you want to ad just the maximum capaci-
ty of the boiler to the requirements of
the thermal system, search for the pres-
sure as indicated on the diagram shown
in fig. 13.
– If using LPG (G30/G31), the maximum
pr essur e nut (1 f ig. 11/a) mus t be
screwed in almost as far as it will go to
turn off gas valve regulation. Adjust the
r egulat or ups tr eam of the boiler t o
obtain the required supply pressure
(point 1.3) and therefore maximum burn-
er pressure.
– Regulate the minimum pressure only
after having adjusted the maximum one.
– Turn off the supply power to the modulator.
– Turn the screw (2) in order to search for
the minimum pressure indicted in
Table 3
.
– Turn the boiler on and off several times
in order to check that the maximum and
minimum pressure corresponds to the
preset values; correct the regulations if
required.
– Adjust, and make sure that you have
restored the power to the modulator.
– Put the pipe back on the valve VENT
pressure test point.
– Remove the manometer, remembering
to tighten the screw for closing the pres-
sure test point (4 fig. 11).
– Put the plastic cap (3) back on the modu-
lator and seal with a drop of coloured
sealant if necessary.
4.4
CLEANING AND
MAINTENANCE
Scheduled maintenance of the generator
is carried out each year by qualified person-
nel. Follow the procedure listed below:
– Clean the gaps of the boiler casing by
moving the relevant swab up and down
inside the gaps.
– Clean the principal burner and wipe the
scale off from the electrodes.
– Check t he combus tion pr oduct dis-
charge system.
– Check appliance start-up, shutdown and
operation.
– After assembly, all the gas connections
mus t be seal t es t ed by using soapy
water or any other suitable product,
avoiding the use of open flames.
4.5
FAULT FINDING
The principal burner does not start.
– Check if power is supplied to the gas valve
enabling device; check its operation and
replace it if required.
– Check flue gas pressure switch operation.
– The fan works but with less revolutions
and therefore it does not enable the flue
gas pressure switch, replace it.
The principal burner does not burn prop-
erly: flame too high, yellow flame.
– Make sure that the gas pressure of the
burner is regular.
– Make sure that the burners are clean.
The boiler works at the maximum C.H.
output.
– Check the calibration value of the heating
pressure.
– Make sure that the coil assembled on
the valve is not interrupted, replace it if
required.
The radiators heat up even during the
summer.
– Check that the check valve seat is free
from impurities.
– Replace the check valve if faulty.
– Assemble a check valve on the system
return pipes.
The radiators do not heat up during the
winter.
– The room stat has been regulated too
low or is faulty and needs to be replaced.
– The electrical connections of the room
stat have not been carried out properly.
– The circulation pump of the system is
stopped, release it.
The safety valve of the boiler intervenes
too often.
– Check that the cold system is not filled
up too high, refer to the recommended
values.
– Check the system valve if it is not-calibrat-
ed replace it.
– Check the expansion vessel pre-inflating
pressure.
– Replace the expansion vessel if needed.
The boiler works but the temperature
does not rise.
– Check that gas consumption is not less
than the one foreseen.
– Make sure that the boiler is clean.
– Make sure that the capacity of the boiler
is suitable for the system.
The fan works but the burner does not
start.
– Check and if needed remove impurities
and condensate from the connection
pipes of the flue gas pressure switch.
– Needs to be calibrated again or even it
will be even better to replace the flue
gas pressure switch with a new one that
has been calibrated in the factory.
The fan does not start.
– Check if the starting motor terminals
are live.
– The electrical winding of the starting
motor is burnt and needs to be replaced.
45
25
20
15
10
21 (18.060)
23 (19.780)
POTENZA TERMICA kW (kcal/h)
PRESSIONE UGELLO mbar
30
35
5
25 (21.500)
31 (26.660)
27 (23.220)
29 (24.940)
G20
Fig. 13
NOZZLE PRESSURE mbar
HEAT OUTPUT kW (kcal/h)
