Bosch KWB42-3 User Manual

Gas type conversion | 63
6 720 810 590 (2015/05)
Greenstar FS
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 34).
▶ Switch the appliance ON using the ON/OFF switch.
▶ Unscrew a plug, indicated in the figure below, to open one of the flue
gas test ports.
Fig. 71 Open one of the flue gas test ports
▶ Insert the probe approximately 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. 72 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 22.
Fig. 73 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. 74, [3]) from gas valve
adjustment screw ( Fig. 74, [2]) and set CO
2
or O
2
level for
minimum nominal output.
Fig. 74 Set CO
2
or O
2
level for minimum nominal output
[1] Gas inlet pressure test point
[2] Minimum adjustment screw
[3] Minimum adjustment screw cover
▶ 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. 74, [3]) to cover the gas valve
adjustment screw.
▶ Remove flue gas probe and refit the plug into the flue gas test port
and tighten to secure.
6720810590-64.1Wo
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 22 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

Bosch KWB42-3 Specifications

General

Brand	Bosch
Model	KWB42-3
Category	Boiler
Language	English