Checking Flame Supervision Device - Vaillant ECOmax VUW 236 EH Instructions For Installation And Servicing

(Note: This control ensures that energy
wasteful short-cycling of the boiler
cannot occur, by preventing the boiler
from igniting for a preset period of 5
minutes after central heating opera-
tion. The hot water operation is unaf-
fected by this control and hot water
can be drawn at any time. To tem-
porarily override the anti-cycling con-
trol turn the central heating control to
the `Hot Water only' position and
then back to the `Heating and Hot
Water' position).
By stepping correctly through these
codes the boiler has demonstrated
correct functioning.
To exit from status mode push the right
hand button once. (The display will
now show the primary flow tempera-
ture).
•
Reset the maximum radiator
temperature control to the required
setting according to Section 5.15.
(For further information on how to use
the boiler display refer to Section 8:
Fault Finding).
5.12 Checking flame super-
vision device
Operate boiler and turn off gas supply
at boiler gas service valve. The boiler
should attempt to relight (sparking at
ignition electrode visible through vie-
wing window) for approximately
10 seconds before shutting down.
Fault code F.21 will then be displayed
on the control panel display. Open
the gas service valve and press the
reset button (10, fig. 36). The boiler
should now relight.
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