Checking And, If Required, Adjusting The Gas/Air; Ratio - Bosch Worcester Greenstar 8000 Series Installation And Maintenance Instructions Manual

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
1
Fig. 95 Setting the adjustable venturi
[1] Security Seal
[2] Adjustable venturi
Greenstar 8000 Style – 6720883855 (2019/01)
2.
1.
0 010 007 441-001
2
0 010 020 540-002
▶ 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 or O content.
2 2
▶ Check the CO or O content at maximum rated output according to
2 2
Tab. 23 and adjust if required.
Security Seal [1] ( Fig. 95) must be removed before adjusting the Max
CO setting. Once adjustment has been made the seal must be replaced
2
with part number 8737708988.
▶ To increase the CO content, remove seal [1] and turn the adjustable
2
venturi to the left.
▶ To reduce the CO content, remove seal [1] and turn the adjustable
2
venturi to the right.
Maximum rated output
Gas type CO O
2 2
Natural gas 9.5 % 4.0 % <250ppm 8.6 %
± 0.4
Liquid 10.8 % 4.6 % <250ppm 10.2 %
propane (LPG) ± 0.4
Table 23 CO and O contents
2 2
Inspection and maintenance
0010023633-001
Minimum rated output
CO CO O CO
2 2
5.5 % <75ppm
± 0.4
5.5 % <75ppm
± 0.4
63