible cause
No gas
Ignition/detection electrode fault
Faulty gas valve
Lighting power too low
Electrode fault
Card fault
Heating sensor damaged
No water circulation in system
Air in system
Air pressure switch contact open
Air pressure switch wiring dis-
connected
Flue not correctly sized or
obstructed
Low pressure in gas system
Burner minimum pressure set-
ting
Sensor damaged
Wiring shorted
Wiring disconnected
Sensor damaged
Wiring shorted
Wiring disconnected
Sensor damaged
Wiring shorted
Wiring disconnected
Electric mains trouble
Electric mains trouble
System empty
Water pressure switch not con-
nected or damaged
Probe damaged or wiring
shorted
Probe disconnected after acti-
vating sliding temperature
cod. 3540F611 - 05/2007 (Rev. 00)
NINFA 24 MCS
Cure
Check the regular gas flow to the boiler and that the
air has been removed from the pipes
Check the wiring of the electrode and that it is cor-
rectly positioned and free of any deposits
Check and replace the gas valve
Adjust the lighting power
Check the ionisation electrode wiring
Check the card
Check correct positioning and operation of the heat-
ing sensor
Check the circulating pump
Vent the system
Check the thermostat
Check the wiring
Replace the flue
Check the gas pressure
Check the pressures
Check the wiring or replace the sensor
Check the wiring or replace the sensor
Check the wiring or replace the sensor
Check the electrical system
Check the electrical system
Fill the system
Check the sensor
Check the wiring or replace the sensor
Reconnect the external probe or disable the sliding
temperature
GB