Vaillant TURBOmax Pro 28 Instructions For Installation And Servicing page 40

FUNCTIONAL CHECKS
(COMMISSIONING PART III)
7
Fig. F.3: Functional check
40
6
5
4
3
2
1
I
0
Heating system
Ensure that the power on indicator
is illuminated (1).
Ensure that the maximum radiator
temperature control is turned to the
high position.
Ensure external controls are calling
for heat.
The central heating demand
indicator will illuminate (3).
Providing the boiler has not
achieved its set temperature, and
the anti-cycling control is not
activated, the boiler will start its
lighting sequence. Once the fan
and flue system have proved their
satisfactory operation the fan
operation indicator (4) will light.
The gas valve will open and
sparking will commence at the
burner. The ignition indicator (5)
will illuminate.
As soon as the burner has ignited
and the flame has been sensed the
flame indicator (6) will illuminate.
By illuminating in this sequence the
indicator lights have demonstrated
correct operation of the boiler for
CH.
Note: Should the boiler fail to light it
will attempt 2 re-ignition sequences,
if the boiler still fails to light the
burner lock out indicator will
illuminate (7). This usually means
that the gas supply is turned off or
has not been purged of air. Check
the gas supply, push the reset button
and repeat the lightning procedure.