84
4.1
GAS VALVE (fig. 18)
The boilers are equipped standard with the
SIT 845 SIGMA gas valve (fig. 18).
The gas valve is set at two pressure values:
maximum and minimum.
According to the type of gas burnt, these
correspond to the values given in
Table 4
.
The gas pressures at the maximum and
minimum values, are factory set. Conse-
quently they must not be altered.
Only when you switch the appliance from
one type of gas suppl y (met hane) t o
another (butane or propane), it is permit-
ted to alter the operating pressure.
4.2
GAS CONVERSION (fig. 19)
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 operations (fig.
19):
– Close the gas cock.
– Disassemble the burner manifold (3).
– Replace the main nozzles (6) supplied in
a kit, inserting the copper washer (4).
Use a ø 7 spanner to perform this ope-
ration.
– Configure the new fuel as indicated in
point 4.2.1
– For calibrating the maximum and mini-
mum gas pressure values, see point
4.2.2.
– After have ultimated the conversion of
the boiler, please stick onto the casing
panel the plate showing the relevant fee-
ding gas which is included into the kit.
NOTE: When reassembling components
which you have removed, replace gas
seals; test all gas connections after
assembly using soapy water or a product
made specifically for the purpose, being
sure not to use open flame.
4.2.1
New fuel configuration
Access the parameters section by pres-
sing the control panel keys (
and
) at
the same time for 5 seconds.
The red LED flashes and the display shows:
Scroll the parameters using
or
.
To enter the fuel configuration paramater
PAR 01, use
or
.
The set value
flashes
and if the boiler in
question is a
30 BF
with methane, the
display shows:
4
USE AND MAINTENANCE
3
4
2
1
5
6
Fig. 19
KEY
1 Swivel connection 1/2”
2 Locknut 1/2”
3 Burner manifold
4 Washer ø 6.1
5 Burners
6 Nozzle M6
7 Screw
WARNING: To ensure a perfect
seal, always use the washer (4)
supplied in the kit when replacing
nozzles, even in burner units for
which it is not specified.
Fig. 18
KEY
1
Modulator
2
EV1-EV2 coils
3
Pressure inlet upstream
4
Pressure inlet downstream
5
VENT pressure
TABLE 4
Model
Burner max pressure mbar
Modulator current mA
Burner min pressure mbar Modulator current mA
G20 (*) G30
G31
G20 (*) G30
G31
G20 (*) G30
G31
G20 (*) G30
G31
25 OF
9,1
27,7
35,7
130
165
165
1,6
4,6
4,6
0
0
0
25 BF
13,5
27,9
35,9
130
165
165
1,9
3,7
3,7
0
0
0
30 BF
13,2
26,8
34,8
130
165
165
1,9
4,1
4,1
0
0
0
(*) Max. burner pressure is guaranteed only when the supply pressure exceeds the max. burner pressure by at least 3 mbar.
