Setting The Gas-Air Ratio (Co 2 Or O 2 ) - Bosch ZBR16-3A Series Installation And Service Instructions Manual

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