2
INSTALLATION
2. 1
BOILER ROOM
The boilers with a rating of more than
35 kW must be equipped with a tech-
nical room whose dimensions and
requirements correspond to the cur-
rent standards and regulations.
The minimum distance between the
walls of the room and the boiler must
not be less than 0.60 m., while the min-
imum height between the top of the
boiler and the ceiling must be at least 1
m. which can be reduced to 0.50 m.
for boilers with incorporated heaters
(however the minimum height of the
boiler room must not be less than 2,5
m). The boilers with a rating of less
than 35 kW can be installed only in
perfectly air-vented rooms. To circulate
air in the room, air vents must be
made on the outside walls which satisfy
the following requirements:
– Have a total surface area of at least
6 cm
2
for each installed Kw of ther-
mal capacity and however not less
than 100 cm
2
.
– To be situated as close as possible
to the floor, unobstructable and pro-
tected by a grate which does not
reduce the air passage area.
2.2
CONNECTING UP SYSTEM
Before proceeding to connect up the
boiler, you are recommended to make
the water circulate in the piping in
order to eliminate any foreign bodies
that might be detrimental to the oper-
ating efficiency of the appliance. For
connecting up the pipes, make sure to
follow the indications illustrated in fig.
1. The connections should be easy to
disconnect using pipe unions with ori-
entable connections.
The shutoff valve must be connected
to a suitable flow system and return
pipes
2.2. 1 System filling
The boiler and the relative system
must be filled operating on the bearing
tap and the pressure of cold charging
the system must be included between
1 - 1.2 bar. During filling the main
switch should be left open.
Filling must be done slowly so as to
allow any air bubbles to be bled off
through the provided air vents. This
operation can be made easy by posi-
tioning horizontally the incision of the
block screw of the shutoff valve.
Upon completing the filling, put the
screw back to its original position. At
the end of the operation make sure
that the tap is closed (fig. 4).
OPEN
2.2.2 D.H.W. production on
"DUETTO OF/BF"
version
When hot treated water is required in
the "DUETTO OF/BF" version, the
switch which commutes the diverter
valve is immediately inserted supplying
hot water practically at once.
To adjust water flow use the water
pressure gauge flow regulator (fig. 5):
- Turn clockwise and the regulator
reduces water supply consequently
increasing the relevant temperatu-
re.
- Turn counter-clockwise and the
regulator increases water supply
consequently reducing the relevant
temperature.
FLOW
REGOLATORE
REGULATOR
DI PORTATA
2.2.3 Characteristics of feedwater
To prevent lime scale and damage to
the tap water exchanger, the water
supplied should have a hardness of no
more than 20°F.
In all cases the water used should be
tested and adequate treatment devi-
ces should be installed.
To prevent lime scale or deposits on
the primary exchanger, the water used
to supply the heating circuit should
must be treated in accordance with
UNI-CTI 8065 standards. It is absolu-
tely essential that the water is to be
treated in the following cases:
– Very extensive systems (with high
contents of feedwater).
– Frequent addition of makeup water
into the system.
– In case it is necessary to empty the
system either partially or totally.
Fig. 4
2.3
SMOKE EXHAUST
2.3. 1 Connecting up flue
The flue is of fundamental importance
for the proper operation of the boiler;
if not installed in compliance with the
standards, starting the boiler will be
difficult and there will be a consequent
formation of soot, condensation and
encrustation.
A flue therefore must satisfy the fol-
lowing requirements:
– be constructed with waterproof
materials and resistant to smoke
temperature and condensate;
– be of adequate mechanical resilience
and of low heat conductivity;
– be perfectly sealed to prevent cool-
ing of the flue itself:
– be as vertical as possible; the termi-
nal section of the flue must be fitted
with a static exhaust device that
ensures cons t ant and ef ficient
extraction of products generated by
combustion;
– to prevent the wind from creating
pressure zones around the chim-
ney top greater than the uplif t
force of combustion gases, the
exhaust outlet should be at least
0.4 m higher than structures adja-
cent to the stack (including the roof
top) within 8 m;
– have a diameter that is not inferior
to that of the boiler union: square or
rectangular-section flues should
Fig. 5
have an int er nal section 10%
greater than that of the boiler union;
– the useful section of the flue must
conform to the following formula:
P
S = K
√H
S resulting section in cm
2
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