Bosch ZBR16-3A Series - Setting the Gas-Air Ratio (CO 2 or O 2 )

66 | Gas type conversion
Greenstar6 720 806 992 (2015/03)
12.3 Setting the gas-air ratio (CO
2
or O
2
)
▶ Switch the appliance OFF using the ON/OFF switch.
▶ Remove the cover ( page 36).
▶ Switch the appliance ON using the ON/OFF switch.
▶ Open one of the flue gas test ports.
Fig. 77 Open one of the flue gas test ports
▶ Insert the probe approx. 2-3/4 inches (70 mm) into the test port and
seal around it.
▶ Press and hold the emissions test button until it lights up.
The display shows the supply temperature alternating with =
maximum set output in heating mode.
▶ Briefly press the emissions test button .
The display shows the supply temperature in alternation with =
maximum nominal output.
▶ Measure the CO
2
or O
2
level and the CO content of the flue gas
( Section 13).
▶ On the gas throttle, break the seal at the slot and remove the cap.
Fig. 78 Remove seal from the gas throttle
▶ Adjust the gas throttle to match the CO
2
or O
2
level for maximum
nominal output according to table 31.
Fig. 79 Set CO
2
or O
2
level for maximum nominal output
▶ Briefly press the emissions test button .
The display shows the supply temperature in alternation with =
minimum nominal output.
▶ Measure the CO
2
or O
2
level and the CO content of the flue gas
( Section 13).
▶ Remove the sealed screw ( Fig. 80, [3]) from gas valve adjustment
screw ( Fig. 80, [2]) and set CO
2
or O
2
level for minimum nominal
output.
Fig. 80 Set CO
2
or O
2
level for minimum nominal output
▶ Re-check settings at maximum and minimum nominal output and re-
adjust if necessary.
▶ Repeatedly press the emissions test button until the light goes
out.
The display returns to the supply temperature.
▶ Record the CO
2
or O
2
levels and the CO content of the flue gas in the
commissioning log.
▶ Reinstall the screw ( Fig. 80, [3]) to cover the gas valve adjustment
screw.
6 720 641 933-79.1O
1 .
2 .
6 7 2 0 6 1 2 6 5 9 - 3 7 . 1 R
Maximum nominal
output
Minimum nominal
output
Gas type CO
2
O
2
CO
2
O
2
NG 9.4 % 4.0 % 8.6 % 5.5 %
LPG (propane) 11.0 % 4.2 % 10.4% 5.1 %
Table 31 CO
2
or O
2
values at maximum and minimum nominal output
6 7 2 0 6 1 2 6 5 9 - 3 8 . 1 R
6 720 641 933-81.1O
1
3
2