2.3. 1
System connection unions
The following optional accessories are avail-
able to facilitate water and gas connection
of the boiler with the heating system:
– codos kit, code 8075408
– cocks kit, code 8091801
– r eplacement wall kit f or t he o t her
makes, code 8093900.
Detailed instructions for assembly of the
unions are provided with the kits.
2.3
CONNECTING UP SYSTEM
Before proceeding to connect up the boi-
ler, you are recommended to make the air
circulating in the piping in order to elimi-
nate any foreign bodies that might be
detrimental to the operating efficiency of
the appliance.
When making the hydraulic connections,
make sure that the dimensions indicated in
fig. 1 are respected.
The discharge pipe of the safety valve
must be connected to a collector funnel
for channelling away any discharge if the
safety valve goes into action.
The gas connection must be made using
seamless steel pipe (Mannesmann type),
galvanized and with threaded joints provi-
ded with gaskets, excluding three-piece con-
nections, except for initial and end connec-
tions. Where the piping has to pass through
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
relative density of the gas in question.
The sections of the piping making up the
system must be such as to guarantee a
supply of gas sufficient to cover the maxi-
mum 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 inside the
Fig. 4
front panel; it contains all the technical data
identifying the boiler and the type of gas for
which the boiler is arranged.
CAUTION: On the "25 OF - 30 OF - 25 BF -
30 BF" models, if water is supplied at a
pressure of more than 4 bar, an appro-
priate pressure reducer must be installed
to prevent damage to the boiler. Sime
shall not be held liable for such damage.
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 impurities 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 equip-
ped, install an adequate filter on the gas pipe.
2.4
CHARACTERISTICS
OF FEEDWATER
It is absolutely essential that the water for
the central heating system is to be treated
in the following cases:
– Very extensive system (with high con-
tents of feedwater).
– Frequent addition of makeup water into
the system.
– Should it be necessary to empty the
system either partially or totally.
2.5
SYSTEM FILLING
The boiler and the heating system are filled
with water as follows:
/h and the
– models "25 OF - 30 OF - 25 BFR - 25
BF - 30 BF": using the fill cock on the
pressure switch valve (2 fig. 5).
– model "25 BFT": using the fill cock (27
fig. 2).
The charge pressure, with the system cold,
must be 1 bar.
Filling must be done slowly so as to allow
any air bubbles to be bled off through the air
valves. Should the pressure have risen well
above the limit expected, discharge the over
KEY
1 D.H.W. inlet-outlet
manifold
2 Filling cock
3 D.H.W. filter
4 Manifold by-pass
5 Water pressure
transducer
6 D.H.W. exchanger
7 Water rate adjuster
8 Microswitches
9 Divertor valve
10 D.H.W. sensor (SS)
11 Breather valve
pressure by opening the pressure-relief
valve. Once the filling has been completed,
close the filling tap.
2.6
FLUE
The flue for the atmospherical expulsion of
the combustion products from natural
draught appliances must meet the following
requirements:
– Be gas-tight to the combustion products,
waterproof and thermally insulated.
– Be built of materials suitable for keep
resisting to normal mechanical stresses,
heat, and the action of combustion pro-
ducts and their possible condensates.
– Follow a vertical path and not present
any throttling throughout its entire
length.
– Be adequately insulated to prevent phe-
nomena of condensation or smokes coo-
ling, in particular if located outside the
building or in unheated ambiences.
– Be set at an adequate distance from
combustible or easily inflammable mate-
rial by means of an air gap or suitable
insulating material.
– Have beneath the mouth of the first
smoke duct a chamber for collecting
solid material and any condensate; the
height of the chamber must be at least
500 mm.
Access to the chamber must be guaran-
teed by means of an opening provided
with an air-tight metal door.
– Have a circular, square, or rectangular
internal cross section; in the case of
square or rectangular sections, the cor-
ners must be rounded off with a radius
of no t less t han 20 mm. However,
hydraulically equivalent cross sections
are allowed.
– Be equipped with a chimney-pot at the
top, which must be outside the so-called
back-flow zone, so as to prevent the for-
mation of back-flow, which prevents free
discharge of the products of combustion
into the atmosphere.
– Be devoid of mechanical means of suc-
tion located at the top of the pipe.
– No overpressure should be present in a
chimney that passes within or close up
to inhabited rooms.
Fig. 5
107