29
11. Now select the option "Fan on?" and confirm with
the '
'-button. The fan will start now. Switch the fan
to maximum speed by selecting this option.
Confirm with the ' '-button. Now press the '
'-button.
Select the option "Service settings" and confirm
with the ' '-button. Press the '
'-button. Select the
option "Pressure settings"; confirm with the ' '-button.
Set the maximum differential pressure at 900 Pa,
using the '
'-button. Confirm with the ' '-button.
Now press several times the '
'-button until you
reach the menu where you can read out the air
differential pressure.
A differential pressure of 900 Pa has to be reached.
If not, check the dimensions of the flue gas discharge
system. Set the maximum differential pressure in the
service level back at the standard level of 840 Pa.
Confirm with the ' '-button. Set the minimum
differential pressure at 110 Pa for the minimum load
of 33%.
12. Check the opening pressure of the gas block.
Connect a pressure differential device to the measu-
ring points pG and pF (see fig. 19 for 7 and 9 sec-
tions and fig. 20 for 11 to 19 sections). Open the
main gas cock (vent the gas line). Disconnect the
ignition device from the ignition electrode.
Press several times the '
'-button, until you reach
the menu with the selecting option "Service settings".
Select this option and confirm with the '
'-button.
Now select "Boiler on?"; confirm with the '
'-button.
The boiler now will make a start attempt without igni-
tion. As soon as the gas valve opens, the opening
pressure can be read out on the pressure differential
device. The ope ning pressure should be bet ween 1
and 3 mbar. When you read out a higher pressure,
turn the N-controller to the left. Repeat point 12 after
resetting the boiler. When the openings pressure lies
between 1 and 3 mbar, a correct presetting is
assured. Connect the ignition device again to the igni-
tion electrode and reset the boiler. Select in the serv-
ice level again the option "Service tests" and confirm
with the '
'-button.
13. The cursor is now placed on option “Boiler on?”.
Press the '
'-button. The control unit will now start
from neutral position. After an internal check and a
check of the differential air pressure, the fan will start.
As soon as the differential air pressure is sufficiently
high, the pre-purge time is started. The fan now pre-
purges for 30 seconds at full load. Then the fan slows
to minimum load. The pre-ignition is activated and the
gas valve opened. If, at the end of the safety time,
there is a sufficient signal from the pilot flame (the
flame is checked with a second ionisation probe) the
boiler will start operating at part load (mi ni mum load).
Gas distribution pipe
Fig. 19 Differential pressure measuring points (boiler with 7 and 9 sections)
blue
black
burner
black
blue
Side view
∆
P gas = PF+PG
∆
P air = PL+PF
Gas multi-block
