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9
Gas setting
Ex-factory the appliances are preset to nominal capacity
and a nozzle pressure of 15.0.
(Natural gas H, Wo = 15.0 kWh/m³)
Attention should be paid to capacity shortage in
the event of low Wobbe index.
9.1 Appliance check
– If the appliance type does not comply with the locally
available type of gas, adjustment to the available type
of gas should be carried out. (see Chapter 9.6).
– Check correspondence of the Wobbe-index Wo of the
locally available type of gas with the ex-factory preset
Wobbe-index Wo and adjust gas setting if necessary
to applicable heat requirement according to DIN 4701.
9.2 Gas setting according to air vent pressure
method
– Shut stopcock in main gas supply to boiler unit.
– Release screw in measure device joint of the output
pressure (see Fig. 6, pos. 3) and connect U-tube
manometer.
– Open stopcock in main gas supply to boiler unit and
ignite boiler.
– Set "auto/man/TÜV"-switch of the weather-sensitive
heating circuit control unit (if present) to "man" (see
Fig. 10, pos. 2).
– Compare nozzle pressure with table value (see gas
setting table) for nominal capacity.
– If necessary adjust the nozzle pressure with the gas
adjusting screw (see Fig. 6, pos. 4).
In order to be able to adjust the nozzle pressure, first
remove the cover screw. Only then will the nozzle
pressure adjusting screw become accessible. Clockwise
revolution will effect pressure increase. The valve
responds extremely sensitively to the revolution of the
adjusting screw. Therefore it should be adjusted only in
minute steps.
Before going to the next step wait for approx. 5 seconds
for the new nozzle pressure to have stabilised. Replace
and secure the cover screw on completion of the
foregoing procedure.
A
1
4
5
2
3
9.3 Gas setting according to volumetric
method
(only natural gas)
– Carry out counter check.
– Carry out flow rate check based on the gas settings
table.
If deviations do not exceed ± 5% adjustment will not be
required.
If deviations are between - 5% and - 10%:
Adjust the nozzle pressure and consequently also the
flow rate (see Chapter 9.2)
If deviations are over + 5% and below - 10%:
Check settings and if no errors in the nozzle pressure
settings can be detected, contact your gas supplier.