Vaillant ecoTEC plus 937, Instructions And Maintenance Instructions, Page: 37 / 64

37 Installation and maintenance instructions ecoTEC plus 0020031552_03
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Fig. 6.4 Setting range for the storage tank temperature
If the storage tank charging function is switched off the
storage tank is not held at temperature. In this case the
unit switches on when water is drawn off and operates
on a through-flow principle.
H
Danger!
Danger of scalding!
The units are fitted with automatic Legionella
protection control:
If the temperature falls below 50 °C in the hot
water storage tank the storage tank is heated
up to 70 °C once every 24 hours. In such a
case there is a danger of scalding when drawing
the water off.
The Legionella protection control can be de-activated in
the diagnosis level "d.74“.
Activating the storage tank charging
• Switch on the appliance.
• Activate the storage tank charging by turning the hot
water temperature control knob fully clockwise.
The symbol " “ is displayed.
• Turn the hot water temperature control knob to the
temperature you require.
• Press " i " to activate the status indicator.
During the storage tank charging the display shows "S.24“.
Fig. 6.5 Display during storage tank charging
De-activating the storage tank charging
• De-activate the storage tank charging by turning the
hot water temperature control knob fully anti-clockwise.
The symbol " “ disappears.
• Then set the desired hot water temperature. The unit
now operates in the through-flow principle, the stor-
age tank is not held at temperature.
6.1.5 Subsequent flushing through of the heating
system ("hot")
• Allow the appliance to run until both the appliance
and the heating system have reached their operating
temperature.
• Check the heating system for leaks.
• Connect a hose to the drain valve which is located at
the lowest position in the heating system.
• Shut off the appliance, open the drain valve and all
vent valves on the radiators and allow the water to
flow out of the heating system and the combi boiler
quickly and fully.
• Close the drain valve.
• Re-fill the heating system with water as described in
Section 5.4.3.
• Drain water out of the system until a system pressure
of 1.0 bar is reached. (The ideal measured value on the
pressure gauge is 0.5 bar plus an extra amount corre-
sponding to the highest point of the system above the
combi boiler. A height of 10 m corresponds to a pres-
sure increase on the pressure gauge of around 1 bar.
The pressure must not be less than 1 bar on any instal-
lation.)
If the system is to be protected by an inhibitor, it
should be added at this stage in accordance with the
manufacturer's instructions.
Further information can be obtained from Sentinel,
Betz Dearborn Ltd., Tel.: 0151 420 9595, or from Fern-
ox, Alpha–Fry technologies, Tel.: 0870 8700362.
• Re-fit the enclosure of the combi boiler (see Section
5.10).
• Fit the base cover to the combi boiler and shift load
storage tank by pushing the front edge of the cover
into the retaining tag on the front lower edge of the
unit framework.
• Carefully push the base cover upwards until the spring
clips on the side of the unit engage. It may be neces-
Commissioning, Part II: Functional checks 6