4 Installation
Installation manual
11
D2CND024A1/4AB + D2TND012~024A4AB
Wall-mounted condensing boiler
3P469346-3N – 2019.11
4.4
To mount the unit
1
The mounting template shows the position for the horizontal
flue. If there is no hole in the wall for the flue piping, drill one. If
there is already a hole in the wall for the flue piping, you can
use this hole as a starting point to determine the position of the
mounting bracket, according to the template. Flue duct must
incline 3° away from the unit, to allow the condensate to drain
back to the boiler.
>3°
200
127
200
DN100
>3°
2
Drill holes for the mounting bracket (Ø10 mm). Fasten the
mounting bracket to the wall according to mounting template.
d=10 mm
3
Hang the unit on the bracket. Make sure the unit is latched to
the bracket.
4.5
Central heating system
requirements
Expansion vessel sizing
The boiler is equipped with an expansion vessel that has initial
charge pressure of 1 bar.
Sufficiency of the incorporated expansion vessel for the central
heating circuit that the boiler is to be connected to depends on
system charge pressure and water temperature circulating in the
circuit.
Determination of system water height and related system charge
pressure are given below:
h
p
≤6 m
0.8 bar
7 m
0.9 bar
8 m
1.0 bar
9 m
1.1 bar
10 m 1.2 bar
11 m
1.3 bar
12 m 1.4 bar
13 m 1.5 bar
h
h
System water height (m)
p
System charge pressure (bar)
In case system charge pressure needs to be more than 1 bar, gas
side initial charge pressure must be increased to the pressure value
that is equal to system charge pressure. Make sure that gas
charging to the vessel is done while boiler and circuit are not
pressurized.
According to the graph below, there is no need to install an
additional expansion vessel for the systems with a water volume in
the area below the operating temperature curve. If water volume is
above the curve, additional vessel must be installed, preferably on
the return to the boiler.
A
System water volume (l)
B
System charge pressure (bar)
*
50°C-40°C temperature regime is given for underfloor
heating systems
Water treatment
Inappropriate central heating circuit water reduces functionality and
efficiency of the boiler over time. Appropriate water should have:
▪ pH degree between 6.5 and 8.5
▪ Hardness less than 15°fH and 8.4°dH
Appropriate additives can be used for water treatment.
If antifreeze is needed for the system, the chosen antifreeze should
not interact with rubber, commercial plastic and metal parts of the
boiler that are in contact with the central heating water.
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