31
4.1
GAS VALVE (fig. 16)
The boiler is supplied as standard with
a gas valve, model SIT 822 NOVAMIX
(fig. 16).
4.2
GAS CONVERSION (fig. 17)
This operation must be performed by
authorised personnel using original
Sime components.
To convert from natural gas to LPG or
vice versa, perform the following ope-
rations
– Close the gas isolation valve.
– Replace the nozzle with OR (1) and gasket
(2) with the one supplied in the kit.
– On completion of the conversion test all gas
connections using suitable leak detection
fluid. Do not use a naked flame.
– Apply the new data plate showing the
correct gas used.
– Re configure PAR 1,as shown in 4.2.1,
and check the combustion performan-
ce as described in 4.2.2.
4.2.1 New fuel configuration
For access to the installer’s parameters,
press simultaneously keys
and
for 5 seconds (3 fig. 12).
The parameters will scroll up and down
with the keys
and
.
The display pane will show the values
of the parameter PAR 1. If the boiler is
a methane (G20) model, SET 7 will be
displayed:
To change the fuel to propane (G31), it is
necessary to set SET 15, by pressing the
key
.
The standard display will automatically
return after 10 seconds.
The table below shows the SET settings
to enter when the type of gas fuel is
changed.
GAS
BOILER
PAR 1
-
1
-
2
NATURAL
-
3
GAS
-
4
(G
20)
-
5
-
6
Single (110 HE I-E)
7
Cascade
8
-
9
-
10
-
11
PROPANE
-
12
(G 31)
-
13
-
14
Single (110 HE I-E)
15
Cascade
16
4.2.2 Calibrating the gas valve
pressures
Measure the CO2 values with a combu-
stion analyser.
Sequence of operations:
1)
Press and hold the button down for a
few seconds
.
2)
Press the button for a few seconds
.
3)
Identify the CO2 values at max. power
by adjusting the shutter (5 fig. 16):
MAX power
CO
2
(Methane)
CO
2
(Propane)
9,0 ±0,3
10,2 ±0,3
4)
Press the button for a few seconds
.
5)
Identify the CO2 values at min. power
by adjusting the OFF-SET regulation
screw (6 fig. 16):
MIN power
CO
2
(Methane)
CO
2
(Propane)
9,0 ±0,3
10,2 ±0,3
6)
Press the buttons several times to
check the pressures
and
change them if required.
7)
Press the button
once more to
quit the function.
4.3
CO / CO2 RATIO
CO ppm
100
400
CO2 %
NG 9%
0,0011
0,0044
LPG 10%
0,0010
0,0040
EV1
EV2
1
2
5
6
Fig. 16
KEY
1
Inlet pressure intake
2
Outlet pressure intake
5 Capacity
step
6 OFF-SET
2
1
Fig. 17
