2
INSTALLATION
2.1
BOILER ROOM
The boiler room should feature all the
characteristics required by standards
governing liquid fuel heating systems.
2.2
BOILER ROOM DIMENSIONS
Position the boiler body on the founda-
tion bed, which should be at least 10
cm high.
The body should rest on a surface
allowing shifting, possibly by means
of sheet metal. Leave a clearance
between the boiler and the wall of at
least 0.60 m, and between the top of
the casing and the ceiling of 1 m (0.50
m in the case of boilers with incorpo-
rated D.H.W. tank).
The ceiling height of the boiler room
should be less than 2.5 m.
2.3
CONNECTING UP SYSTEM
When connecting up the water supply
to the boiler, make sure that the spec-
ifications given in fig. 1 are observed.
All connecting unions should be easy
to disconnect by means of tightening
rings. A closed expansion tank system
must be used.
2.3.1 Accessories (fig. 2)
To ensure boiler efficiency, and a
pressure relief valve set to 3 bar (14)
and a hydrometer to check the system
pressure (16).
Install a pressure relief valve calibrat-
ed to 6 bar (7) on the boiler water out-
let pipe to prevent the risk of bursting
due to excess pressure build up. If the
boiler safety valve cuts in frequently,
install a 5-litre expansion vessel (15)
with maximum operating pressure of
8 bar on the hot water circuit. The
tank should be fitted with a natural
rubber food-grade diaphragm. The
central heating circuit pump (4) can
be installed at the rear of the boiler in
place of the connection union 1" pos.
3 fig. 4/a (we suggest you mount the
pump without the GRUNDFOS UPS
15-50 air degasser).
2.3.2 Filling the water system
Before connecting the boiler, thor-
oughly flush the system to eliminate
scale which could damage the appli-
ance.
Filling must be done slowly so as to
allow any air bubbles to be bled off
through the air valves.
In closed-circuit heating systems, the
cold water filling pressure and the
pre-charging pressure of the expan-
sion vessel should be no less than or
equal to the height of the water head
of the installation (e.g. for water head
of 5 meters, the vessel pre-charging
pressure and installation filling pres-
sure should be at least 0.5 bar).
2.3.3 D.H.W. production
During the preparation of hot water,
the circulating pump installed on
the boiler circuit remains in opera-
tion until the boiler thermostat probe
detects the pre-selected value.
Once the boiler thermostat has reach
the set point, and the selector has
been set to winter operation with the
room thermostat on demand, the cen-
tral heating circuit pump (not sup-
plied) can be actuated.
All residual air in the boiler coils
must be bled at the first start-up to
ensure proper operation.
To facilitate this operation, position
the slot of the release screw on the
check valve horizontally (6 fig. 2).
Once the air has been bled, return the
screw to its original position.
Hot water for sanitary use is prepared
by the boiler in AISI 316L stainless ste-
el, which is fitted with a special spiral-
shaped stainless steel heat exchan-
ger, a magnesium anode to protect
the boiler and an inspection flange to
simplify checking and cleaning.
2.3.4 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 de-
vices should be installed. To prevent
lime scale or deposits on the primary
exchanger, the water used to supply
the heating circuit should must be tre-
ated in accordance with UNI-CTI 8065
standards.
The water used for the central heating
system should be treated in the fol-
lowing cases:
– For extensive systems (with high
contents of water).
– Frequent addition of water into the
system.
– Should it be necessary to empty the
system either partially or totally.
2.4 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 conse-
quent formation of soot, condensate
and encrustation.
The flue used to expel combustion
products into the atmosphere must
meet the following requirements:
– be constructed with waterproof
materials, and resistant to smoke
temperature and condensate;
– be of adequate mechanical resil-
ience and of low heat conductivity;
– be perfectly sealed to prevent cool-
ing of the flue itself;
– be as vertical as possible; the ter-
minal section of the flue must be
fitted with a static exhaust device
that ensures constant and efficient
extraction of products generated by
combustion;
– to prevent the wind from creating
pressure zones around the chimney
top greater than the uplift force
of combustion gases, the exhaust
outlet should be at least 0.4 m high-
er than structures adjacent 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
have an internal section 10% great-
er 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
K reduction coefficient for liquid
fuels:
– 0.045 for firewood
– 0.030 for coal
– 0.024 for light oil
– 0.016 for gas
P boiler input in kcal/h
H height of flue in meters, meas-
ured from the flame axis to the
top of the flue reduced by:
– 0.50 m for each change of
direction of the connection
union between boiler and flue;
– 1.00 m for each metre of
union itself.
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