Immergas 3.025499, Instruction And Recomendation Booklet

Page: 47 / 68

47
INS
TALLER
US
ER
MAINTEN
AN
CE TECHNI
CI
AN
3.12 ''CHIMNEY SWEEP'' FUNCTION.
If this function is activated it takes boiler func-
tioning to the adjustable power of the central
heating selector switch. In this state all adjust-
ments are excluded and only the safety thermo-
stat and the limit thermostat remain active. To
activate the chimney sweep function press the
Reset button "C" for 8 to 15 seconds in absence of
domestic hot water and heating requests. Its acti-
vation is signalled by the relative symbol (22 Fig.
2-2). This function allows the technician to check
the combustion parameters. After the checks
deactivate the function, switching the boiler off
and then on again using the Stand-by button.
3.13 PUMP ANTI-LOCK FUNCTION.
The boiler has a function that starts the pump at
least once every 24 hours for the duration of 30
seconds in order to reduce the risk of the pump
becoming blocked due to prolonged inactivity.
3.14 THREE-WAY ANTI-LOCK
FUNCTION.
Both in “domestic hot water” and in “domestic
hot water-central heating” phase the boiler is
equipped with a function that starts the three-
way motorised group 24 hours after it was last
in operation, running it for a full cycle so as to
reduce the risk of the three-way group becoming
blocked due to prolonged inactivity.
3.15 RADIATORS ANTI-FREEZE
FUNCTION.
If the system return water is below 4°C, the boiler
starts up until reaching 42°C.
3.16 BOILER CONTROL PANEL
ELECTRONIC BOARD PERIODIC
SELF-CHECK.
During functioning in central heating mode or
with boiler in standby, the function activates
every 18 hours after the last boiler check/power
supply. In case of functioning in domestic hot wa-
ter mode the self-check starts within 10 minutes
after the end of the withdrawing in progress, for
duration of approx. 10 seconds.
N.B.:
during self-check, the boiler remains off.
3.17 AUTOMATIC VENT FUNCTION.
To activate function “F8” relating to the boiler
circuit press buttons “A and B” at the same time
(Fig. 2-2) for 5 seconds with the boiler in stand-
by. The function consists of the cyclic activation
of the pump (100 s ON, 20 s OFF) and the 3-way
valve (120 s domestic hot water, 120 s central
heating). The function ends after 18 hours or
by switching the boiler on using the ignition
button “ ”.
To activate the thermal system air bleeding, posi-
tion the zone circulator operation mode selector
on the "automatic vent" mode.
3.18 YEARLY APPLIANCE CHECK AND
MAINTENANCE.
The following checks and maintenance should
be performed at least once a year.
- Clean the flue side of the heat exchanger.
- Clean the main burner.
- If deposits are detected in the combustion
chamber one must remove them and clean the
heat exchanger coils using nylon or sorghum
brushes; it is forbidden to use brushes made of
metal or other materials that may damage the
combustion chamber itself.
- Check the integrity of the insulating panels
inside the combustion chamber and if damaged
replace them.
- Visually check for water leaks or oxidation
from/on fittings and traces of condensate
residues inside the sealed chamber.
- Check contents of the condensate drain trap.
- Via the condensate drain cap check that there
are no residues of material that clog condensate
passage; also check that the entire condensate
drain circuit is clear and efficient.
In the event of obstructions (dirt, sediment,
etc.) with consequent leakage of condensate
in the combustion chamber, one must replace
the insulating panels.
- Check that the burner seal gaskets and the lid
are intact and perfectly efficient, otherwise
replace them. In any case the gaskets must be
replaced at least every two years, regardless of
their state of wear.
- Check that the burner is intact, that it has no
deformations or cuts and that it is properly
fixed to the combustion chamber lid; otherwise
it must be replaced.
- Visually check that the water safety valves drain
is not blocked.
- Check, after discharging the system pressure
and bringing it to zero (read on boiler pressure
gauge), that the expansion vessel charge is at 1.0
bar.
- Check that the domestic hot water expansion
vessel charge is at a pressure between 3 and 3.5
bar.
- Check the charge of the solar expansion vessel
according to system requirements.
- Check that the system static pressure (with
system cold and after refilling the system by
means of the filling cock) is between 1 and 1.2
bar.
- Visually check that the safety and control
devices have not been tampered with and/or
shorted, in particular:
- temperature safety thermostat;
- system pressure switch.
- Check the condition and integrity of the electri-
cal system and in particular:
- supply voltage cables must be inside the
fairleads;
- there must be no traces of blackening or
burning.
- Check the cleanliness of the solar collector
glass.
- Check the status of the glycol present in the
solar circuit.
- Control the heat carrying liquid every 2 years
for its antifreeze capacity and pH value.
- Check ignition and operation.
- Check correct calibration of the burner in
domestic hot water and central heating phases.
- Check the operation of the appliance control
and adjustment devices and in particular:
- intervention of the main electrical switch on
the boiler;
- system control thermostat intervention;
- domestic hot water control thermostat inter-
vention.
- Check sealing efficiency of the gas circuit and
the internal system.
- Check the intervention of the device against
no gas ionisation flame control. The relative
intervention time must be less than 10 seconds.
N.B.: in addition to yearly maintenance, one
must also check the thermal system, with fre-
quency and procedures that comply with the
indications of the technical regulations in force.