vents must be made on the outside
walls for which the surface area must
never be less than 3,000 cm
2
and
5,000 cm
2
for gas with a density gre-
ater than 0.8.
2.1.1 Handling
Once the boiler is in its place of instal-
lation and the packaging has been
removed, proceed as follows if it must
be moved (fig. 3/a):
– remove the casing cover;
– attach the lifting brackets (located
on the rear of the boiler) and fasten
it in place with the screws provided;
– insert two 3/4” pipes in the holes in
the brackets, lift the boiler carefully
and place into position.
2.2 CONNECTING
UP SYSTEM
Before proceeding to connect up the
boiler, you are recommended to make
the water circulating in the piping in
order to eliminate any foreign bodies
that might be detrimental to the ope-
rating efficiency of the appliance.
The unit must be connected up with
rigid pipe fittings which will not subject
it to stress of any kind.
The connections should be easy to
disconnect using pipe unions with
orientable connections. You are
recommended to install suitable shu-
toff valves on the system flow and
return pipes.
In order to achieve a good water
distribution inside the cast-iron body,
the system flow and return pipes
should be connected to the same side
of the boiler.
The boiler comes supplied standard
with the attachments on the right-
hand side, with the possibility of them
being transferred to the left-hand
side.
In that case, move the water distribu-
tor, located on the return header, and
the thermostat bulbs located in the
sheathe, to the same side.
The thermal jump between the
system flow and return pipes should
not exceed 20°C. For this purpose, it
is advisable to install a mixer valve
with corresponding anti-condensation
pump.
CAUTION: The system circulation
pump or pumps must go into action
at the time of boiler ignition.
For this purpose, you are recommen-
ded to use an automatic system of
precedence.
The gas connection must be
made using seamless steel pipe
(Mannesmann type), galvanized and
with threaded joints provided with
gaskets, excluding three-piece con-
nections, except for initial and end
connections.
Where the piping has to pass throu-
gh walls, a suitable insulating sleeve
must be provided.
When sizing gas piping, from the meter
to the boiler, take into account both
the volume flow rates (consumption)
in m
3
/h and the relative density of the
gas in question.
The sections of the piping making up
the system must be such as to gua-
rantee a supply of gas sufficient to
cover the maximum demand, limiting
pressure loss between the gas meter
and any apparatus being used to not
greater than:
– 1.0 mbar for family II gases (natural
gas);
– 2.0 mbar for family III gases (butane
or propane).
An adhesive data plate is sticked insi-
de the front panel; it contains all the
technical data identifying the boiler
and the type of gas for which the boiler
is arranged.
2.3 CHARACTERISTICS
OF FEEDWATER
It is absolutely essential that the water
used for the central heating system
should be treated in the following
cases:
– Very extensive systems (with high
contents of feedwater).
– Frequent addition of makeup water
into the system.
– Should it be necessary to empty the
system either partially or totally.
2.3.1 Filter on the gas pipe
The gas valve is supplied ex factory
with an inlet filter, which, however, is
not adequate to entrap all the impu-
rities in the gas or in gas main pipes.
To prevent malfunctioning of the valve,
or in certain cases even to cut out the
safety device with which the valve is
equipped, install an adequate filter on
the gas pipe.
2.4 SYSTEM FILLING
Filling must be done slowly so as to
allow any air bubbles to be bled off
through the air vents provided on the
heating system.
The pressure of cold charging of the
system, and the pressure of pre-
pressurization of the expansion ves-
sel, must correspond, or in any case
must not be less than, the height of
the static column of the system (e.g.,
for a static column of 5 m, the pre-
pressurization pressure of the expan-
sion vessel and the charging pressure
must correspond to at least 0.5 bar).
2.5 CONNECTING UP FLUE
The flue for the atmospherical expul-
sion of the combustion products from
natural draught appliances must meet
the following requirements:
6
Fig. 3/a
