User`s manual

INSTALLERUSERTECHNICIAN
2222
reconnect the modulating coil. Boiler minimum heat
output pressure must be not be adjusted to less
than the values given in the tables on page 26
according to the type of gas.
• Adjustment of boiler rated heat output (see figure
on page 23).
N.B.: adjust only after setting minimum pressure
values;
- Turn the domestic hot water temperature knob
(2 page 18) to the maximum setting;
- Open the hot domestic water valve to avoid
modulation;
- Adjust the rated boiler heating power by means
of plastic nut (4), according to maximum pressure
values specified in the tables on page 26
according to the type of gas;
- turn clockwise to increase heating power, and
anticlockwise to decrease.
• Heating power adjustment (see figure on page 23).
Adjust the room heating output by means of the
trimmer (12 page 23) located on the boiler
modulation electronic card, as follows:
- close the domestic hot water cock and turn the
switch (5 page 18) to ( );
- set the heating control selector (1 page 18) to
maximum temperature to prevent modulation;
- adjust heat output by turning the trimmer (12 page
23) on the modulation card, keeping to the values
given in the table on page 26 according to the
type of gas, for boiler variable heat output. Turn
the trimmer clockwise to increase pressure and
counterclockwise to decrease.
N.B.: to adjust the gas valve, remove the plastic
cap (9) and rotate screw (5). Afterwards, refit the
cap and screw.
N.B.: the Avio Maiorboileris equipped with
electronic modulation that adapts boiler power to
actual room heating requirements. Therefore the
boiler operates normally in a variable gas pressure
range between the minimum and maximum heating
power according to the system heat load.
N.B.: the Avio Maior boiler is produced and set to
rated power during heating.
3.7 Zeus Maior slow ignition adjustment.
After setting the minimum and maximum heating
settings for the appliance the first slow ignition step
can be set for the gas valve. Adjust by means of
trimmer (11) on the boiler electronic modulation card.
Rotate clockwise to increase pressure and
counterclockwise to decrease. To obtain slow or
gradual inter-ignition of the burner, we recommend
setting the first step for slow ignition at 25 mm H
2
0
for boilers operating with natural gas and 70 mm
H
2
0 for boilers operating with LPG.
3.4 Converting the boiler to other types of gas.
If the boiler has to be converted to a different gas
type to that specified on the dataplate, request the
relative conversion kit for quick and easy conversion.
Boiler conversion must be carried out by a qualified
technician (e.g. Immergas Technical Assistance
Service).
To convert to another type of gas the following
operations are required:
- main burner nozzle replacement;
- move jumper (13 page 23) to the correct position
for type of gas required (Natural or LPG.);
- adjustment of first slow step of burner ignition;
- adjustment of maximum boiler heating power;
- adjustment of minimum boiler heating power;
- adjust (eventually) heating power;
- seal the gas flow rate regulation devices (if settings
are modified).
- after completing conversion, apply the sticker,
present in the conversion kit, near the dataplate.
Using an indelible marker pen, cancel the data re-
lative to the old type of gas.
These adjustments must be made with reference to
the type of gas used, following that given in the table
on page 26.
3.5 Checks following conversion to other type
of gas.
After ensuring that conversion was carried out with
the required nozzle diameters and that setting is to
the fixed pressure, make sure:
- that there is no flame return in the combustion
chamber;
- that the burner flame is not excessively high or low
and is stable (does not detach from burner);
- the pressure tester used for calibration is perfectly
closed and there are no leaks in the gas circuit.
N.B.: all boiler adjustment operations must be
performed by a skilled technician (e.g. from an
Immergas Technical Services Centre). Adjustment of
the burner must be carried out using a differential
“U” or digital type pressure gauge, connected to the
pressure outlet at the top of the sealed chamber (part
23 page 17) and the outlet pressure socket on the
gas valve outlet (part 6 page 23), with reference to
the pressure value specified in the table on page 26
according to the type of gas to be used with the boiler.
3.6 Zeus Maior adjustments.
• Minimum heating power adjustment (see figure
page 23). The minimum heating power is adjusted
by means of the brass screw (3) on the gas valve;
- turn off the power supply to the modulating coil
(simply detach a faston); turn the screw clockwise
to increase pressure and counterclockwise to
decrease it. On completion of adjustment,