Gas Connection; Heating Connection; D Danger; A Caution - Vaillant ecoTEC VU 656/4 Installation And Maintenance Instructions Manual

5 Installation
5.4

Gas connection

Danger!
d
Danger of injury to persons and/or material
damage due to improper installation!
The Vaillant ecoTEC boiler may only be
installed by a recognised skilled trade company
who also assumes the responsibility for proper
installation and initial start-up of the boiler.
The legal directives and the local regulations
for gas supply companies must be observed.
a Caution!
Ensure strainless assembly of the gas pipes to
avoid leakages!
h Note!
Maintain the same gas pipe dimension all the
way to the boiler and avoid reducing the
dimension downstream of the gas meter.
Caution!
a
The gas valve may be damaged if the test
pressure or operating pressure is exceeded!
You must check the tightness of the gas valve
only using a maximum pressure of 110 mbar!
The operating pressure must not exceed
60 mbar!
Fig. 5.9 Fitting the gas connection
The boiler must be connected to your gas pipe via a gas
isolation valve.
• Screw the boiler's gas supply pipe (1) gas-tight with
the gas isolation valve (3, see Fig. 5.10). To do this,
use the R3/4 compression fitting supplied with the
boiler. This is suitable for the connection of a R3/4
gas isolation valve.
• Inspect the gas connection for leakage.
18
5.5
a
The boiler is connected to the heating flow and return
via service valves.
Fig. 5.10 Heating connection
• Fit the flow, return and gas isolation valves (2, 3, 4)
a
1
h

Heating connection

Caution!
Ensure strainless assembly of the supply lines
to avoid leakages in the heating system!
4
including the seals onto the flow, return and gas pipes.
Do not overtighten and ensure the joints are checked
for leaks after fitting.
Caution!
It is essential to use the combined filling and
emptying valve (1) in the return for filling the
boiler without fail, as otherwise the bleeding of
the boiler cannot be ensured. You must
implement the filling in accordance with
standards.
Note!
We recommend the use of seals made of a fibre-
based material similar to cardboard instead of
materials similar to rubber as the latter can
plastically deform and cause pressure losses.
Installation and maintenance instructions ecoTEC 0020029173_01
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