Vaillant ECOTEC PLUS VU 80, Installation And Maintenance Instructions Manual

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Establishing operational readiness
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ecoTEC plus installation and maintenance instructions 0020134823_01
9
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Check that both service valves on the boiler are open.
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Slowly open the stop valve on the filling line so that the
water flows into the heating system.
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If the water pressure in the heating system is
too low, the display view switches between fault
message F.22 and the display of the actual pres-
sure when the boiler is switched on.
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Purge the lowest radiator until water flows out of the
purging valve without bubbles.
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Purge all other radiators until the entire heating system
has been filled with water. Close all purging valves.
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Use the display to monitor the rising filling pressure in
the heating installation.
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Top up with water until the pressure gauge display is in
the middle of the grey area and the required filling pres-
sure appears on the display.
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After filling, close the stop valve on the filling line as well
as the cold water valve and remove the filling hose.
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Check all connections and the entire system for leaks.
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Each time the unit is filled and topped up, document this
in a system book.
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Ensure that the filling and drainage tap in the
heating installation is connected to a cold water
valve in accordance with the standard.
9.3.2 Purging the heating installation
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To purge the heating installation, select check pro-
gramme P.0 (
¬ section 11.4 ).
The boiler does not start up, the internal pump operates
intermittently and, as an option, purges the heating circuit
or the hot water circuit. The display shows the filling pres-
sure of the heating installation.
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The filling pressure of the heating installation must not
fall below 0.08 MPa (0.8 bar) when purging is in progress
as, otherwise, this will not be carried out properly.
Check programme P.0 runs for 6.5 minutes.
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Purge all the radiators.
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Then check the water pressure in the heating installation
again.
At the end of the filling procedure, the filling pressure of
the heating installation should be at least 0.02 MPa
(0.2 bar) above the counterpressure of the expansion vessel
("Exp") (P
Installation
P
Exp
+ 0.02 MPa (0.2 bar)).
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If there is still too much air in the heating installation at
the end of check programme P.0, repeat the check pro-
gramme.
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Check all connections for leak-tightness.
9.3.3 Flush the heating installation for the first
time ("cold")
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The complete heating system must be flushed at
least twice: once with cold water and once with
hot water in accordance with the following
instructions.
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Check whether all thermostatic radiator valves and both
service valves on the boiler are open.
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Connect a hose to the drain valve that is located at the
lowest position in the heating system.
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Fully open the radiator valves and drain cocks to ensure
that the water drained quickly. Starting at the top of the
system open the air vents on the radiators to aid com-
plete draining of the contaminated water.
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Close the drain cocks.
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Refill the heating system with water, as described in
(
¬ section 9.3 ).
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Check that the expansion relief valve of the heating sys-
tem is functioning correctly by turning the handle on the
valve.
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Check the pressure in the heating system and top up
with water if necessary.
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Close the filling valve and the cold water valve.
9.4 Preventing low water pressure
To prevent damage to the heating installation that is caused
by low water pressure, the boiler is fitted with a water pres-
sure sensor. If the water pressure falls below 0.1 MPa
(1.0 bar), the boiler indicates low pressure by displaying a
flashing pressure value. If the water pressure falls below
0.05 MPa (0.5 bar), the boiler switches off. The display
shows
F.22 .
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Top up the heating water and switch the boiler on again.
A flashing pressure value appears on the display until a
pressure of 0.11 (1.1 bar) or higher has been reached.
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If you notice frequent drops in pressure, then determine
and eliminate the cause.