Filling The Condensate Siphon; Switching The Product On And Off; Preventing Low Water Pressure; Flushing The Heating Installation For The First Time ("Cold") - Vaillant ecoTEC sustain 24 Installation And Maintenance Instructions Manual

9.3

Filling the condensate siphon

C
1. Unclip the lower section of the siphon (1) from the up-
per section of the siphon (2) without removing the pro-
duct's front casing.
2. Remove the float (3).
3. Fill the lower section of the siphon with water up to 10
mm below the upper edge of the condensate discharge
pipe.
4. Re-insert the float (3).
Note
Check that the float is present in the con-
densate siphon.
5. Clip the lower section of the siphon (1) into the upper
section of the siphon (2).
9.4

Switching the product on and off

▶
Press the on/off button on the product.
◁
The display shows the basic display.
9.5

Preventing low water pressure

The required filling pressure is between 0.08 and 0.2 MPa
(0.8 and 2 bar).
If the water pressure falls below 0.05 MPa (0.5 bar), the
value flashes in the display.
If the water pressure falls below 0.03 MPa (0.3 bar), the
product switches off. The display shows 0.0 bar (0.0 MPa).
Fault F22 is stored in the fault list.
▶
Top up the water in the heating installation to start up the
product again.
◁
The pressure value flashes in the display until a
pressure of 0.05 MPa (0.5 bar) or higher has been
reached.
0020253094_05 ecoTEC sustain Installation and maintenance instructions
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9.6 Flushing the heating installation for the first
time ("cold")
Note
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.
1. Check whether all thermostatic radiator valves and both
service valves on the product are open.
2. Connect a hose to the drain valve that is located at the
lowest position in the heating system.
3. Open the radiator valves and the drain valves so that
the water can drain quickly. Start at the next point in the
installation and open the purging valves on the radiators
so that the contaminated water can completely drain.
4. Close the draining cocks.
5. Refill the heating system with water.
6. Check that the expansion relief valve of the heating
system is functioning correctly by turning the handle
on the valve.
7. Check the pressure in the heating system and top up
with water if necessary.
8. Close the filling valve and the cold water tap.
9.7

Filling and purging the heating installation

1. Flush the heating installation through.
2. Observe the information on the topic of treating
(→ Page 28) heating water.
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3. Undo the cap of the automatic air vent (1) by one to two
rotations and leave it open, as the product purges itself
via the automatic air vent even in continuous operation.
4. Open all thermostatic radiator valves.
5. Supply the heating circuit with water.
6. Check whether the stopcocks for the heating flow and
return are open.
7. Start filling programme P.06.
Check programmes – Overview (→ Page 45)
◁
The prioritising diverter valve is moved to the mid-
position.
8. Fill with water until the required filling pressure is
reached.
–
Recommended filling pressure: 0.8 to 2 bar
◁
The heating and domestic hot water function cannot
be activated.
◁
The pressure value flashes in the display until a
pressure of 0.05 MPa (0.5 bar) or higher has been
reached.
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