46
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 foun-
dation 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 incorporated 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 sup-
ply to the boiler, make sure that
the specifications 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/294
kPa (14) and a hydrometer to check
the system pressure (16).
Install a pressure relief valve cali-
brated to 6 bar/588 kPa (7) on the
boiler water outlet 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/784 kPa on the hot water circuit.
The tank should be fitted with a nat-
ural 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
WILO-YONOS PARA RS 15/6 RKC-
KU air degasser).
2.3.2 Filling the water system
Before connecting the boiler,
thoroughly flush the system to
eliminate scale which could dam-
age the appliance.
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
expansion 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 pressure 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 operation
until the boiler thermostat probe
detects the pre-selected value.
Once the boiler thermostat has
reach the set point, and the selec-
tor has been set to winter opera-
tion with the room thermostat on
demand, the central heating circuit
pump (not supplied) can be actu-
ated.
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 pre-
pared by the boiler in AISI 316L
stainless steel, which is fitted with
a special spiral-shaped stainless
steel heat exchanger, a magnesium
anode to protect the boiler and an in-
spection 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
devices should be installed. To pre-
vent 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.
The water used for the central hea-
ting system should be treated in the
following 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 SMOKE EXHAUST
2.4.1 Connecting up flue
The flue is of fundamental impor-
tance for the proper operation of
the boiler; if not installed in compli-
ance with the standards, starting the
boiler will be difficult and there will
be a consequent 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
cooling 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 effi-
cient extraction of products gen-
erated by combustion;
– to prevent the wind from cre-
ating pressure zones around
the chimney top greater than
the uplift force of combustion
gases, the exhaust outlet should
be at least 0.4 m higher than
structures adjacent to the stack
(including the roof top) within 8
m;
– have a diameter that is not infe-
rior to that of the boiler union:
square or rectangular-section
flues should have an internal sec-
tion 10% greater than that of the
boiler union;
– the useful section of the flue must
conform to the following formula:
S resulting section in cm
2
K reduction coefficient for liquid
fuels:
– 0.045 for firewood
– 0.030 for coal
2 INSTALLATION
P
S = K
√H
