27
Regulation and servicing
for the technician
Changing Gas type
ATTENTION: the operations described below must be carried out only by qualified
personnel
[authorized from HERMANN Ltd]
.
For gas conversion, use the nozzles supplied by boiler manufacturer only.
Using LPG, it is absolutely necessary to install a pressure reducer upstream the boiler.
1. Disconnect the boiler from the electrical supply.
2. gain access to the main PCB and move the jumper CM2 to the suitable gas position:
MET
for
Natural gas (G20),
GPL
for
Buthane (G30)
or
Propane (G31)
3. Check that pressure and gas input are enough to guarantee the correct functioning of the
appliance.
4. On “SE” models, open sealed combustion chamber.
5. Remove pipe between gas valve and injectors bar.
6. Remove injectors bar and replace the nozzles with the
ones suitable for the available gas type, using a 7 mm.
spanner (see figure “BURNER”). Reassemble injectors
bar and pipe, replacing gaskets. Check, with burner ON,
that there are no gas leaks. On “SE” models, close sealed
combustion chamber;
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7
7. Check, with burner ON, that there are no gas leaks and that the pressure upstream the boiler
is:
Natural gas
: min.17 – max. 25 mbar
Buthane
: min. 25 – max 35 mbar
Propane
: min. 25 – max 37 mbar
8. Repeat the gas valve MAX-MIN pressure regulation, carefully following the instructions described
in the previous pages.
9. Check that there are no gas leaks.
10. apply the sticker indicating the type of gas (supplied with the kit) on the suitable area on “WARN-
ING” label inside the boiler.
BURNER
