19
INSTALLATION
2.11
System filling and emptying
INSIEME EVO 25
boilers require a filling pipe connected to the
central heating circuit return pipe.
Turn the mains power switch OFF and turn the control panel
function selector to (
0
) before filling or draining the system.
2.11.1
Water quality requirements
The manufacturer recommends the use of water as heat transfer
fluid for the central heating system. A chemical treatment system
must be provided for this water.
The heat transfer fluid (water) for the central heating circuit must
conform to the quality parameters given in the following table:
MINIMUM REFERENCE VALUES
pH
6-8
Electrical conductivity
less than 200 μS/cm (25°C)
Chlorine ions
less than 50 ppm
Sulphuric acid ions
less than 50 ppm
Total iron
less than 0.3 ppm
Alkalinity M
less than 50 ppm
Total hardness
less than 35°F
Sulphur ions
none
Ammonia ions
none
Silicon ions
less than 30 ppm
If the hardness of the water exceeds the value specified in the
table, it is mandatory to install a water softening system.
9
Excessive water softening (leading to a total hardness <
15°F) can cause corrosion in metal parts (pipes and boiler
components). Keep the electrical conductivity of the water
under 200 μS/cm.
0
Do not top up the central heating circuit on a frequent
or continuous basis as this can damage the boiler’s heat
exchanger. The use of automatic topping up systems should
be avoided for this reason.
2.11.2
Filling
RI
− Make sure that the boiler’s drain cock (1) is closed before
you start filling the system.
1
− Open the central heating circuit shut-off cocks and slowly
fill the system until the pressure gauge reads out a value
of
1.5 bar
(cold).
20
100
4
40 60 80
3 2 1
0
0
120
RI
− Close the central heating circuit shut-off cocks.
NOTE The system is de-aerated automatically through the
automatic vent valve.
The water drain hose from the vent valve must be
connected to a proper collection system.
