User`s manual

INSTALLERUSERTECHNICIAN
1414
1.6 Ducting flues.
With a specific “ducting system” it is possible to reuse
existing flues, chimneys and technical slots to
discharge the products of combustion of the boiler.
Ducting requires using ducts declared to be suited
for the purpose by the manufacturer, following the
installation and user instructions, provided by the
manufacturer, and the requirements of the UNI 10845
standard.
1.7 Chimneys/flues.
General notes A chimney/flue used to exhaust
combustion products must be designed as follows:
- ducting must ensure sealing of combustion
products, be waterproof and insulated;
- construction in incombustible material suitable to
resist normal mechanical stress, heat and action
of combustion products or condensation;
- ducting routed vertically without reductions/
throttles;
- adequate insulation to avoid condensation or
cooling of flue gas, in particular if installed outside
the building or in rooms without heating;
- be adequately spaced, or, be fitted with an air jacket
for insulation from zones with combustible and/or
easily flammable materials;
- installation of a solid materials collection unit below
the first flue channel at a height of at least 500mm,
fitted with a metal airtight door;
- designed with an internal circular, square or
rectangular section (in that latter two cases with
rounded angles with a radius no less than 20 mm).
Hydraulically equivalent sections are also admitted;
- installation of a chimney terminal at the top of the
flue in compliance with specifications below; if there
is no chimney terminal, it is anyhow necessary to
comply with standards UNI 10641.
- without mechanical suction devices installed at the
top of the duct;
- in flues routed inside or against inhabited buildings,
there must be no risk of pressure surges.
Chimney caps. These devices are installed on single
or multiple flues. These devices are installed to faci-
litate dispersion of combustion products also in
adverse weather conditions and prevent deposit of
foreign matter. Chimney caps must meet the following
requirements:
- useful output section no less than double that of
the flue/chimney;
- suitably designed to prevent penetration of rain or
snow in the flue/chimney;
- designed to ensure constant exhaust of combustion
products with any direction or angle of wind.
The outlet height, corresponding to the height of the
top of the flue/chimney, regardless of chimney caps,
must be outside the “backflow zone”, to avoid the
risk of counterpressure that prevents the free release
of combustion products into the atmosphere.
Therefore always observe the minimum heights
indicated in the figures in standards UNI 7129.
Positioning the draft terminals. Draft terminals
must:
- be installed on external perimeter walls of the
building;
- be positioned (see figure) according to the
minimum distances specified in current technical
standards; in particular according to paragraph
4.4.2.3 of standard UNI 7129 and subsequent
amendments and integrations.
Fumes exhaust on natural draught appliances in
open top closed environments. In spaces closed
on all sides with open tops (ventilation pits, light wells,
inner courtyards, etc.), direct discharge of fumes is
allowed for natural or forced draught gas appliances
with a heat output from 4 to 35 kW, provided the
specifications of current technical standards are
complied with (UNI 7129 par. 4.7).
1.8 System filling.
Once the boiler is connected, proceed with filling the
system through the filler cock (see figure page 19).
Filling is performed at low speed to ensure release
of air bubbles in the water via the boiler and heating
system vents.
The boiler has a built-in automatic venting valve on
the expansion tank located on the side of the sealed
chamber. Check that the cap is loosened. Open the
vent valves on the radiators.
Close vent valves only when water is delivered.
Close the filling valve when the boiler pressure gauge
indicates approx. 1.2 bar.
N.B.: During these operations, turn on the circulating
pump at intervals by means of the main switch on
the control panel. Vent the circulating pump by
loosening the front cap and keeping the motor running
Retighten the cap afterwards.
1.9 Gas system start-up.
To start up the system proceed as follows:
- open windows and doors;
- avoid presence of sparks or naked flames;