Bosch Worchester GREENSTAR ZWB 7-27 HE combi Installation And Servicing Instructions page 30

Converting the appliance to different gas types
B Turn the temperature control
shows 2.
(= max. rated heat output).
The display and the
6 720 610 332-61.1O
Fig. 43
B Measure the CO
level.
2
B Prise off the seal on the gas flow restrictor.
B Adjust the gas flow restrictor (63) to obtain the CO
level given in Table 15. Refer to fig. 44.
Fig. 44
CO
at max.
rated heat
Gas Type output
Natural gas type 9.5 %
H (23)
LPG 11.3 %
(propane)
Table 15
B Measure the CO level.
If the CO level is over 300 ppm, the gas volumetric
flow rate is too high. Reduce the gas flow rate on the
adjustable gas flow restrictor (63) until the CO level
is below 100 ppm.
B Re-adjust the CO
level if necessary.
2
30
until the display
button will flash.
63
6 720 610 332-64.1R
reading
2
CO reading
2
at min. rated
heat output
9.2 %
11.0 %
B Turn the temperature control
the display shows 1. (= min. rated heat output).
The display and the
6 720 610 332-63.1O
Fig. 45
B Measure the CO
B Remove the seal from the gas valve adjusting screw
(64) and adjust the CO
Table 15 for min. rated heat output.
2
Fig. 46
B Measure the CO level.
If the CO level is over 300 ppm, the gas volumetric
flow rate is too high. Reduce the gas flow rate on the
adjustable gas flow restrictor (63) until the CO level
is below 100 ppm.
B Re-adjust the CO
B Recheck the levels at min. and max. rated heat output
and re-adjust if necessary.
B Turn the temperature control
far as the stop so that the display shows 0.
(= Normal operating mode).
The display and the
B Press and hold the
shows [ ].
B Reset the temperature controls
original positions.
The display will revert to the CH flow temperature.
B Remove testing probe from the flue gas testing point
(234) and refit sealing plug.
B Re-seal gas valve adjusting screw and gas flow
restrictor.
B Replace outer case and secure.
anti-clockwise until
button will flash.
level.
2
level to the figure given in
2
level if necessary.
2
anti-clockwise as
button will flash.
button until the display
and
6 720 610 576 GB (02.05)
to their