Vaillant ecoTEC plus VUI Series, Installation And Maintenance Instructions Manual

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0020308121_04 Installation and maintenance instructions
15
7.1.3 Carrying out basic preparation for the
installation
1. Make sure that the existing gas meter is capable of
passing the rate of gas supply required.
2. Consider the maximum heat output given in DHW
mode.
3. Protect the potable water correctly by using a suitable
and approved filling device. Depending on the unit ver-
sion, a filling device is included in the scope of delivery.
4. Install the following components:
–
Draining cocks at the lowest points in the heating
installation (
→
current version of BS 2879)
–
A stopcock on the cold water connection
–
A stopcock in the gas pipe
5. Install the connection pipes such that they are free
from mechanical stress.
6. If you use non-diffusion-tight plastic pipes in the heat-
ing installation, ensure that no air gets into the heat
generator circuit.
7. Only solder connectors if the connectors are not yet
screwed to the service valves.
8. Only carry out work on components once they have
cooled down.
9. Only bend connection pipes if they have not yet been
connected to the product.
10. Flush the heating installation thoroughly before in-
stalling the product.
11. If, during gas leak-tightness tests, you also place the
gas pipes and the gas valve assembly in the product
under pressure, use a max. test pressure of
≤
11 kPa
(110 mbar).
12. If you cannot limit the test pressure to 11 kPa
(110 mbar), close any gas stopcocks that are installed
upstream of the product before you carry out the gas
leak-tightness test.
13. If, during gas leak-tightness tests, you have closed the
gas stopcock that is installed upstream of the product,
relieve the gas line pressure before you open this gas
stopcock.
14. Insulate bare pipes exposed to environmental influ-
ences to protect them from frost using suitable insulat-
ing material.
7.1.4 Pressure maintenance in the heating
installation
Heating installations are sealed systems. Air flows in a sys-
tem's heating circuit are disruptive factors that have negative
effects. To prevent air from getting into the system, excess
pressure is built up against the atmospheric pressure, and
this must be maintained. Excess pressure and temperature
fluctuations in the heating circuit are offset by a diaphragm
expansion vessel.
The product is fitted with a diaphragm expansion vessel.
During the installation, you must check whether the volume
of this diaphragm expansion vessel is sufficient for the heat-
ing installation.
Note
The subsequent check is an approximation
method, which does not replace a detailed
technical design. The result only provides a rough
guide for whether the installed diaphragm expan-
sion vessel with a volume of 10 l is sufficient or
whether an additional external expansion vessel is
required.
The following database is based on the diagram below:
–
Pure heating water without added frost protection
–
Average temperature 55 °C
–
Initial pressure 0.05 MPa (0.5 bar)
–
Final pressure 0.25 MPa (2.5 bar)
2
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
B
A 2 3
4
1
A Expansion vessel
volume in l
B Installed heat output in
kW
1 Underfloor heating
2 Radiators made from
pipes or steel
3 Radiators made from
cast iron
4 Nominal volume of the
installed expansion
vessel
▶
Determine the following values.
–
Installed heat output in kW
–
Heating system: Radiators made from cast iron, radi-
ators made of pipes or steel, or underfloor heating
▶
Starting from the installed heat output in a vertical line
upwards, determine the intersection point with the curve
for the relevant heating system.
◁
If the intersection point lies below the dotted line for
the installed expansion vessel, it may be the case
that no additional external expansion vessel is re-
quired.
◁
If the intersection point lies above the dotted line for
the installed expansion vessel, it is probable that an
additional external expansion vessel is required.
▶
If an external expansion vessel is required for the correct
pressure maintenance in the heating installation, install it
in the heating return as close as possible to the product.