42
In case of any alterations, replacement of the gas valve or conversion to
another gas type, the control must be checked and reset if necessary
according to the table below:-
Gas type Natural gas H Propane P
Gas category 2H G20 3P G31 (propane)
CO
2
% at low position (L)
(service and -)
8.8 – 9.2 9.3 – 9.7
CO
2
% at high position (H)
(service and +)
8.6 – 9.6 9.5 – 10.5
Gas inlet pressure dynamic (mBar) 17-25 25-45
Gas inlet pressure static (mBar) 20 37
Gas setting ring diameter (mm) 6.95 5.35
Minimum speed (% of max)
(parameter d)
30 40
Min. starting speed (% of max)
(parameter F)
70 50
Note: See also § 7.3 (Parameters) - parameter c is default 40.
7.9 Setting gas-air control
Siemens gas valve & ignition transformer
Setting by measuring the CO
2
content of the flue gases
Remark
• A CO
2
measuring nipple must be mounted right above the
appliance in the flue discharge.
A. Dust cap (socket head wrench torx T15)
B. Setting screw for the low position (socket head wrench torx T15)
C. Off-set pressure measuring nipple
D. Inlet pressure measuring nipple
1. Switch off the appliance using the On/Off button (
- on service
display).
2. Open the flue gas measuring nipple and connect the measuring
hose.
3. Switch on the appliance using the On/Off button.
4. Set the boiler to the lowest output by simultaneously pressing the
“Service” and “–“ buttons on the operating panel until an
L
appears on the service display.
5. Measure the CO
2
value. If the CO
2
value does not correspond with the value in
the table, proceed as follows for setting:-
6. Remove the front cover of the appliance.
7. Remove the dust cap (A) with a torx T15 driver
8. Using a torx driver (T15), adjust the setting screw (B) to the correct CO
2
value
(clockwise higher and counter-clockwise lower).
9. After measuring and setting, set the boiler to the highest output by
simultaneously pressing the “Service” and “+“ buttons (twice) on the operating
panel until an
H appears on the service display.
10. Measure the CO
2
value. Check that the CO
2
value corresponds with the value in
the table.
11. If the high output CO
2
is not within the parameters allowed in the chart above,
return to low output and adjust the CO2 setting at low output before returning to
high out put to check it again. Contact the manufacturer if you encounter
difficulties.
12. Measure the CO/CO
2
ratio, (see § 7.10)
