Bosch Worcester Greenstar 8000 Series - Checking And, if Required, Adjusting the Gas;Air; Ratio

Inspection and maintenance
63
Greenstar 8000 Style – 6720883855 (2019/01)
8.10.1 Checking and, if required, adjusting the gas/air ratio
▶ Switch off the appliance.
▶ Remove the front cover.
▶ Remove the combustion cover.
Fig. 94 Removing the combustion cover
Fig. 95 Setting the adjustable venturi
[1] Security Seal
[2] Adjustable venturi
▶ Switch on the appliance.
▶ Remove the plug from the flue gas test port.
▶ Push the flue gas probe centrally into the flue gas test port.
▶ Seal the test point.
Fig. 96 Flue gas test port
▶ To ensure heat transfer: open the radiator valves.
▶ Set the chimney sweep mode and start up the appliance at maximum
rated output.
▶ Measure the CO
2
or O
2
content.
▶ Check the CO
2
or O
2
content at maximum rated output according to
Tab. 23 and adjust if required.
Security Seal [1] ( Fig. 95) must be removed before adjusting the Max
CO
2
setting. Once adjustment has been made the seal must be replaced
with part number 8737708988.
▶ To increase the CO
2
content, remove seal [1] and turn the adjustable
venturi to the left.
▶ To reduce the CO
2
content, remove seal [1] and turn the adjustable
venturi to the right.
Table 23 CO
2
and O
2
contents
0 010 007 441-001
1.
2.
0 010 020 540-002
1
2
Maximum rated output Minimum rated output
Gas type CO
2
O
2
CO CO
2
O
2
CO
Natural gas 9.5 %
± 0.4
4.0 % <250ppm 8.6 %
± 0.4
5.5 % <75ppm
Liquid
propane (LPG)
10.8 %
± 0.4
4.6 % <250ppm 10.2 %
± 0.4
5.5 % <75ppm
0010023633-001