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 supplied)
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 (5 fig. 2).
Once the air has been bled, return
the screw to its original position.
This domestic hot water boiler is of the
rapid accumulation type, made from
vitreous enamelled steel with foam
polyurethane lining, and has a capacity
of 80 litres. The high degree of thermal
insulation drastically reduces heat dis-
persal, thereby cutting boiler mainte-
nance costs.
In the event of especially hard water
(hardness greater than 20÷25 °Fr),
the water should be treated to prevent
build-up of calcium and a subsequent
reduction in heat exchange.
2.3.4 Characteristics of feedwater
The water used for the central heating
system should be treated in the follow-
ing 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 consequent
formation of soot, condensate and
encrustation. The flue used to expel
combustion products into the atmos-
phere must meet the following require-
ments:
– 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 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 out-
let 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 inferior
to that of the boiler union: square or
rectangular-section flues should
have an internal section 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
– 0.024 for light oil
– 0.016 for gas
P
boiler input in kcal/h
H height of flue in meters, mea-
sured 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.
2.5
FITTING THE CASING “AR”
The casing and the control panel are
supplied in separate cardboard pack-
ages. The housing package also con-
tains the boiler documents and the
glass wool for insulating the cast iron
body. To fit the casing, proceed as fol-
lows (fig. 5):
– remove the four screws, then the
burner plate;
– position the glass wool (2), secure
the front panel (3) with the nuts sup-
plied, then refit the burner plate;
– fit the upper (4) and lower (5) brack-
ets to the rear head with the nuts on
the tie rods;
– mount the left (6) and right (7)
sides, fixing the front part of the
sides to the front panel (3) by
means of the pins;
– secure the sides to the upper and
lower brackets by means of the eight
tapping screws;
– secure the two rear panels (8) and
(9) to the sides with the ten tapping
screws supplied;
– secure the front panel (10) to the
sides by means of the pins;
– mount the control panel (11) by
inserting the two lower tabs in the
slots on the sides, then secure with
the tapping screws. Prior to per-
forming the above operation, unwind
the capillary tubes of the two ther-
mostats and of the thermometer by
23
P
S
= K
√
H
Fig. 5
