Ariston Benchmark System A 24 RFF, Installation And Servicing Instructions

Page: 33 / 64

33
14. Commissioning and testing
(continued)
14.3 Adjusting the CO
2
Adjustment screw
Fig. 40
14.4 Gas Conversion
To convert from Natural Gas (G20) to LPG (G31), it is
necessary to insert a diaphragm and restrictor between the
gas valve and air/gas arm.
Once the conversion has been made, the CO
2
setting will
need to be checked as described in Section 14.3, for LPG
the CO
2
reading should be 10% +/- 0.2% with the front case
fitted).
To convert from LPG (G31) to Natural Gas (G20), it is
necessary to remove the diaphragm and restrictor from
between the gas valve and air/gas arm.
Once the conversion has been made, the CO
2
setting will
need to be checked as described in Section 14.3, for NG the
CO
2
reading should be 9.2% +/- 0.2% (with the front case
fitted).
14.6 Fitting the external sensor
14.5 Range rating the maximum heating
power
To adjust the maximum heating power it is necessary to
access the settings menu by pressing the and
buttons together for five seconds, and proceed as follows;
1. Press the menu button 3 times to access Menu 4;
2. Press the button to access Menu 4.9;
3. The value is adjustable between 0 and 10, 0 being the
minimum output and 10 being the maximum, please refer
to the chart on page 32 (Fig. 43) for the required setting;
4. The maximum central heating output can now be
adjusted by pressing the setting button ;
5. To exit the setting mode, do not press any buttons for 1
minute, the boiler will automatically exit the Setting Menu.
The external sensor should be fitted 1.5 meters above the
floor on a North to North West facing wall.
To connect the external sensor, it is first necessary to
remove the casing panel as described in Section 18 (page
41);
Remove the PCB cover as described in Section 18.4 and
connect the external sensor as described in Section 18.5
(page 50).
14.3 Adjusting the CO
2
3
6
9
12
Q
Fig. 39
1. Remove the casing panel as described in Section 18.1
(page 41);
2. Connect a manometer to the inlet test nipple on the gas
valve, turn on a hot tap and ensure the inlet working
pressure is 20mbar. If correct proceed as follows;
3. Turn on the combustion analyser, remove the combustion
test point plug Q (Fig. 39) and insert the analyser probe
into the test point;
4. Turn on a hot tap and ensure that the boiler is firing.
5. Access the setting menu by pressing the and
keys for 5 seconds the icon will be shown in the
display;
6. Press the menu button four times to access Menu 5
and press the setting button once to switch the
output of the boiler to maximum (two digits will be flashing
indicating the temperature of the boiler). There will be a
cursor at the top of the display indicating the boiler is at
maximum output. If the cursor is at the bottom of the
display (indicating minimum output) press the
button
the change to maximum output;
7. If necessary adjust the screw on the gas valve (Fig. 40) to
set the CO
2
to 8.9% +/- 0.2% (NG) or 9.7% +/- 0.2%
(LPG);
8. Press the setting button once to set the combustion
control rate mode to minimum, and, if necessary, adjust
the screw on the gas valve to set the CO
2
to 8.9% +/-
0.2% (NG) or 9.7% +/- 0.2% (LPG);
9. Press the setting button again to set the combustion
rate control mode to maximum and if necessary adjust
the screw on the gas valve to set the CO
2
to 8.9% +/-
0.2% (NG) or 9.2% +/- 0.2% (LPG);
10. Reassemble in reverse order.
2. Make sure that all radiator valves are open;
3. Turn on the gas cock and check the seals on the
connections with any approved soap solution and
eliminate any leaks;
4. Press the reset button 29 (Fig. 1) the boiler will re-attempt
ignition. If the burner does not light the first time, wait 1
minute and repeat the procedure;
5. Check the minimum and maximum CO
2
values and gas
rates;- Adjust if necessary as indicated in Section 14.3
(page 29).