Setting The Heating Partial Load; Setting Pump Overrun Time And Pump Operating Mode; Setting The Maximum Flow Temperature; Setting The Return Flow Temperature Control - Vaillant ecoTEC VU Installation And Maintenance Instructions Manual

11.1.1

Setting the heating partial load

The heating partial load of the Vaillant ecoTEC boiler is fac-
tory-set to "auto". This means that the boiler independently
determines the optimum heating output depending on the
current heat demand of the system. A setting is normally
no longer required. If you still want to set a fixed maximum
heating partial load, you can set a value under diagnostic
code "D.000", which equates to the boiler output in kW.
11.1.2 Setting pump overrun time and pump
operating mode
The pump overrun time for the heating mode is set at the
factory to a value of 5 minutes. You can set the pump over-
run time under diagnosis code "D.001" within the range of
1 minute to 60 minutes. You can set a different pump oper-
ating mode under diagnosis code "D.018". Here you have
the choice between 3 = Eco and 1 = Comfort.
Comfort (continuously operating pump)
The internal pump is switched on when the heating flow
temperature is not at "Heating off"(¬ Operating instruc-
tions) and the heating requirement is enabled via an exter-
nal controller.
Eco (intermittently operating pump)
Pump operating mode Eco is the factory setting. This pump
operating mode is useful for removing residual heat after
hot water generation when the heat demand is extremely
low and large temperature spreads exist between the hot
water generation and heating mode target values. This pre-
vents living rooms from being under-supplied. If there is a
heat demand, the pump is switched on every 25 minutes for
5 minutes once the overrun time has elapsed.
11.1.3

Setting the maximum flow temperature

The maximum flow temperature for the heating is set at the
factory to 75 °C. This can be set to a value in the range of
40 °C to 80 °C under diagnosis code "D.071".
11.1.4

Setting the return flow temperature control

If the boiler is connected to an underfloor heating system,
the temperature control can be changed from flow temper-
ature regulation (default setting) to return flow temperature
control under diagnosis code "D.017".
Installation and maintenance instructions ecoTEC 0020173113_01
Adapting the boiler to the heating installation
11.1.5
Setting the burner anti-cycling time
To prevent frequent switching on and off of the burner and
therefore energy loss, an electronic restart lockout is acti-
vated for a specific period each time the burner is switched
off. You can adjust the burner anti-cycling time to the con-
ditions of the heating installation.
The burner anti-cycling time is only activated for the heat-
ing mode.
Hot water handling during a burner anti-cycling time does
not affect the timer.
You can set the maximum burner anti-cycling time at
installer level under diagnosis code "D.002" within the
range 2 minutes to 60 minutes (factory setting: 20 min).
The effective burner anti-cycling time depends on the cur-
rent target flow temperature and the maximum burner anti-
cycling time set.
The effective burner anti-cycling times with respect to the
target flow temperature and the maximum set burner anti-
cycling time can be found in the following table.
i
Reset remaining burner anti-cycling time
> Press the fault clearance key (¬ Operating instruc-
tions).

Burner anti-cycling time

The remaining burner anti-cycling time following
a regular shutdown in heating mode can be
called up under diagnosis code "d.067".
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