4.2 Startup
Before lighting the boiler
•
Check the seal of the gas system.
•
Check correct prefilling of the expansion tank.
•
Fill the water system and make sure all air contained in the boiler and the system
has been vented.
•
Make sure there are no water leaks in the system, DHW circuits, connections or boiler.
•
Check correct connection of the electrical system and efficiency of the earthing sys-
tem.
•
Make sure the gas pressure for heating is that required.
•
Make sure there are no flammable liquids or materials in the immediate vicinity of
the boiler
Checks during operation
•
Switch the unit on.
•
Check the tightness of the fuel circuit and water systems.
•
Check the efficiency of the flue and air/fume ducts while the boiler is working.
•
Make sure the water is circulating properly between the boiler and the systems.
•
Make sure the gas valve modulates correctly in the heating and domestic hot water
production stages.
•
Check correct boiler lighting by performing various tests, turning it on and off with
the room thermostat or remote control.
•
Make sure the fuel consumption indicated on the meter matches that given in the
technical data table in cap. 5.
•
Make sure that with no demand for heating, the burner lights correctly on opening a
hot water tap. Check that in heating mode, on opening a hot water tap, the heating
circulating pump stops and there is regular production of hot water.
•
Make sure the parameters are programmed correctly and carry out any required
customisation (compensation curve, power, temperatures, etc.).
4.3 Maintenance
Periodical check
To ensure correct operation of the unit over time, have qualified personnel carry out a
yearly check, providing for the following:
•
The control and safety devices (gas valve, flow meter, thermostats, etc.) must func-
tion correctly.
•
The fume exhaust circuit must be perfectly efficient.
(Sealed chamber boiler: fan, pressure switch, etc. -The sealed chamber must be
tight: seals, cable glands, etc.)
(Open chamber boiler: anti-backflow device, fume thermostat, etc.)
•
The air-fume end piece and ducts must be free of obstructions and leaks
•
The burner and exchanger must be clean and free of deposits. For possible cleaning
do not use chemical products or wire brushes.
•
The electrode must be properly positioned and free of scale.
=
=
fig. 20 - Electrode positioning
•
The gas and water systems must be airtight.
•
The water pressure in the cold water system must be about 1 bar; otherwise, bring
it to that value.
•
The circulating pump must not be blocked.
•
The expansion tank must be filled.
•
The gas flow and pressure must correspond to that given in the respective tables.
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.
18
EN
List of faults
Table. 9
Code
Fault
fault
A01
No burner ignition
Flame present signal with
A02
burner off
Overtemperature protection
A03
activation
F04
Card parameter fault
Card parameter fault
F05
Fan fault
No flame after the ignition
A06
phase
F07
Card parameter fault
A09
Gas valve fault
F10
Delivery sensor 1 fault
F11
DHW sensor fault
F14
Delivery sensor 2 fault
A16
Gas valve fault
F20
Combustion control fault
A21
Poor combustion fault
A23
Card parameter fault
A24
Card parameter fault
F34
Supply voltage under 180V. Electric mains trouble
F35
Faulty mains frequency
Incorrect system water
F37
pressure
F39
External probe fault
A41
Sensor positioning
F42
Heating sensor fault
F43
Exchanger protection trips.
F50
Gas valve fault
A51
Poor combustion fault
cod. 3541D110 - Rev. 02 - 03/2018
FL LOW NOX 24 MCS
Possible cause
Cure
Check the regular gas flow to the boiler
No gas
and that the air has been eliminated
from the pipes
Check the wiring of the electrode and
Ignition/detection electrode fault
that it is correctly positioned and free
of any deposits
Check the gas valve and replace it if
Faulty gas valve
necessary
Gas valve wiring disconnected
Check the wiring
Ignition power too low
Adjust the ignition power
Electrode fault
Check the ionisation electrode wiring
Card fault
Check the card
Check the correct positioning and
Heating sensor damaged
operation of the heating sensor
No water circulation in the system Check the circulating pump
Air in the system
Vent the system
Check the card parameter and modify
Wrong card parameter setting
it if necessary
Check the card parameter and modify
Wrong card parameter setting
it if necessary
Wiring disconnected
Check the wiring
Defective fan
Check the fan
Card fault
Check the card
Low pressure in the gas system
Check the gas pressure
Burner minimum pressure setting Check the pressures
Check the card parameter and modify
Wrong card parameter setting
it if necessary
Wiring disconnected
Check the wiring
Check the gas valve and replace it if
Faulty gas valve
necessary
Sensor damaged
Wiring shorted
Check the wiring or replace the sensor
Wiring disconnected
Sensor damaged
Wiring shorted
Check the wiring or replace the sensor
Wiring disconnected
Sensor damaged
Wiring shorted
Check the wiring or replace the sensor
Wiring disconnected
Wiring disconnected
Check the wiring
Check the gas valve and replace it if
Faulty gas valve
necessary
Fan fault
Check the fan and fan wiring
Check the baffle and replace it if
Faulty baffle
necessary
Flue not correctly sized or
Check the flue
obstructed
Fault F20 generated 6 times in the
See fault F20
last 10 minutes
Check the card parameter and modify
Wrong card parameter setting
it if necessary
Check the card parameter and modify
Wrong card parameter setting
it if necessary
Check the electrical system
Electric mains trouble
Check the electrical system
Pressure too low
Fill the system
Water pressure switch damaged or
Check the sensor
not connected
Probe damaged or wiring shorted Check the wiring or replace the sensor
Probe disconnected after
Reconnect the external sensor or
activating the sliding temperature
disable the sliding temperature
Delivery sensor or DHW sensor
Check the correct positioning and
detached from the pipe
operation of the sensors
Sensor damaged
Replace the sensor
No H
O system circulation
Check the circulating pump
2
Air in the system
Vent the system
Modulating Operator wiring
Check the wiring
disconnected
Check the gas valve and replace it if
Faulty gas valve
necessary
Inlet/exhaust flue obstruction
Check the flue