Operating Conditions; Fuels; Combustion Air; Filling The Installation And Water Quality - Ygnis VARJET Serie Manual Tecnico

7 Operating conditions

7.1 Fuels

The boiler is designed to operate with domestic fuel oil and natural gas.
The use of other fuels such as biogas is only allowed with the express authorisation of the
manufacturer.

7.2 Combustion air

The combustion air must not have high dust concentrations.
It must be also be free of halogens (chlorine, fluorine compounds). An excessive presence
of halogens in the air leads to significant corrosion. Ensure that paint, thinners,
detergents, degreasers and solvents, chlorine bottles, etc. are not stored in the boiler
room.

7.3 Filling the installation and water quality

Rinse and check the watertightness of the whole installation.
Before definitive filling of the installation, it must be thoroughly washed.
Check the water quality using the indicative values stated in chapter 4.2 for each filling. Poor water quality
causes the formation of scale and corrosion in heating installations. Correctly treated water also permits an
increase in lifetime, safety of operation and profitability.
During filling, do not operate the circulating pump, open all the bleed valves on the installation and on the boiler
(heater unit and condenser) to let out the air contained in the pipes. Add water until the hydraulic circuit pressure
is sufficient.

7.4 Protection against corrosion

Generally, correctly implemented installations operated in accordance with the present instructions do not
present corrosion problems, so making the use of chemical additives unnecessary. However, in the event of poor
water quality or infiltration of oxygen from the air into the heating system (open expansion tanks,
expansion/discharge tanks too small, PER tubes without anti-oxygen barrier in the underfloor heating case) a risk
of damage cannot be excluded.
If the heat transfer fluid must be subject to treatment or the addition of antifreeze, it is necessary to check the
correct dosage, the effectiveness, harmlessness and above all the compatibility with the different materials that
make up the installation. In this case annual checks of the quality of water used in the heating installation must
be done by a specialised company to avoid any damage.

7.5 Required operating mode

The maximum operating pressure and the maximum temperature to be complied with are stated on the
identification plate. The maximum and minimum operating temperatures are stated in chapter 4.1.
After cold starting it is strongly recommended to ensure operation for several hours, which allows evaporation of
the condensates inevitably formed in the combustion chamber in this phase.
For a four-connection boiler configuration, comply with the minimum flow rate in the condenser.
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