44
OUT
IN
1
3
P3
2
P1
12
4
5
36
INS
TALLER
US
ER
MAINTEN
AN
CE TECHNI
CI
AN
3.5 GAS VALVE.
The gas valve
(Fig. 44)
is equipped with function-
ing status signal LED (5), the LEDs are under the
transparent protection cover (4).
Colour
State
Off
Gas valve not powered
Green Gas valve powered and working
Red Gas valve powered and not working
3.6 CONVERTING THE HEAT
GENERATOR TO OTHER TYPES OF
GAS.
If the boiler has to be converted to a different
gas type to that specified on the data nameplate,
request the relative conversion kit for quick and
easy conversion.
The gas conversion operation must be carried out
by an authorised company (e.g. the Authorised
Technical Assistance centre).
To convert to another type of gas the following
operations are required:
- remove the voltage from the appliance;
- replace the nozzle located between the gas pipe
and gas/air mixing sleeve
(Part. 15 Fig. 30)
,
taking care to disconnect the appliance during
this operation;
- apply voltage to the appliance;
- calibrate the number of fan revolutions
(Parag.
3.7)
:
- adjust the correct air/gas ratio
(Parag. 3.8)
;
- seal the gas flow rate devices (if adjusted);
- after completing conversion, apply the sticker,
present in the conversion kit, near the da-
ta-plate. Using an indelible marker pen, delete
the data relative 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 in the indoor unit manual.
3.7 CALIBRATION OF NUMBER OF FAN
REVS.
Attention:
Verification and calibration is neces-
sary, in the case of transformation to other types
of gas, in the extraordinary maintenance phase
with replacement of the PCB air/gas circuit com-
ponents or in the case of installations with fume
extraction systems, with horizontal concentric
pipe measuring more than 1 metre.
The indoor unit heat output is correlated to the
length of the air intake and flue exhaust pipes.
This decreases with the increase of pipe length.
The indoor unit leaves the factory adjusted
for minimum pipe length (1m). It is therefore
necessary, especially in the case of maximum
pipe extension, to check the ∆p gas values after
at least 5 minutes of the burner operating at
nominal heat output, when the temperatures of
the intake air and exhaust flue gas have stabilised.
Adjust the nominal and minimum output in the
domestic hot water and central heating modes
according to the values in the table in the indoor
unit manual using the differential manometers
connected to the ∆p gas pressure points
(Part.
20 and 21 Fig. 30)
.
Enter the configurations menu and regulate the
following parameters
(Par. 3.10)
:
- DHW minimum no. of fan revs “S 00.”;
- DHW maximum no. of fan revs “S 01.”.
Listed below are the default settings featured:
Magis Combo
S 00
G20:
1300 (rpm)
G30:
1300 (rpm)
G31:
1300 (rpm)
S 01
G20:
5100 (rpm)
G30:
4800 (rpm)
G31:
5400 (rpm)
3.8 ADJUSTMENT OF THE AIR-GAS
RATIO.
Calibration of the minimum CO
2
(minimum
central heating power).
Enter the chimney sweep phase without with-
drawing domestic hot water and take the selector
switches to minimum until "0" is seen on the dis-
play. To have an exact value of CO
2
the technician
must insert the sampling probe to the bottom of
the sample point, then check that the CO
2
value
is that specified in the table, otherwise adjust
the screw
(Part. 3 Fig. 44)
(Off-Set adjuster).
To increase the CO
2
value, turn the adjustment
screw (3) in a clockwise direction and vice versa
to decrease it.
Calibration of the maximum CO
2
(nominal
central heating power).
On completion of the adjustment of the mini-
mum CO
2
keeping the chimney sweep function
active, take the heating selector switch to max-
imum (increase the value until “99” is seen on
the display). To have an exact value of CO
2
the
technician must insert the sampling probe to the
Key:
1 - Gas valve inlet pressure point
2 - Gas valve outlet pressure point
3 - Off/Set adjustment screw
4 - Transparent protection cover
5 - Gas valve status signal display
12 - Outlet gas flow rate adjuster
PX 42 gas valve
bottom of the sample point, then check that the
CO
2
value is that specified in the table, otherwise
adjust the screw
(Part. 12 Fig. 44)
(gas flow rate
regulator).
To increase the CO
2
value, turn the adjustment
screw (12) in a clockwise direction and vice versa
to decrease it.
At every adjustment variation on the screw 12
it is necessary to wait for the heat generator to
stabilise itself at the value set (about 30 sec.).
Magis Combo
CO
2
at nominal
output
(central heating)
CO
2
at minimum
output
(central heating)
G 20
9.70% ± 0.2
8.60% ± 0.2
G 30
12.30% ± 0.2
11.20% ± 0.2
G 31
10.70% ± 0.2
10.00% ± 0.2
3.9 CHECKS FOLLOWING
CONVERSION TO ANOTHER TYPE
OF GAS.
After making sure that conversion was carried
out with a nozzle of suitable diameter for the
type of gas used and the settings are made at the
correct pressure, check that the burner flame is
not too high or low and is stable (does not detach
from burner);
N.B.:
all adjustment operations must be carried
out by a qualified technician (e.g. the Authorised
Technical Assistance centre).
