Vaillant ecoTEC plus VU GB 5-5 Series Installation And Maintenance Instructions Manual page 13

5.2.1 Connecting the heating flow and heating
return
1. In each case, insert a flat seal into the service valve
(Vaillant accessories).
2. Screw the service valves onto the flow and return con-
nection (1) of the pump group.
3. Screw the service valves to the customer's installation.
–
Diameter of the heating line: 1 1/4"
5.2.2 Installing the expansion vessels
1. Install a sufficiently dimensioned expansion vessel at
the connection in the boiler circuit return (1) and in the
installation circuit.
–
Connection to the pump group: 1/2"
– Large expansion vessel: ≥ 10 l
2. Check that the volumetric capacity of the expansion
vessel in the installation circuit is sufficient for the sys-
tem volume.
0020134823_07 ecoTEC plus Installation and maintenance instructions
1
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5.2.3 Hydraulic connection
Ø 1 1/4"
The manufacturer recommends installing the following com-
ponents in addition to the specified plate heat exchanger for
the hydraulic system separation:
–
A dirt filter installed on the installation side upstream of
the plate heat exchanger
–
Heating-side cleaning connections for backwashing the
plate heat exchanger during maintenance work
To this end, various plate heat exchangers are available
as accessories, depending on the output of a product or
whether it is a cascade system. The pressure loss is ad-
justed to the pump groups that are offered as an access-
ory. The minimum circulation water volume in the unit cir-
cuit is only guaranteed if you use original accessories in the
unit circuit, provided that the maximum pressure losses in
the piping are not exceeded. The manufacturer therefore
urgently recommends that you only install original pump
groups.
Select the plate heat exchanger according to output.
Depending on the unit output, different remaining feed heads
(→ Page 26) are available at the boiler circuit's flow pipe.
Observe the following pressure losses (nominal volume flow
at ΔT=20 K):
Power
< 120 kW
In conjunction with the hydraulic cascade
< 240 kW
< 360 kW
< 480 kW
< 600 kW
< 720 kW
Installation 5
Pressure loss
86 mbar
(0.086 bar)
96 mbar
(0.096 bar)
76 mbar
(0.076 bar)
82 mbar
(0.082 bar)
87 mbar
(0.087 bar)
92 mbar
(0.092 bar)
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