Sime FORMAT DGT 25/55, Manual

Page: 78 / 88

78
4.1 D.H.W. PRODUCTION
The preparation of hot water is guaranteed
by the glass storage tank unit with magne-
sium anode for the protection of the boiler
unit and inspection flange for its control and
cleaning.
The magnesium anode must be checked
annually and substituted when it is worn,
pain the forfeiture of the guarantee of the
storage tank.
If the boiler does not produce hot water,
make sure that the air has been released
by pressing on the manual vents after hav-
ing switched off the main switch.
4.2 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. Consequently they must not be
altered. Only when you switch the appliance
from one type of gas supply (methane) to
another (butane or propane), it is permit-
ted to alter the operating pressure.
4.3 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 4.3.1
– For calibrating the maximum and mini-
mum gas pressure values, see point
4.3.2.
– 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.
4.3.1 New fuel configuration
Access the parameters section by pres-
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
25/55 BF 13.2 28.5 36.5 130 165 165 2.2 4.6 4.6 0 0 0
30/55 BF 13.7 28.2 36.2 130 165 165 2.2 4.5 4.5 0 0 0
(*) Max. burner pressure is guaranteed only when the supply pressure exceeds the max. burner pressure by at least 3 mbar.